1
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Shchepkin AA, Vasilyev GI, Ostryakov VM, Pavlov AK. Sharp Rise in Cosmic Ray Irradiation of Organisms on Earth Caused by a Nearby SN Shockwave Passage. ASTROBIOLOGY 2024; 24:604-612. [PMID: 38717897 DOI: 10.1089/ast.2023.0126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/27/2024]
Abstract
The work considers the modelling of nearby supernova (SN) effects on Earth's biosphere via cosmic rays (CRs) accelerated by shockwaves. The rise of the radiation background on Earth resulted from the external irradiation by CR high-energy particles and internal radiation in organisms by the decay of cosmogenic 14C is evaluated. We have taken into account that the CR flux near Earth goes up steeply when the shockwave crosses the Solar System, while in previous works the CR transport was considered as purely diffusive. Our simulations demonstrate a high rise of the external ionization of the environments at Earth's surface by atmospheric cascade particles that penetrate the first 70-100 m of water depth. Also, the cosmogenic 14C decay is able to irradiate the entire biosphere and deep ocean organisms. We analyzed the probable increase in mutation rate and estimated the distance between Earth and an SN, where the lethal effects of irradiation are possible. Our simulations demonstrate that for SN energy of around 1051 erg the lethal distance could be ∼18 pc.
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Affiliation(s)
- A A Shchepkin
- Peter the Great St. Petersburg Polytechnic University, Saint-Petersburg, Russia
| | - G I Vasilyev
- Ioffe Institute of Russian Academy of Sciences, Saint-Petersburg, Russia
| | - V M Ostryakov
- Peter the Great St. Petersburg Polytechnic University, Saint-Petersburg, Russia
| | - A K Pavlov
- Ioffe Institute of Russian Academy of Sciences, Saint-Petersburg, Russia
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2
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Siraj A, Loeb A. The New Astronomical Frontier of Interstellar Objects. ASTROBIOLOGY 2022; 22:1459-1470. [PMID: 36475962 DOI: 10.1089/ast.2021.0189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The upcoming commencement of the Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST) will greatly enhance the discovery rate of interstellar objects (ISOs). 'Oumuamua and Borisov were the first two ISOs confirmed in the Solar System, although the first interstellar meteor was detected earlier. We explore the intriguing mass budget of ejected planetesimals implied by the detections of 'Oumuamua and Borisov and explore the expected abundance of ISOs as a function of size in the solar neighborhood. Specifically, we find that a significant fraction of stellar mass must go toward producing ISOs and that ISOs outnumber Solar System objects in the Oort cloud. We consider signatures of ISOs colliding with Earth, the Moon, and neutron stars, as well as the possibility of differentiating ISOs from Solar System objects in stellar occultation surveys, and we show that these methods are observationally feasible. We introduce a test for dynamical anisotropy that is capable of determining the typical ejection speed of ISOs from their parent stars. Finally, we predict a new population of dynamically distinct ISOs originating from stars in the Galactic halo. One of the two branches of the newly established Galileo Project1 seeks to learn more about the nature of ISOs like 'Oumuamua by performing new searches and designing follow-up observations.
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Affiliation(s)
- Amir Siraj
- Department of Astronomy, Harvard University, Cambridge, Massachusetts, USA
| | - Abraham Loeb
- Department of Astronomy, Harvard University, Cambridge, Massachusetts, USA
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3
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Koll D, Faestermann T, Korschinek G, Leya I, Merchel S, Wallner A. The Dyadic Radionuclide System 60Fe / 53Mn to Distinguish Interstellar from Interplanetary 60Fe. EPJ WEB OF CONFERENCES 2022. [DOI: 10.1051/epjconf/202226011022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The discovery of live 60Fe in a deep-sea crust with proposed interstellar origin followed by evidence for elevated interplanetary 3He in the same crust raised the question on how to unambiguously identify the true production site of the identified 60Fe. Here, we show the implementation of the dyadic radionuclide system 60Fe / 53Mn to serve as a tool for the identification of surplus interstellar 60Fe over interplanetary production. The recent updates in experimental 60Fe and 53Mn data from iron meteorites as well as in production rate models confirm the validity and robustness of this dyadic system for future applications.
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4
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Boschini MJ, Della Torre S, Gervasi M, Grandi D, Jóhannesson G, La Vacca G, Masi N, Moskalenko IV, Pensotti S, Porter TA, Quadrani L, Rancoita PG, Rozza D, Tacconi M. The Discovery of a Low-energy Excess in Cosmic-Ray Iron: Evidence of the Past Supernova Activity in the Local Bubble. THE ASTROPHYSICAL JOURNAL 2021; 913:5. [PMID: 34646050 PMCID: PMC8506974 DOI: 10.3847/1538-4357/abf11c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Since its launch, the Alpha Magnetic Spectrometer-02 (AMS-02) has delivered outstanding quality measurements of the spectra of cosmic-ray (CR) species ( p ¯ , e ±, and nuclei, 1H-8O, 10Ne, 12Mg, 14Si) which resulted in a number of breakthroughs. One of the latest long-awaited surprises is the spectrum of 26Fe just published by AMS-02. Because of the large fragmentation cross section and large ionization energy losses, most of CR iron at low energies is local and may harbor some features associated with relatively recent supernova (SN) activity in the solar neighborhood. Our analysis of the new AMS-02 results, together with Voyager 1 and ACE-CRIS data, reveals an unexpected bump in the iron spectrum and in the Fe/He, Fe/O, and Fe/Si ratios at 1-2 GV, while a similar feature in the spectra of He, O, and Si and in their ratios is absent, hinting at a local source of low-energy CRs. The found excess extends the recent discoveries of radioactive 60Fe deposits in terrestrial and lunar samples and in CRs. We provide an updated local interstellar spectrum (LIS) of iron in the energy range from 1 MeV nucleon-1 to ~10 TeV nucleon-1. Our calculations employ the GALPROP-HELMOD framework, which has proved to be a reliable tool in deriving the LIS of CR p ¯ , e -, and nuclei Z ⩽ 28.
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Affiliation(s)
- M J Boschini
- INFN, Milano-Bicocca, Milano, Italy
- CINECA, Segrate, Milano, Italy
| | | | - M Gervasi
- INFN, Milano-Bicocca, Milano, Italy
- Physics Department, University of Milano-Bicocca, Milano, Italy
| | - D Grandi
- INFN, Milano-Bicocca, Milano, Italy
- Physics Department, University of Milano-Bicocca, Milano, Italy
| | - G Jóhannesson
- Science Institute, University of Iceland, Dunhaga 3, IS-107 Reykjavik, Iceland
- NORDITA, Roslagstullsbacken 23, SE-106 91 Stockholm, Sweden
| | - G La Vacca
- INFN, Milano-Bicocca, Milano, Italy
- Physics Department, University of Milano-Bicocca, Milano, Italy
| | - N Masi
- INFN, Bologna, Italy
- Physics Department, University of Bologna, Bologna, Italy
| | - I V Moskalenko
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305, USA
- Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305, USA
| | - S Pensotti
- INFN, Milano-Bicocca, Milano, Italy
- Physics Department, University of Milano-Bicocca, Milano, Italy
| | - T A Porter
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305, USA
- Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305, USA
| | - L Quadrani
- INFN, Bologna, Italy
- Physics Department, University of Bologna, Bologna, Italy
| | | | - D Rozza
- INFN, Milano-Bicocca, Milano, Italy
| | - M Tacconi
- INFN, Milano-Bicocca, Milano, Italy
- Physics Department, University of Milano-Bicocca, Milano, Italy
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Wallner A, Froehlich MB, Hotchkis MAC, Kinoshita N, Paul M, Martschini M, Pavetich S, Tims SG, Kivel N, Schumann D, Honda M, Matsuzaki H, Yamagata T. 60Fe and 244Pu deposited on Earth constrain the r-process yields of recent nearby supernovae. Science 2021; 372:742-745. [PMID: 33986180 DOI: 10.1126/science.aax3972] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 04/12/2021] [Indexed: 11/02/2022]
Abstract
Half of the chemical elements heavier than iron are produced by the rapid neutron capture process (r-process). The sites and yields of this process are disputed, with candidates including some types of supernovae (SNe) and mergers of neutron stars. We search for two isotopic signatures in a sample of Pacific Ocean crust-iron-60 (60Fe) (half-life, 2.6 million years), which is predominantly produced in massive stars and ejected in supernova explosions, and plutonium-244 (244Pu) (half-life, 80.6 million years), which is produced solely in r-process events. We detect two distinct influxes of 60Fe to Earth in the last 10 million years and accompanying lower quantities of 244Pu. The 244Pu/60Fe influx ratios are similar for both events. The 244Pu influx is lower than expected if SNe dominate r-process nucleosynthesis, which implies some contribution from other sources.
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Affiliation(s)
- A Wallner
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia. .,Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
| | - M B Froehlich
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - M A C Hotchkis
- Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia
| | - N Kinoshita
- Institute of Technology, Shimizu Corporation, Tokyo 135-8530, Japan
| | - M Paul
- Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - M Martschini
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - S Pavetich
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - S G Tims
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - N Kivel
- Laboratory of Radiochemistry, Department for Nuclear Energy and Safety, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - D Schumann
- Laboratory of Radiochemistry, Department for Nuclear Energy and Safety, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - M Honda
- Graduate School of Pure and Applied Sciences, University of Tsukuba, Ibaraki 305-8577, Japan
| | - H Matsuzaki
- Micro Analysis Laboratory, Tandem Accelerator, The University Museum, The University of Tokyo, Tokyo 113-0032, Japan
| | - T Yamagata
- Micro Analysis Laboratory, Tandem Accelerator, The University Museum, The University of Tokyo, Tokyo 113-0032, Japan
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6
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Malkov MA, Moskalenko IV. The TeV Cosmic-Ray Bump: A Message from the Epsilon Indi or Epsilon Eridani Star? THE ASTROPHYSICAL JOURNAL 2021; 911:151. [PMID: 34646049 PMCID: PMC8506973 DOI: 10.3847/1538-4357/abe855] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A recently observed bump in the cosmic-ray (CR) spectrum from 0.3 to 30 TV is likely caused by a stellar bow shock that reaccelerates preexisting CRs, which further propagate to the Sun along the magnetic field lines. Along their way, these particles generate an Iroshnikov-Kraichnan (I-K) turbulence that controls their propagation and sustains the bump. Ad hoc fitting of the bump shape requires six adjustable parameters. Our model requires none, merely depending on three physical unknowns that we constrain using the fit. These are the shock Mach number, M, its size, l ⊥, and the distance to it, ζ obs. Altogether, they define the bump rigidity R 0. With M ≈ 1.5-1.6 and R 0 ≈ 4.4 TV, the model fits the data with ≈0.08% accuracy. The fit critically requires the I-K spectrum predicted by the model and rules out the alternatives. These attributes of the fit make an accidental agreement highly unlikely. In turn, the R 0 and M derived from the fit impose the distance-size relation on the shock:ζ obs ( pc ) ~ 10 2 l ⊥ ( pc ) . For sufficiently large bow shocks, l ⊥ = 10-3-10-2 pc, we find the distance of ζ obs = 3-10 pc. Three promising stars in this range are the Scholz's Star at 6.8 pc, Epsilon Indi at 3.6 pc, and Epsilon Eridani at 3.2 pc. Based on their current positions and velocities, we propose that Epsilon Indi and Epsilon Eridani can produce the observed spectral bump. Moreover, Epsilon Eridani's position is only ~6°.7 off of the magnetic field direction in the solar neighborhood, which also changes the CR arrival direction distribution. Given the proximity of these stars, the bump appearance may change in a relatively short time.
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Affiliation(s)
- Mikhail A Malkov
- Department of Physics and CASS, University of California, San Diego, La Jolla, CA 92093, USA
| | - Igor V Moskalenko
- Hansen Experimental Physics Laboratory and Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305, USA
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7
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Crawford IA, Joy KH, Pasckert JH, Hiesinger H. The lunar surface as a recorder of astrophysical processes. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2021; 379:20190562. [PMID: 33222641 PMCID: PMC7739904 DOI: 10.1098/rsta.2019.0562] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/13/2020] [Indexed: 06/11/2023]
Abstract
The lunar surface has been exposed to the space environment for billions of years and during this time has accumulated records of a wide range of astrophysical phenomena. These include solar wind particles and the cosmogenic products of solar particle events which preserve a record of the past evolution of the Sun, and cosmogenic nuclides produced by high-energy galactic cosmic rays which potentially record the galactic environment of the Solar System through time. The lunar surface may also have accreted material from the local interstellar medium, including supernova ejecta and material from interstellar clouds encountered by the Solar System in the past. Owing to the Moon's relatively low level of geological activity, absence of an atmosphere, and, for much of its history, lack of a magnetic field, the lunar surface is ideally suited to collect these astronomical records. Moreover, the Moon exhibits geological processes able to bury and thus both preserve and 'time-stamp' these records, although gaining access to them is likely to require a significant scientific infrastructure on the lunar surface. This article is part of a discussion meeting issue 'Astronomy from the Moon: the next decades'.
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Affiliation(s)
- Ian A. Crawford
- Department of Earth and Planetary Sciences, Birkbeck College, University of London, Malet Street, London WC1E 7HX, UK
- Centre for Planetary Sciences at UCL/Birkbeck, Gower Street, London WC1E 6BT, UK
| | - Katherine H. Joy
- Department of Earth and Environmental Sciences, The University of Manchester, Oxford Road, M13 9PL Manchester, UK
| | - Jan H. Pasckert
- Institut für Planetologie, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
| | - Harald Hiesinger
- Institut für Planetologie, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
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8
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Boschini MJ, Torre SD, Gervasi M, Grandi D, Jóhannesson G, La Vacca G, Masi N, Moskalenko IV, Pensotti S, Porter TA, Quadrani L, Rancoita PG, Rozza D, Tacconi M. Inference of the Local Interstellar Spectra of Cosmic-Ray Nuclei Z ⩽ 28 with the GalProp-HelMod Framework. THE ASTROPHYSICAL JOURNAL. SUPPLEMENT SERIES 2020; 250:27. [PMID: 34711999 PMCID: PMC8549769 DOI: 10.3847/1538-4365/aba901] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Composition and spectra of Galactic cosmic rays (CRs) are vital for studies of high-energy processes in a variety of environments and on different scales, for interpretation of γ-ray and microwave observations, for disentangling possible signatures of new phenomena, and for understanding of our local Galactic neighborhood. Since its launch, AMS-02 has delivered outstanding-quality measurements of the spectra of p ¯ , e ±, and nuclei: 1H-8O, 10Ne, 12Mg, 14Si. These measurements resulted in a number of breakthroughs; however, spectra of heavier nuclei and especially low-abundance nuclei are not expected until later in the mission. Meanwhile, a comparison of published AMS-02 results with earlier data from HEAO-3-C2 indicates that HEAO-3-C2 data may be affected by undocumented systematic errors. Utilizing such data to compensate for the lack of AMS-02 measurements could result in significant errors. In this paper we show that a fraction of HEAO-3-C2 data match available AMS-02 measurements quite well and can be used together with Voyager 1 and ACE-CRIS data to make predictions for the local interstellar spectra (LIS) of nuclei that are not yet released by AMS-02. We are also updating our already-published LIS to provide a complete set from 1H-28Ni in the energy range from 1 MeV nucleon-1 to ~100-500 TeV nucleon-1, thus covering 8-9 orders of magnitude in energy. Our calculations employ the GalProp-HelMod framework, which has proved to be a reliable tool in deriving the LIS of CR p ¯ , e -, and nuclei 1H-8O.
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Affiliation(s)
- M J Boschini
- INFN, Milano-Bicocca, Milano, Italy
- CINECA, Segrate, Milano, Italy
| | | | - M Gervasi
- INFN, Milano-Bicocca, Milano, Italy
- Physics Department, University of Milano-Bicocca, Milano, Italy
| | - D Grandi
- INFN, Milano-Bicocca, Milano, Italy
- Physics Department, University of Milano-Bicocca, Milano, Italy
| | - G Jóhannesson
- Science Institute, University of Iceland, Dunhaga 3, IS-107 Reykjavik, Iceland
- NORDITA, Roslagstullsbacken 23, 106 91 Stockholm, Sweden
| | - G La Vacca
- INFN, Milano-Bicocca, Milano, Italy
- Physics Department, University of Milano-Bicocca, Milano, Italy
| | - N Masi
- INFN, Bologna, Italy
- Physics Department, University of Bologna, Bologna, Italy
| | - I V Moskalenko
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305, USA
- Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305, USA
| | - S Pensotti
- INFN, Milano-Bicocca, Milano, Italy
- Physics Department, University of Milano-Bicocca, Milano, Italy
| | - T A Porter
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305, USA
- Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305, USA
| | - L Quadrani
- INFN, Bologna, Italy
- Physics Department, University of Bologna, Bologna, Italy
| | | | - D Rozza
- INFN, Milano-Bicocca, Milano, Italy
- Physics Department, University of Milano-Bicocca, Milano, Italy
| | - M Tacconi
- INFN, Milano-Bicocca, Milano, Italy
- Physics Department, University of Milano-Bicocca, Milano, Italy
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9
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Wallner A, Feige J, Fifield LK, Froehlich MB, Golser R, Hotchkis MAC, Koll D, Leckenby G, Martschini M, Merchel S, Panjkov S, Pavetich S, Rugel G, Tims SG. 60Fe deposition during the late Pleistocene and the Holocene echoes past supernova activity. Proc Natl Acad Sci U S A 2020; 117:21873-21879. [PMID: 32839339 PMCID: PMC7486756 DOI: 10.1073/pnas.1916769117] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Nuclides synthesized in massive stars are ejected into space via stellar winds and supernova explosions. The solar system (SS) moves through the interstellar medium and collects these nucleosynthesis products. One such product is 60Fe, a radionuclide with a half-life of 2.6 My that is predominantly produced in massive stars and ejected in supernova explosions. Extraterrestrial 60Fe has been found on Earth, suggesting close-by supernova explosions ∼2 to 3 and ∼6 Ma. Here, we report on the detection of a continuous interstellar 60Fe influx on Earth over the past ∼33,000 y. This time period coincides with passage of our SS through such interstellar clouds, which have a significantly larger particle density compared to the local average interstellar medium embedding our SS for the past few million years. The interstellar 60Fe was extracted from five deep-sea sediment samples and accelerator mass spectrometry was used for single-atom counting. The low number of 19 detected atoms indicates a continued but low influx of interstellar 60Fe. The measured 60Fe time profile over the 33 ky, obtained with a time resolution of about ±9 ky, does not seem to reflect any large changes in the interstellar particle density during Earth's passage through local interstellar clouds, which could be expected if the local cloud represented an isolated remnant of the most recent supernova ejecta that traversed the Earth ∼2 to 3 Ma. The identified 60Fe influx may signal a late echo of some million-year-old supernovae with the 60Fe-bearing dust particles still permeating the interstellar medium.
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Affiliation(s)
- A Wallner
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia;
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - J Feige
- Isotope Physics, Faculty of Physics, Vienna Environmental Research Accelerator Laboratory, University of Vienna, 1090 Vienna, Austria
- Zentrum für Astronomie und Astrophysik, Technische Universität Berlin, 10623 Berlin, Germany
| | - L K Fifield
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - M B Froehlich
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - R Golser
- Isotope Physics, Faculty of Physics, Vienna Environmental Research Accelerator Laboratory, University of Vienna, 1090 Vienna, Austria
| | - M A C Hotchkis
- Centre for Accelerator Science, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia
| | - D Koll
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - G Leckenby
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - M Martschini
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
- Isotope Physics, Faculty of Physics, Vienna Environmental Research Accelerator Laboratory, University of Vienna, 1090 Vienna, Austria
| | - S Merchel
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - S Panjkov
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - S Pavetich
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - G Rugel
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - S G Tims
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
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10
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Korschinek G, Faestermann T, Poutivtsev M, Arazi A, Knie K, Rugel G, Wallner A. Supernova-Produced ^{53}Mn on Earth. PHYSICAL REVIEW LETTERS 2020; 125:031101. [PMID: 32745435 DOI: 10.1103/physrevlett.125.031101] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 04/13/2020] [Accepted: 06/18/2020] [Indexed: 06/11/2023]
Abstract
For the time period from 1.5 to 4 Myr before the present we found in deep ocean ferromanganese crusts a ^{53}Mn excess concentration in terms of ^{53}Mn/Mn of about 4×10^{-14} over that expected for cosmogenic production. We conclude that this ^{53}Mn is of supernova origin because it is detected in the same time window, about 2.5 Myr ago, where ^{60}Fe has been found earlier. This overabundance confirms the supernova origin of that ^{60}Fe. For the first time, supernova-formed ^{53}Mn has been detected and it is the second positively identified radioisotope from the same supernova. The ratio ^{53}Mn/^{60}Fe of about 14 is consistent with that expected for a SN with a 11-25 M_{⊙} progenitor mass and solar metallicity.
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Affiliation(s)
- G Korschinek
- Physik-Department, Technische Universität München, 85748 Garching, Germany
| | - T Faestermann
- Physik-Department, Technische Universität München, 85748 Garching, Germany
| | - M Poutivtsev
- Physik-Department, Technische Universität München, 85748 Garching, Germany
| | - A Arazi
- Laboratorio TANDAR, Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, B1650KNA San Martín, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Rivadavia 1917, C1033AAJ Buenos Aires, Argentina
| | - K Knie
- Physik-Department, Technische Universität München, 85748 Garching, Germany
| | - G Rugel
- Physik-Department, Technische Universität München, 85748 Garching, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - A Wallner
- Physik-Department, Technische Universität München, 85748 Garching, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
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11
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12
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Martschini M, Lachner J, Merchel S, Priller A, Steier P, Wallner A, Wieser A, Golser R. The quest for AMS of 182Hf – why poor gas gives pure beams. EPJ WEB OF CONFERENCES 2020. [DOI: 10.1051/epjconf/202023202003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The long-lived radioisotope 182Hf (T1/2 = 8.9 Ma) is of high astrophysical interest as its potential abundance in environmental archives would provide insight into recent r-process nucleosynthesis in the vicinity of our solar system. Despite substantial efforts, it could not be measured at natural abundances with conventional AMS so far due to strong isobaric interference from stable 182W. Equally important is an increase in ion source efficiency for the anions of interest.
The new Ion Laser InterAction Mass Spectrometry (ILIAMS) technique at VERA tackles the problem of elemental selectivity in AMS with a novel approach. It achieves near-complete suppression of isobar contaminants via selective laser photodetachment of decelerated anion beams in a gas-filled radio-frequency quadrupole (RFQ) ion cooler. The technique exploits differences in electron affinities (EA) within elemental or molecular isobaric systems neutralizing anions with EAs smaller than the photon energy. Alternatively, these differences in EA can also facilitate anion separation via chemical reactions with the buffer gas.
We present first results with this approach on AMS-detection of 182Hf. With He +O2 mixtures as buffer gas in the RFQ, suppression of 182WF5− vs 180HfF 5− by >105 has been demonstrated. Mass analysis of the ejected anion beam identified the formation of oxyfluorides as an important reaction channel. The overall Hf-detection efficiency at VERA presently is 1.4% and the W-corrected blank value is 182Hf/180Hf = (3.4 ± 2.1)×10−14. In addition, a survey of different sample materials for highest negative ion yields of HfF 5− with Cs-sputtering has been conducted.
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Koll D, Faestermann T, Korschinek G, Wallner A. Origin of Recent Interstellar 60Fe on Earth. EPJ WEB OF CONFERENCES 2020. [DOI: 10.1051/epjconf/202023202001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Over the last 20 years, evidence for a 2 Myr old supernova 60Fe influx onto Earth was provided by several authors. For the first time, independent investigations of samples from two different geological archives yielded conclusive data for a further, much younger 60Fe influx onto Earth. The origin of this influx is currently unclear because of the limited data available, the lack of consistent astrophysical models and a gap in the data between 50 kyr and 1 Myr. Possible astrophysical scenarios will be discussed with respect to the different influx patterns from different sources and a measurement to close the gap will be proposed.
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14
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Koll D, Korschinek G, Faestermann T, Gómez-Guzmán JM, Kipfstuhl S, Merchel S, Welch JM. Interstellar ^{60}Fe in Antarctica. PHYSICAL REVIEW LETTERS 2019; 123:072701. [PMID: 31491090 DOI: 10.1103/physrevlett.123.072701] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 05/23/2019] [Indexed: 06/10/2023]
Abstract
Earth is constantly bombarded with extraterrestrial dust containing invaluable information about extraterrestrial processes, such as structure formation by stellar explosions or nucleosynthesis, which could be traced back by long-lived radionuclides. Here, we report the very first detection of a recent ^{60}Fe influx onto Earth by analyzing 500 kg of snow from Antarctica by accelerator mass spectrometry. By the measurement of the cosmogenically produced radionuclide ^{53}Mn, an atomic ratio of ^{60}Fe/^{53}Mn=0.017 was found, significantly above cosmogenic production. After elimination of possible terrestrial sources, such as global fallout, the excess of ^{60}Fe could only be attributed to interstellar ^{60}Fe which might originate from the solar neighborhood.
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Affiliation(s)
- Dominik Koll
- Physik-Department, Technische Universität München, 85748 Garching, Germany
| | - Gunther Korschinek
- Physik-Department, Technische Universität München, 85748 Garching, Germany
- Excellence Cluster Universe, 85748 Garching, Germany
| | - Thomas Faestermann
- Physik-Department, Technische Universität München, 85748 Garching, Germany
- Excellence Cluster Universe, 85748 Garching, Germany
| | - J M Gómez-Guzmán
- Physik-Department, Technische Universität München, 85748 Garching, Germany
| | - Sepp Kipfstuhl
- Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, 27568 Bremerhaven, Germany
| | - Silke Merchel
- Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
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15
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Schumann D, Kivel N, Dressler R. Production and characterization of 60Fe standards for accelerator mass spectrometry. PLoS One 2019; 14:e0219039. [PMID: 31251777 PMCID: PMC6599215 DOI: 10.1371/journal.pone.0219039] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 06/16/2019] [Indexed: 11/19/2022] Open
Abstract
Accelerator Mass Spectrometry (AMS) is one of the most sensitive analysis techniques to measure long-lived radionuclides, reaching detection limits for isotopic ratios down to 10-15-10-16 in special cases. Its application portfolio covers nearly every field of environmental research, considering processes in the atmosphere, biosphere, hydrosphere, cryosphere, lithosphere and the cosmosphere. Normally, AMS measures the content of isotopes in comparison to a validated standard. However, in some cases like for example 60Fe, well characterized standard materials are difficult to produce due to the extreme rareness of the isotope. We report here on the manufacturing of a set of 60Fe standards, obtained by processing irradiated copper from a beam dump of the high-power proton accelerator (HIPA) at the Paul Scherrer Institute (PSI). The isotopic ratios of the standards have been adjusted via a dilution series of a master solution, isotopic content of which has been characterized by Multi Collector-Inductively Coupled Plasma-Mass Spectrometry (MC-ICP-MS). In total, we produced three samples with isotopic ratios of 1.037(6)·10-8, 1.125(7)·10-10 and 1.234 (7)·10-12, respectively. The latter had already been applied in three pioneering AMS studies investigating the remaining signal of injected matter of nearby super novae explosions in sediment archives.
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Affiliation(s)
- Dorothea Schumann
- Paul Scherrer Institute Villigen, Department for Nuclear Energy and Safety, Villigen PSI, Switzerland
- * E-mail:
| | - Niko Kivel
- Paul Scherrer Institute Villigen, Division Large Research Facilities, Villigen PSI, Switzerland
| | - Rugard Dressler
- Paul Scherrer Institute Villigen, Department for Nuclear Energy and Safety, Villigen PSI, Switzerland
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16
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Melott AL, Marinho F, Paulucci L. Hypothesis: Muon Radiation Dose and Marine Megafaunal Extinction at the End-Pliocene Supernova. ASTROBIOLOGY 2019; 19:825-830. [PMID: 30481053 DOI: 10.1089/ast.2018.1902] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Considerable data and analysis support the detection of one or more supernovae (SNe) at a distance of about 50 pc, ∼2.6 million years ago. This is possibly related to the extinction event around that time and is a member of a series of explosions that formed the Local Bubble in the interstellar medium. We build on previous work, and propagate the muon flux from SN-initiated cosmic rays from the surface to the depths of the ocean. We find that the radiation dose from the muons will exceed the total present surface dose from all sources at depths up to 1 km and will persist for at least the lifetime of marine megafauna. It is reasonable to hypothesize that this increase in radiation load may have contributed to a newly documented marine megafaunal extinction at that time.
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Affiliation(s)
- Adrian L Melott
- 1 Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas
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17
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Feige J, Wallner A, Altmeyer R, Fifield LK, Golser R, Merchel S, Rugel G, Steier P, Tims SG, Winkler SR. Limits on Supernova-Associated ^{60}Fe/^{26}Al Nucleosynthesis Ratios from Accelerator Mass Spectrometry Measurements of Deep-Sea Sediments. PHYSICAL REVIEW LETTERS 2018; 121:221103. [PMID: 30547642 DOI: 10.1103/physrevlett.121.221103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 09/20/2018] [Indexed: 06/09/2023]
Abstract
We searched for the presence of ^{26}Al in deep-sea sediments as a signature of supernova influx. Our data show an exponential dependence of ^{26}Al with the sample age that is fully compatible with radioactive decay of terrigenic ^{26}Al. The same set of samples demonstrated a clear supernova ^{60}Fe signal between 1.7 and 3.2 Myr ago. Combining our ^{26}Al data with the recently reported ^{60}Fe data results in a lower limit of 0.18_{-0.08}^{+0.15} for the local interstellar ^{60}Fe/^{26}Al isotope ratio. It compares to most of the ratios deduced from nucleosynthesis models and is within the range of the observed average galactic ^{60}Fe/^{26}Al flux ratio of (0.15±0.05).
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Affiliation(s)
- Jenny Feige
- Technische Universität Berlin, Department of Astronomy and Astrophysics, Hardenbergstr. 36, 10623 Berlin, Germany
- University of Vienna, Faculty of Physics-Isotope Research and Nuclear Physics, VERA Laboratory, Währingerstr. 17, 1090 Vienna, Austria
| | - Anton Wallner
- The Australian National University, Department of Nuclear Physics, Canberra ACT 2601, Australia
| | - Randolf Altmeyer
- Humboldt-Universität zu Berlin, Department of Mathematics, Unter den Linden 6, 10099 Berlin, Germany
| | - L Keith Fifield
- The Australian National University, Department of Nuclear Physics, Canberra ACT 2601, Australia
| | - Robin Golser
- University of Vienna, Faculty of Physics-Isotope Research and Nuclear Physics, VERA Laboratory, Währingerstr. 17, 1090 Vienna, Austria
| | - Silke Merchel
- Helmholtz-Zentrum Dresden-Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Bautzner Landstr. 400, 01328 Dresden, Germany
| | - Georg Rugel
- Helmholtz-Zentrum Dresden-Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Bautzner Landstr. 400, 01328 Dresden, Germany
| | - Peter Steier
- University of Vienna, Faculty of Physics-Isotope Research and Nuclear Physics, VERA Laboratory, Währingerstr. 17, 1090 Vienna, Austria
| | - Stephen G Tims
- The Australian National University, Department of Nuclear Physics, Canberra ACT 2601, Australia
| | - Stephan R Winkler
- University of Vienna, Faculty of Physics-Isotope Research and Nuclear Physics, VERA Laboratory, Währingerstr. 17, 1090 Vienna, Austria
- iThemba LABS-Laboratory for Accelerator Based Science, Somerset West 7129, South Africa
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19
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Rodrigues D, Negri AE, Balpardo C, Arazi A, Faestermann T, Fernandez Niello JO, Fimiani L, Gómez Guzmán JM, Hain K, Korschinek G, Ludwig P, Marti GV. Assessment of 53Mn deposition on Earth via accelerator mass spectrometry. Appl Radiat Isot 2018; 140:342-346. [PMID: 30138816 DOI: 10.1016/j.apradiso.2018.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Revised: 07/30/2018] [Accepted: 08/02/2018] [Indexed: 11/19/2022]
Abstract
The 53Mn flux onto Earth is a quantity relevant for different extraterrestrial and astrophysical questions. It is a proxy for related fluxes, such as supernova-produced material or interplanetary dust particles. In this work, we performed a first attempt to assess the 53Mn flux by measuring the 53Mn/10Be isotopic ratio in a 1400 L sample of molten Antarctic snow by AMS (Accelerator Mass Spectrometry). Using the 10Be production rate in the atmosphere, an upper limit of 5.5 × 103 atoms cm-2 yr-1 was estimated for the deposition of extraterrestrial 53Mn. This result is compatible with one of the two discrepant values existing in the literature.
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Affiliation(s)
- Darío Rodrigues
- Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, BKNA1650 San Martín, Argentina; CONICET, Av. Rivadavia 1917, C1033AAJ Buenos Aires, Argentina; Departamento de Física, FCEyN, UBA and IFIBA, Conicet, Pabellón 1, Ciudad Universitaria, 1428 Buenos Aires, Argentina.
| | - Agustín E Negri
- CONICET, Av. Rivadavia 1917, C1033AAJ Buenos Aires, Argentina; Instituto de Investigación e Ingeniería Ambiental, Universidad Nacional de San Martín, 25 de Mayo y Francia, San Martín, B1650BWA Buenos Aires, Argentina
| | - Christian Balpardo
- Laboratorio de Metrología de Radioisótopos, Centro Atómico Ezeiza, Comisión Nacional de Energía Atómica, Pbro. González y Aragón 15, Ezeiza, B1802AYA Buenos Aires, Argentina
| | - Andrés Arazi
- Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, BKNA1650 San Martín, Argentina; CONICET, Av. Rivadavia 1917, C1033AAJ Buenos Aires, Argentina
| | - Thomas Faestermann
- Technische Universität München, Fakultät für Physik, James-Franck-Straße 1, 85748 Garching, Germany
| | - Jorge O Fernandez Niello
- Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, BKNA1650 San Martín, Argentina; CONICET, Av. Rivadavia 1917, C1033AAJ Buenos Aires, Argentina; Instituto de Investigación e Ingeniería Ambiental, Universidad Nacional de San Martín, 25 de Mayo y Francia, San Martín, B1650BWA Buenos Aires, Argentina
| | - Leticia Fimiani
- Technische Universität München, Fakultät für Physik, James-Franck-Straße 1, 85748 Garching, Germany
| | - José Manuel Gómez Guzmán
- Technische Universität München, Fakultät für Physik, James-Franck-Straße 1, 85748 Garching, Germany
| | - Karin Hain
- Technische Universität München, Fakultät für Physik, James-Franck-Straße 1, 85748 Garching, Germany
| | - Gunther Korschinek
- Technische Universität München, Fakultät für Physik, James-Franck-Straße 1, 85748 Garching, Germany
| | - Peter Ludwig
- Technische Universität München, Fakultät für Physik, James-Franck-Straße 1, 85748 Garching, Germany
| | - Guillermo V Marti
- Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, BKNA1650 San Martín, Argentina
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Abstract
Recent data indicate one or more moderately nearby supernovae in the Early Pleistocene, with additional events likely in the Miocene. This has motivated more detailed computations, using new information about the nature of supernovae and the distances of these events to describe in more detail the sorts of effects that are indicated at the Earth. This short communication/review is designed to describe some of these effects so that they may possibly be related to changes in the biota around these times.
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Affiliation(s)
- Adrian L Melott
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, USA,
| | - Brian C Thomas
- Department of Physics and Astronomy, Washburn University, 1700 SW College Avenue Topeka, Kansas 66621, USA,
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21
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Czarnocka W, Karpiński S. Friend or foe? Reactive oxygen species production, scavenging and signaling in plant response to environmental stresses. Free Radic Biol Med 2018; 122:4-20. [PMID: 29331649 DOI: 10.1016/j.freeradbiomed.2018.01.011] [Citation(s) in RCA: 284] [Impact Index Per Article: 47.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 12/17/2017] [Accepted: 01/09/2018] [Indexed: 01/11/2023]
Abstract
In the natural environment, plants are exposed to a variety of biotic and abiotic stress conditions that trigger rapid changes in the production and scavenging of reactive oxygen species (ROS). The production and scavenging of ROS is compartmentalized, which means that, depending on stimuli type, they can be generated and eliminated in different cellular compartments such as the apoplast, plasma membrane, chloroplasts, mitochondria, peroxisomes, and endoplasmic reticulum. Although the accumulation of ROS is generally harmful to cells, ROS play an important role in signaling pathways that regulate acclimatory and defense responses in plants, such as systemic acquired acclimation (SAA) and systemic acquired resistance (SAR). However, high accumulations of ROS can also trigger redox homeostasis disturbance which can lead to cell death, and in consequence, to a limitation in biomass and yield production. Different ROS have various half-lifetimes and degrees of reactivity toward molecular components such as lipids, proteins, and nucleic acids. Thus, they play different roles in intra- and extra-cellular signaling. Despite their possible damaging effect, ROS should mainly be considered as signaling molecules that regulate local and systemic acclimatory and defense responses. Over the past two decades it has been proven that ROS together with non-photochemical quenching (NPQ), hormones, Ca2+ waves, and electrical signals are the main players in SAA and SAR, two physiological processes essential for plant survival and productivity in unfavorable conditions.
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Affiliation(s)
- Weronika Czarnocka
- Department of Plant Genetics, Breeding and Biotechnology, Faculty of Horticulture, Biotechnology and Landscape Architecture, Warsaw University of Life Sciences (SGGW), Nowoursynowska Street 159, 02-776 Warsaw, Poland; Department of Botany, Faculty of Agriculture and Biology, Warsaw University of Life Sciences (SGGW), Nowoursynowska Street 159, 02-776 Warsaw, Poland
| | - Stanisław Karpiński
- Department of Plant Genetics, Breeding and Biotechnology, Faculty of Horticulture, Biotechnology and Landscape Architecture, Warsaw University of Life Sciences (SGGW), Nowoursynowska Street 159, 02-776 Warsaw, Poland; The Plant Breeding and Acclimatization Institute (IHAR) - National Research Institute, Radzików, 05-870 Błonie, Poland.
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22
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Thomas BC. Photobiological Effects at Earth's Surface Following a 50 pc Supernova. ASTROBIOLOGY 2018; 18:481-490. [PMID: 29283671 PMCID: PMC5962913 DOI: 10.1089/ast.2017.1730] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 10/26/2017] [Indexed: 05/27/2023]
Abstract
We investigated the potential biological impacts at Earth's surface of stratospheric O3 depletion caused by nearby supernovae known to have occurred about 2.5 and 8 million years ago at about 50 pc distance. New and previously published atmospheric chemistry modeling results were combined with radiative transfer modeling to determine changes in surface-level solar irradiance and biological responses. We find that UVB irradiance is increased by a factor of 1.1 to 2.8, with large variation in latitude, and seasonally at high-latitude regions. Changes in UVA and PAR (visible light) are much smaller. DNA damage (in vitro) is increased by factors similar to UVB, while other biological impacts (erythema, skin cancer, cataracts, marine phytoplankton photosynthesis inhibition, and plant damage) are increased by smaller amounts. We conclude that biological impacts due to increased UV irradiance in this SN case are not mass-extinction level but might be expected to contribute to changes in species abundances; this result fits well with species turnover observed around the Pliocene-Pleistocene boundary. Key Words: UV radiation-Supernovae-Ozone-Radiative transfer. Astrobiology 18, 481-490.
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Affiliation(s)
- Brian C Thomas
- Department of Physics and Astronomy, Washburn University , Topeka, Kansas
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23
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A Way Out of the Bubble Trouble?—Upon Reconstructing the Origin of the Local Bubble and Loop I via Radioisotopic Signatures on Earth. GALAXIES 2018. [DOI: 10.3390/galaxies6010026] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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24
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Hammache F. Transfer reactions for nuclear astrophysics. EPJ WEB OF CONFERENCES 2018. [DOI: 10.1051/epjconf/201818401009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Direct measurements of cross sections at stellar energies are very challenging - if at all possible. This is essentially due to the very low cross-sections of the reactions of interest (especially when it involves charged particles), and/or to the radioactive nature of many key nuclei. Direct measurements with charged particles are often performed at higher energies and then extrapolated down to stellar energies using R-matrix calculations. However, these extrapolations are delicate because of the possible existence of unobserved low-energy or sub-threshold resonances. In order to bypass the difficulties related to direct measurements, indirect methods such as transfer reactions are used. These experiments are usually performed at higher energies and their conditions are relatively less stringent than in direct measurements. However, these methods rely on theoretical models for which the input parameters may be an important source of systematic uncer-tainties and thus need to be determined carefully. In this manuscript, a short overview on the difficulties related to direct measurements will be given as well as a description of thetransfer reaction method and the theoretical concept behind. Finally, the method will be illustrated through two recent performed studies.
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25
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Svensmark H, Enghoff MB, Shaviv NJ, Svensmark J. Increased ionization supports growth of aerosols into cloud condensation nuclei. Nat Commun 2017; 8:2199. [PMID: 29259163 PMCID: PMC5736571 DOI: 10.1038/s41467-017-02082-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 11/03/2017] [Indexed: 11/09/2022] Open
Abstract
Ions produced by cosmic rays have been thought to influence aerosols and clouds. In this study, the effect of ionization on the growth of aerosols into cloud condensation nuclei is investigated theoretically and experimentally. We show that the mass-flux of small ions can constitute an important addition to the growth caused by condensation of neutral molecules. Under atmospheric conditions the growth from ions can constitute several percent of the neutral growth. We performed experimental studies which quantify the effect of ions on the growth of aerosols between nucleation and sizes >20 nm and find good agreement with theory. Ion-induced condensation should be of importance not just in Earth’s present day atmosphere for the growth of aerosols into cloud condensation nuclei under pristine marine conditions, but also under elevated atmospheric ionization caused by increased supernova activity. Ions produced by cosmic rays have been thought to influence aerosol and cloud processes by an unknown mechanism. Here the authors show that the mass flux of ions to aerosols enhances their growth significantly, with implications for the formation of cloud condensation nuclei.
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Affiliation(s)
- H Svensmark
- National Space Institute, Technical University of Denmark, Elektrovej, Building 328, 2800, Lyngby, Denmark.
| | - M B Enghoff
- National Space Institute, Technical University of Denmark, Elektrovej, Building 328, 2800, Lyngby, Denmark
| | - N J Shaviv
- Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - J Svensmark
- National Space Institute, Technical University of Denmark, Elektrovej, Building 328, 2800, Lyngby, Denmark.,Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100, Copenhagen, Denmark
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26
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Melott AL, Thomas BC, Kachelrieß M, Semikoz DV, Overholt AC. A Supernova at 50 pc: Effects on the Earth's Atmosphere and Biota. THE ASTROPHYSICAL JOURNAL 2017; 840:105. [PMID: 30034016 PMCID: PMC6052450 DOI: 10.3847/1538-4357/aa6c57] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Recent 60Fe results have suggested that the estimated distances of supernovae in the last few million years should be reduced from ∼100 to ∼50 pc. Two events or series of events are suggested, one about 2.7 million years to 1.7 million years ago, and another about 6.5-8.7 million years ago. We ask what effects such supernovae are expected to have on the terrestrial atmosphere and biota. Assuming that the Local Bubble was formed before the event being considered, and that the supernova and the Earth were both inside a weak, disordered magnetic field at that time, TeV-PeV cosmic rays (CRs) at Earth will increase by a factor of a few hundred. Tropospheric ionization will increase proportionately, and the overall muon radiation load on terrestrial organisms will increase by a factor of ∼150. All return to pre-burst levels within 10 kyr. In the case of an ordered magnetic field, effects depend strongly on the field orientation. The upper bound in this case is with a largely coherent field aligned along the line of sight to the supernova, in which case, TeV-PeV CR flux increases are ∼104; in the case of a transverse field they are below current levels. We suggest a substantial increase in the extended effects of supernovae on Earth and in the "lethal distance" estimate; though more work is needed. This paper is an explicit follow-up to Thomas et al. We also provide more detail on the computational procedures used in both works.
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Affiliation(s)
- A L Melott
- Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045, USA
| | - B C Thomas
- Department of Physics and Astronomy, Washburn University, Topeka, KS 66621, USA
| | | | - D V Semikoz
- APC, Universite Paris Diderot, CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Sorbonne Paris Cite, 119 F-75205 Paris, France
- National Research Nuclear University "MEPHI" (Moscow Engineering Physics Institute), Kashirskoe Highway 31, M4, 115409, Russia
| | - A C Overholt
- Department of Science and Mathematics, MidAmerica Nazarene University, Olathe, KS 66062, USA
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27
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Rehm KE. The Influence of Nuclear Reactions and Nuclear Structure in Astrophysics. EPJ WEB OF CONFERENCES 2017. [DOI: 10.1051/epjconf/201716300048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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28
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Melott AL. A Possible Role for Stochastic Astrophysical Ionizing Radiation Events in the Systematic Disparity between Molecular and Fossil Dates. ASTROBIOLOGY 2017; 17:87-90. [PMID: 28026990 DOI: 10.1089/ast.2016.1527] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Major discrepancies have been noted for some time between fossil ages and molecular divergence dates for a variety of taxa. Recently, systematic trends within avian clades have been uncovered. The trends show that the disparity is much larger for mitochondrial DNA than for nuclear DNA, also that it is larger for crown fossil dates than stem fossil dates. It has been argued that this pattern is largely inconsistent with incompleteness of the fossil record as the principal driver of the disparity. A case is presented that, given the expected mutations from a fluctuating background of astrophysical radiation from such sources as supernovae, the rate of molecular clocks is variable and should increase back to a few million years, before returning to the long-term average rate. This is a possible explanation for the disparity. One test of this hypothesis is to look for an acceleration of molecular clocks at 2 to 2.5 Ma due to one or more moderately nearby supernovae known to have happened at that time. Another is to look for reduced disparity in benthic organisms of the deep ocean. In addition, due to the importance of highly penetrating muon irradiation, the disparity should be magnified for megafauna. Key Words: Extreme events in Earth history-Molecular clock-Radiation physics-Evolution. Astrobiology 17, 87-90.
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Affiliation(s)
- Adrian L Melott
- Department of Physics and Astronomy, University of Kansas , Lawrence, Kansas
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29
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Time-resolved 2-million-year-old supernova activity discovered in Earth's microfossil record. Proc Natl Acad Sci U S A 2016; 113:9232-7. [PMID: 27503888 DOI: 10.1073/pnas.1601040113] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Massive stars ([Formula: see text]), which terminate their evolution as core-collapse supernovae, are theoretically predicted to eject [Formula: see text] of the radioisotope (60)Fe (half-life 2.61 Ma). If such an event occurs sufficiently close to our solar system, traces of the supernova debris could be deposited on Earth. Herein, we report a time-resolved (60)Fe signal residing, at least partially, in a biogenic reservoir. Using accelerator mass spectrometry, this signal was found through the direct detection of live (60)Fe atoms contained within secondary iron oxides, among which are magnetofossils, the fossilized chains of magnetite crystals produced by magnetotactic bacteria. The magnetofossils were chemically extracted from two Pacific Ocean sediment drill cores. Our results show that the (60)Fe signal onset occurs around 2.6 Ma to 2.8 Ma, near the lower Pleistocene boundary, terminates around 1.7 Ma, and peaks at about 2.2 Ma.
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30
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Recent near-Earth supernovae probed by global deposition of interstellar radioactive (60)Fe. Nature 2016; 532:69-72. [PMID: 27078565 PMCID: PMC4892339 DOI: 10.1038/nature17196] [Citation(s) in RCA: 165] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Accepted: 01/28/2016] [Indexed: 11/11/2022]
Abstract
The rate of supernovae (SNe) in our local galactic neighborhood within a distance of ~100 parsec from Earth (1 parsec (pc)=3.26 light years) is estimated at 1 SN every 2-4 million years (Myr), based on the total SN-rate in the Milky Way (2.0±0.7 per century1,2). Recent massive-star and SN activity in Earth’s vicinity may be evidenced by traces of radionuclides with half-lives t1/2 ≤100 Myr3-6, if trapped in interstellar dust grains that penetrate the Solar System (SS). One such radionuclide is 60Fe (t1/2=2.6 Myr)7,8 which is ejected in supernova explosions and winds from massive stars1,2,9. Here we report that the 60Fe signal observed previously in deep-sea crusts10,11, is global, extended in time and of interstellar origin from multiple events. Deep-sea archives from all major oceans were analyzed for 60Fe deposition via accretion of interstellar dust particles. Our results, based on 60Fe atom-counting at state-of-the-art sensitivity8, reveal 60Fe interstellar influxes onto Earth 1.7–3.2 Myr and 6.5–8.7 Myr ago. The measured signal implies that a few percent of fresh 60Fe was captured in dust and deposited on Earth. Our findings indicate multiple supernova and massive-star events during the last ~10 Myr at nearby distances ≤100 pc.
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Binns WR, Israel MH, Christian ER, Cummings AC, de Nolfo GA, Lave KA, Leske RA, Mewaldt RA, Stone EC, von Rosenvinge TT, Wiedenbeck ME. Observation of the ⁶⁰Fe nucleosynthesis-clock isotope in galactic cosmic rays. Science 2016; 352:677-80. [PMID: 27103666 DOI: 10.1126/science.aad6004] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 03/18/2016] [Indexed: 11/02/2022]
Abstract
Iron-60 ((60)Fe) is a radioactive isotope in cosmic rays that serves as a clock to infer an upper limit on the time between nucleosynthesis and acceleration. We have used the ACE-CRIS instrument to collect 3.55 × 10(5) iron nuclei, with energies ~195 to ~500 mega-electron volts per nucleon, of which we identify 15 (60)Fe nuclei. The (60)Fe/(56)Fe source ratio is (7.5 ± 2.9) × 10(-5) The detection of supernova-produced (60)Fe in cosmic rays implies that the time required for acceleration and transport to Earth does not greatly exceed the (60)Fe half-life of 2.6 million years and that the (60)Fe source distance does not greatly exceed the distance cosmic rays can diffuse over this time, ⪍1 kiloparsec. A natural place for (60)Fe origin is in nearby clusters of massive stars.
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Affiliation(s)
- W R Binns
- Washington University, St. Louis, MO 63130, USA.
| | - M H Israel
- Washington University, St. Louis, MO 63130, USA.
| | - E R Christian
- NASA/Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - A C Cummings
- California Institute of Technology, Pasadena, CA 91125, USA
| | - G A de Nolfo
- NASA/Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - K A Lave
- Washington University, St. Louis, MO 63130, USA
| | - R A Leske
- California Institute of Technology, Pasadena, CA 91125, USA
| | - R A Mewaldt
- California Institute of Technology, Pasadena, CA 91125, USA
| | - E C Stone
- California Institute of Technology, Pasadena, CA 91125, USA
| | | | - M E Wiedenbeck
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
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Fimiani L, Cook DL, Faestermann T, Gómez-Guzmán JM, Hain K, Herzog G, Knie K, Korschinek G, Ludwig P, Park J, Reedy RC, Rugel G. Interstellar ^{60}Fe on the Surface of the Moon. PHYSICAL REVIEW LETTERS 2016; 116:151104. [PMID: 27127953 DOI: 10.1103/physrevlett.116.151104] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Indexed: 06/05/2023]
Abstract
A dying massive star ends in a supernova explosion ejecting a large fraction of its mass into the interstellar medium. If this happens nearby, part of the ejecta might end on Solar System bodies and, in fact, radioactive ^{60}Fe has been detected on the Pacific ocean floor in about 2 Ma old layers. Here, we report on the detection of this isotope also in lunar samples, originating presumably from the same event. The concentration of the cosmic ray produced isotope ^{53}Mn, measured in the same samples, proves the supernova origin of the ^{60}Fe. From the ^{60}Fe concentrations found we deduce a reliable value for the local interstellar fluence in the range of 1×10^{8} at/cm^{2}. Thus, we obtain constraints on the recent and nearby supernova(e).
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Affiliation(s)
- L Fimiani
- Physik Department, Technische Universität München, D-85748 Garching, Germany
| | - D L Cook
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, USA
| | - T Faestermann
- Physik Department, Technische Universität München, D-85748 Garching, Germany
| | - J M Gómez-Guzmán
- Physik Department, Technische Universität München, D-85748 Garching, Germany
| | - K Hain
- Physik Department, Technische Universität München, D-85748 Garching, Germany
| | - G Herzog
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, USA
| | - K Knie
- Physik Department, Technische Universität München, D-85748 Garching, Germany
| | - G Korschinek
- Physik Department, Technische Universität München, D-85748 Garching, Germany
| | - P Ludwig
- Physik Department, Technische Universität München, D-85748 Garching, Germany
| | - J Park
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, USA
| | - R C Reedy
- Planetary Science Institute, Los Alamos, New Mexico 87544-3826, USA
| | - G Rugel
- Physik Department, Technische Universität München, D-85748 Garching, Germany
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The locations of recent supernovae near the Sun from modelling (60)Fe transport. Nature 2016; 532:73-6. [PMID: 27078566 DOI: 10.1038/nature17424] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 02/10/2016] [Indexed: 11/08/2022]
Abstract
The signature of (60)Fe in deep-sea crusts indicates that one or more supernovae exploded in the solar neighbourhood about 2.2 million years ago. Recent isotopic analysis is consistent with a core-collapse or electron-capture supernova that occurred 60 to 130 parsecs from the Sun. Moreover, peculiarities in the cosmic ray spectrum point to a nearby supernova about two million years ago. The Local Bubble of hot, diffuse plasma, in which the Solar System is embedded, originated from 14 to 20 supernovae within a moving group, whose surviving members are now in the Scorpius-Centaurus stellar association. Here we report calculations of the most probable trajectories and masses of the supernova progenitors, and hence their explosion times and sites. The (60)Fe signal arises from two supernovae at distances between 90 and 100 parsecs. The closest occurred 2.3 million years ago at present-day galactic coordinates l = 327°, b = 11°, and the second-closest exploded about 1.5 million years ago at l = 343°, b = 25°, with masses of 9.2 and 8.8 times the solar mass, respectively. The remaining supernovae, which formed the Local Bubble, contribute to a smaller extent because they happened at larger distances and longer ago ((60)Fe has a half-life of 2.6 million years). There are uncertainties relating to the nucleosynthesis yields and the loss of (60)Fe during transport, but they do not influence the relative distribution of (60)Fe in the crust layers, and therefore our model reproduces the measured relative abundances very well.
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Wallner A, Bichler M, Buczak K, Dressler R, Fifield LK, Schumann D, Sterba JH, Tims SG, Wallner G, Kutschera W. Settling the half-life of 60Fe: fundamental for a versatile astrophysical chronometer. PHYSICAL REVIEW LETTERS 2015; 114:041101. [PMID: 25679883 DOI: 10.1103/physrevlett.114.041101] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Indexed: 06/04/2023]
Abstract
In order to resolve a recent discrepancy in the half-life of 60Fe, we performed an independent measurement with a new method that determines the 60Fe content of a material relative to 55Fe (t1/2=2.744 yr) with accelerator mass spectrometry. Our result of (2.50±0.12)×10(6) yr clearly favors the recently reported value (2.62±0.04)×10(6) yr, and rules out the older result of (1.49±0.27)×10(6) yr. The present weighted mean half-life value of (2.60±0.05)×10(6) yr substantially improves the reliability as an important chronometer for astrophysical applications in the million-year time range. This includes its use as a sensitive probe for studying recent chemical evolution of our Galaxy, the formation of the early Solar System, nucleosynthesis processes in massive stars, and as an indicator of a recent nearby supernova.
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Affiliation(s)
- A Wallner
- Department of Nuclear Physics, Australian National University, Canberra, Australian Capital Territory 2601, Australia and VERA Laboratory, Faculty of Physics, University of Vienna, 1090 Vienna, Austria
| | - M Bichler
- Atominstitut, Vienna University of Technology, 1020 Vienna, Austria
| | - K Buczak
- VERA Laboratory, Faculty of Physics, University of Vienna, 1090 Vienna, Austria and Atominstitut, Vienna University of Technology, 1020 Vienna, Austria
| | - R Dressler
- Biology and Chemistry, Paul Scherrer Institute (PSI), 5232 Villigen, Switzerland
| | - L K Fifield
- Department of Nuclear Physics, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - D Schumann
- Biology and Chemistry, Paul Scherrer Institute (PSI), 5232 Villigen, Switzerland
| | - J H Sterba
- Atominstitut, Vienna University of Technology, 1020 Vienna, Austria
| | - S G Tims
- Department of Nuclear Physics, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - G Wallner
- Institute of Inorganic Chemistry, University of Vienna, 1090 Vienna, Austria
| | - W Kutschera
- VERA Laboratory, Faculty of Physics, University of Vienna, 1090 Vienna, Austria
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Wallner A, Faestermann T, Feige J, Feldstein C, Knie K, Korschinek G, Kutschera W, Ofan A, Paul M, Quinto F, Rugel G, Steier P. Abundance of live ²⁴⁴Pu in deep-sea reservoirs on Earth points to rarity of actinide nucleosynthesis. Nat Commun 2015; 6:5956. [PMID: 25601158 PMCID: PMC4309418 DOI: 10.1038/ncomms6956] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2014] [Accepted: 11/26/2014] [Indexed: 11/09/2022] Open
Abstract
Half of the heavy elements including all actinides are produced in r-process
nucleosynthesis, whose sites and history remain a mystery. If continuously produced,
the Interstellar Medium is expected to build-up a quasi-steady state of abundances
of short-lived nuclides (with half-lives ≤100 My), including actinides
produced in r-process nucleosynthesis. Their existence in today’s
interstellar medium would serve as a radioactive clock and would establish that
their production was recent. In particular 244Pu, a radioactive
actinide nuclide (half-life=81 My), can place strong constraints on recent
r-process frequency and production yield. Here we report the detection of
live interstellar 244Pu, archived in Earth’s deep-sea
floor during the last 25 My, at abundances lower than expected from continuous
production in the Galaxy by about 2 orders of magnitude. This large discrepancy may
signal a rarity of actinide r-process nucleosynthesis sites, compatible with
neutron-star mergers or with a small subset of actinide-producing supernovae. The build-up of short-lived nuclides in the interstellar medium tells
us about production frequency and yield of heavy elements by nucleosynthesis. Wallner
et al. find a low abundance of live interstellar 244Pu detected from the
deep-sea floor, suggesting a rarity for r-process nucleosynthesis sites.
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Affiliation(s)
- A Wallner
- 1] Department of Nuclear Physics, Australian National University, Canberra, Australian Capital Territory 0200, Australia [2] VERA Laboratory, Faculty of Physics, University of Vienna, Währinger Strasse 17, A-1090 Vienna, Austria
| | - T Faestermann
- Physik Department, Technische Universität München, D-85747 Garching, Germany
| | - J Feige
- VERA Laboratory, Faculty of Physics, University of Vienna, Währinger Strasse 17, A-1090 Vienna, Austria
| | - C Feldstein
- Racah Institute of Physics, Hebrew University, Jerusalem 91904, Israel
| | - K Knie
- 1] Physik Department, Technische Universität München, D-85747 Garching, Germany [2] GSI Helmholtz-Zentrum für Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt, Germany
| | - G Korschinek
- Physik Department, Technische Universität München, D-85747 Garching, Germany
| | - W Kutschera
- VERA Laboratory, Faculty of Physics, University of Vienna, Währinger Strasse 17, A-1090 Vienna, Austria
| | - A Ofan
- Racah Institute of Physics, Hebrew University, Jerusalem 91904, Israel
| | - M Paul
- Racah Institute of Physics, Hebrew University, Jerusalem 91904, Israel
| | - F Quinto
- VERA Laboratory, Faculty of Physics, University of Vienna, Währinger Strasse 17, A-1090 Vienna, Austria
| | - G Rugel
- Physik Department, Technische Universität München, D-85747 Garching, Germany
| | - P Steier
- VERA Laboratory, Faculty of Physics, University of Vienna, Währinger Strasse 17, A-1090 Vienna, Austria
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36
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Setting the stage for habitable planets. Life (Basel) 2014; 4:35-65. [PMID: 25370028 PMCID: PMC4187148 DOI: 10.3390/life4010035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 02/10/2014] [Accepted: 02/17/2014] [Indexed: 11/17/2022] Open
Abstract
Our understanding of the processes that are relevant to the formation and maintenance of habitable planetary systems is advancing at a rapid pace, both from observation and theory. The present review focuses on recent research that bears on this topic and includes discussions of processes occurring in astrophysical, geophysical and climatic contexts, as well as the temporal evolution of planetary habitability. Special attention is given to recent observations of exoplanets and their host stars and the theories proposed to explain the observed trends. Recent theories about the early evolution of the Solar System and how they relate to its habitability are also summarized. Unresolved issues requiring additional research are pointed out, and a framework is provided for estimating the number of habitable planets in the Universe.
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38
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Feige J, Wallner A, Fifield L, Korschinek G, Merchel S, Rugel G, Steier P, Winkler S, Golser R. AMS measurements of cosmogenic and supernova-ejected radionuclides in deep-sea sediment cores. EPJ WEB OF CONFERENCES 2013. [DOI: 10.1051/epjconf/20136303003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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40
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Kivel N, Schumann D, Günther-Leopold I. Quantification of 60Fe atoms by MC-ICP-MS for the redetermination of the half-life. Anal Bioanal Chem 2013; 405:2965-72. [PMID: 23314586 DOI: 10.1007/s00216-012-6587-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Revised: 11/13/2012] [Accepted: 11/19/2012] [Indexed: 11/30/2022]
Abstract
In many scientific fields, the half-life of radionuclides plays an important role. The accurate knowledge of this parameter has direct impact on, e.g., age determination of archeological artifacts and of the elemental synthesis in the universe. In order to derive the half-life of a long-lived radionuclide, the activity and the absolute number of atoms have to be analyzed. Whereas conventional radiation measurement methods are typically applied for activity determinations, the latter can be determined with high accuracy by mass spectrometric techniques. Over the past years, the half-lives of several radionuclides have been specified by means of multiple-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) complementary to the earlier reported values mainly derived by accelerator mass spectrometry. The present paper discusses all critical aspects (amount of material, radiochemical sample preparation, interference correction, isotope dilution mass spectrometry, calculation of measurement uncertainty) for a precise analysis of the number of atoms by MC-ICP-MS exemplified for the recently published half-life determination of 60Fe (Rugel et al, Phys Rev Lett 103:072502, 2009).
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Affiliation(s)
- Niko Kivel
- Nuclear Energy and Safety, Paul Scherrer Institute (PSI), Villigen, Switzerland.
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42
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Abstract
Ionizing radiation is a ubiquitous feature of the Cosmos, from exogenous cosmic rays (CR) to the intrinsic mineral radioactivity of a habitable world, and its influences on the emergence and persistence of life are wide-ranging and profound. Much attention has already been focused on the deleterious effects of ionizing radiation on organisms and the complex molecules of life, but ionizing radiation also performs many crucial functions in the generation of habitable planetary environments and the origins of life. This review surveys the role of CR and mineral radioactivity in star formation, generation of biogenic elements, and the synthesis of organic molecules and driving of prebiotic chemistry. Another major theme is the multiple layers of shielding of planetary surfaces from the flux of cosmic radiation and the various effects on a biosphere of violent but rare astrophysical events such as supernovae and gamma-ray bursts. The influences of CR can also be duplicitous, such as limiting the survival of surface life on Mars while potentially supporting a subsurface biosphere in the ocean of Europa. This review highlights the common thread that ionizing radiation forms between the disparate component disciplines of astrobiology.
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Affiliation(s)
- Lewis R Dartnell
- UCL Institute for Origins, University College London, London, UK.
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Melott AL, Thomas BC. Astrophysical ionizing radiation and Earth: a brief review and census of intermittent intense sources. ASTROBIOLOGY 2011; 11:343-361. [PMID: 21545268 DOI: 10.1089/ast.2010.0603] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Cosmic radiation backgrounds are a constraint on life, and their distribution will affect the Galactic Habitable Zone. Life on Earth has developed in the context of these backgrounds, and characterizing event rates will elaborate the important influences. This in turn can be a base for comparison with other potential life-bearing planets. In this review, we estimate the intensities and rates of occurrence of many kinds of strong radiation bursts by astrophysical entities, ranging from gamma-ray bursts at cosmological distances to the Sun itself. Many of these present potential hazards to the biosphere; on timescales long compared with human history, the probability of an event intense enough to disrupt life on the land surface or in the oceans becomes large. Both photons (e.g., X-rays) and high-energy protons and other nuclei (often called "cosmic rays") constitute hazards. For either species, one of the mechanisms that comes into play even at moderate intensities is the ionization of Earth's atmosphere, which leads through chemical changes (specifically, depletion of stratospheric ozone) to increased ultraviolet B flux from the Sun reaching the surface. UVB is extremely hazardous to most life due to its strong absorption by the genetic material DNA and subsequent breaking of chemical bonds. This often leads to mutation or cell death. It is easily lethal to the microorganisms that lie at the base of the food chain in the ocean. We enumerate the known sources of radiation and characterize their intensities at Earth and rates or upper limits on these quantities. When possible, we estimate a "lethal interval," our best estimate of how often a major extinction-level event is probable given the current state of knowledge; we base these estimates on computed or expected depletion of stratospheric ozone. In general, moderate-level events are dominated by the Sun, but the far more severe infrequent events are probably dominated by gamma-ray bursts and supernovae. We note for the first time that so-called "short-hard" gamma-ray bursts are a substantial threat, comparable in magnitude to supernovae and greater than that of the higher-luminosity long bursts considered in most past work. Given their precursors, short bursts may come with little or no warning.
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Affiliation(s)
- Adrian L Melott
- Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045, USA.
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Abstract
Recent developments in analytical instrumentation have led to revolutionary discoveries in cosmochemistry. Instrumental advances have been made along two lines: (i) increase in spatial resolution and sensitivity of detection, allowing for the study of increasingly smaller samples, and (ii) increase in the precision of isotopic analysis that allows more precise dating, the study of isotopic heterogeneity in the Solar System, and other studies. A variety of instrumental techniques are discussed, and important examples of discoveries are listed. Instrumental techniques and instruments include the ion microprobe, laser ablation gas MS, Auger EM, resonance ionization MS, accelerator MS, transmission EM, focused ion-beam microscopy, atom probe tomography, X-ray absorption near-edge structure/electron loss near-edge spectroscopy, Raman microprobe, NMR spectroscopy, and inductively coupled plasma MS.
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Rugel G, Faestermann T, Knie K, Korschinek G, Poutivtsev M, Schumann D, Kivel N, Günther-Leopold I, Weinreich R, Wohlmuther M. New Measurement of the 60Fe Half-Life. PHYSICAL REVIEW LETTERS 2009; 103:072502. [PMID: 19792637 DOI: 10.1103/physrevlett.103.072502] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2009] [Indexed: 05/28/2023]
Abstract
We have made a new determination of the half-life of the radioactive isotope 60Fe using high precision measurements of the number of 60Fe atoms and their activity in a sample containing over 10(15) 60Fe atoms. Our new value for the half-life of 60Fe is (2.62+/-0.04) x 10(6) yr, significantly above the previously reported value of (1.49+/-0.27) x 10(6) yr. Our new measurement for the lifetime of 60Fe has significant implications for interpretations of galactic nucleosynthesis, for determinations of formation time scales of solids in the early Solar System, and for the interpretation of live 60Fe measurements from supernova-ejecta deposits on Earth.
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Affiliation(s)
- G Rugel
- Technische Universität München, Garching D-85748, Germany
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Uberseder E, Reifarth R, Schumann D, Dillmann I, Pardo CD, Görres J, Heil M, Käppeler F, Marganiec J, Neuhausen J, Pignatari M, Voss F, Walter S, Wiescher M. Measurement of the 60Fe(n, gamma)61Fe Cross Section at Stellar Temperatures. PHYSICAL REVIEW LETTERS 2009; 102:151101. [PMID: 19518614 DOI: 10.1103/physrevlett.102.151101] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2008] [Indexed: 05/27/2023]
Abstract
Observations of galactic gamma-ray activity have challenged the current understanding of nucleosynthesis in massive stars. Recent measurements of (60)Fe abundances relative to ;{26}Al;{g} have underscored the need for accurate nuclear information concerning the stellar production of (60)Fe. In light of this motivation, a first measurement of the stellar (60)Fe(n, gamma)(61)Fe cross section, the predominant destruction mechanism of (60)Fe, has been performed by activation at the Karlsruhe Van de Graaff accelerator. Results show a Maxwellian averaged cross section at kT = 25 keV of 9.9 +/-_{1.4(stat)};{2.8(syst)}mbarn, a significant reduction in uncertainty with respect to existing theoretical discrepancies. This result will serve to significantly constrain models of (60)Fe nucleosynthesis in massive stars.
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Affiliation(s)
- E Uberseder
- University of Notre Dame, Department of Physics, Notre Dame, Indiana, USA
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47
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Fitoussi C, Raisbeck GM, Knie K, Korschinek G, Faestermann T, Goriely S, Lunney D, Poutivtsev M, Rugel G, Waelbroeck C, Wallner A. Search for supernova-produced 60Fe in a marine sediment. PHYSICAL REVIEW LETTERS 2008; 101:121101. [PMID: 18851357 DOI: 10.1103/physrevlett.101.121101] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Revised: 02/05/2008] [Indexed: 05/26/2023]
Abstract
An 60Fe peak in a deep-sea FeMn crust has been interpreted as due to the signature left by the ejecta of a supernova explosion close to the solar system 2.8+/-0.4 Myr ago [Knie, Phys. Rev. Lett. 93, 171103 (2004)10.1103/PhysRevLett.93.171103]. In an attempt to confirm this interpretation with better time resolution and obtain a more direct flux estimate, we measured 60Fe concentrations along a dated marine sediment. We find no 60Fe peak at the expected level from 1.7 to 3.2 Myr ago. Possible causes for the discrepancy are discussed.
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Affiliation(s)
- C Fitoussi
- Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM) IN2P3/CNRS, Université Paris Sud, Bâtiment 108, Orsay, France
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Thomas BC, Melott AL, Fields BD, Anthony-Twarog BJ. Superluminous supernovae: no threat from eta Carinae. ASTROBIOLOGY 2008; 8:9-16. [PMID: 18199005 DOI: 10.1089/ast.2007.0181] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Recently, Supernova 2006gy was noted as the most luminous ever recorded, with a total radiated energy of approximately 10(44) Joules. It was proposed that the progenitor may have been a massive evolved star similar to eta Carinae, which resides in our own Galaxy at a distance of about 2.3 kpc. eta Carinae appears ready to detonate. Although it is too distant to pose a serious threat as a normal supernova, and given that its rotation axis is unlikely to produce a gamma-ray burst oriented toward Earth, eta Carinae is about 30,000 times nearer than 2006gy, and we re-evaluate it as a potential superluminous supernova. We have found that, given the large ratio of emission in the optical to the X-ray, atmospheric effects are negligible. Ionization of the atmosphere and concomitant ozone depletion are unlikely to be important. Any cosmic ray effects should be spread out over approximately 10(4) y and similarly unlikely to produce any serious perturbation to the biosphere. We also discuss a new possible effect of supernovae-e-ndocrine disruption induced by blue light near the peak of the optical spectrum. This is a possibility for nearby supernovae at distances too large to be considered "dangerous" for other reasons. However, due to reddening and extinction by the interstellar medium, eta Carinae is unlikely to trigger such effects to any significant degree.
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Affiliation(s)
- Brian C Thomas
- Department of Physics and Astronomy, Washburn University, Topeka, Kansas 66621, USA.
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49
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Basu S, Stuart FM, Schnabel C, Klemm V. Galactic-cosmic-ray-produced 3He in a ferromanganese crust: any supernova 60Fe excess on earth? PHYSICAL REVIEW LETTERS 2007; 98:141103. [PMID: 17501264 DOI: 10.1103/physrevlett.98.141103] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2006] [Indexed: 05/15/2023]
Abstract
An excess of 60Fe in 2.4-3.2 x 10(6) year old ferromanganese crust (237 KD) from the deep Pacific Ocean has been considered as evidence for the delivery of debris from a nearby supernova explosion to Earth. Extremely high ;{3}He/;{4}He (up to 6.12 x 10(-3)) and 3He concentrations (up to 8 x 10(9) atoms/g) measured in 237 KD cannot be supernova-derived. The helium is produced by galactic cosmic rays (GCR) and delivered in micrometeorites that have survived atmospheric entry to be trapped by the crust. 60Fe is produced by GCR reactions on Ni in extraterrestrial material. The maximum (3)He/(60)Fe of 237 KD (80-850) is comparable to the GCR (3)He/(60)Fe production ratio (400-500) predicted for Ni-bearing minerals in iron meteorites. The excess 60Fe can be plausibly explained by the presence of micrometeorites trapped by the crust, rather than injection from a supernova source.
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Affiliation(s)
- S Basu
- Isotope Geosciences Unit, Scottish Universities Environmental Research Centre, East Kilbride G75 0QF, United Kingdom.
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Gonzalez G. Habitable zones in the universe. ORIGINS LIFE EVOL B 2005; 35:555-606. [PMID: 16254692 DOI: 10.1007/s11084-005-5010-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2004] [Accepted: 03/15/2005] [Indexed: 10/25/2022]
Abstract
Habitability varies dramatically with location and time in the universe. This was recognized centuries ago, but it was only in the last few decades that astronomers began to systematize the study of habitability. The introduction of the concept of the habitable zone was key to progress in this area. The habitable zone concept was first applied to the space around a star, now called the Circumstellar Habitable Zone. Recently, other, vastly broader, habitable zones have been proposed. We review the historical development of the concept of habitable zones and the present state of the research. We also suggest ways to make progress on each of the habitable zones and to unify them into a single concept encompassing the entire universe.
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Affiliation(s)
- Guillermo Gonzalez
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa, 50011, USA.
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