101
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Snapshots capture the early stages of a distant stellar explosion. Nature 2022. [PMID: 36352105 DOI: 10.1038/d41586-022-03330-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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102
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Hristopulos D. Boltzmann–Gibbs Random Fields with Mesh-free Precision Operators Based on Smoothed Particle Hydrodynamics. Theor Probability and Math Statist 2022. [DOI: 10.1090/tpms/1180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Boltzmann–Gibbs random fields are defined in terms of the exponential expression
exp
(
−
H
)
\exp \left (-\mathcal {H}\right )
, where
H
\mathcal {H}
is a suitably defined energy functional of the field states
x
(
s
)
x(\mathbf {s})
. This paper presents a new Boltzmann–Gibbs model which features local interactions in the energy functional. The interactions are embodied in a spatial coupling function which uses smoothed kernel-function approximations of spatial derivatives inspired from the theory of smoothed particle hydrodynamics. A specific model for the interactions based on a second-degree polynomial of the Laplace operator is studied. An explicit, mesh-free expression of the spatial coupling function (precision function) is derived for the case of the squared exponential (Gaussian) smoothing kernel. This coupling function allows the model to seamlessly extend from discrete data vectors to continuum fields. Connections with Gaussian Markov random fields and the Matérn field with
ν
=
1
\nu =1
are established.
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103
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Ezell C, Lazarian A, Loeb A. A Lunar Backup Record of Humanity. Signals 2022; 3:823-829. [DOI: 10.3390/signals3040049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The risk of a catastrophic or existential disaster for our civilization is increasing this century. A significant motivation for a near-term space settlement is the opportunity to safeguard civilization in the event of a planetary-scale disaster. A catastrophic event could destroy the significant cultural, scientific, and technological progress on Earth. However, early space settlements can preserve records of human activity by maintaining a backup data storage system. The backup can also store information about the events leading up to the disaster. The system would improve the ability of early space settlers to recover our civilization after collapse. We show that advances in laser communications and data storage enable the development of a data storage system on the lunar surface with a sufficient uplink data rate and storage capacity to preserve valuable information about the achievements of our civilization and the chronology of the disaster.
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104
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Chen NL, Gans B, Hartweg S, Garcia GA, Boyé-Péronne S, Loison JC. Unravelling the electronic structure of the silicon dimer using threshold photoelectron spectroscopy. Mol Phys 2022. [DOI: 10.1080/00268976.2022.2140721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Ning L. Chen
- Institut des Sciences Moléculaires d'Orsay, CNRS, Université Paris-Saclay, Orsay, France
| | - Bérenger Gans
- Institut des Sciences Moléculaires d'Orsay, CNRS, Université Paris-Saclay, Orsay, France
| | | | | | - Séverine Boyé-Péronne
- Institut des Sciences Moléculaires d'Orsay, CNRS, Université Paris-Saclay, Orsay, France
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105
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Abbasi R, Ackermann M, Adams J, Aguilar JA, Ahlers M, Ahrens M, Alameddine JM, Alispach C, Alves AA, Amin NM, Andeen K, Anderson T, Anton G, Argüelles C, Ashida Y, Axani S, Bai X, Balagopal V. A, Barbano A, Barwick SW, Bastian B, Basu V, Baur S, Bay R, Beatty JJ, Becker KH, Becker Tjus J, Bellenghi C, BenZvi S, Berley D, Bernardini E, Besson DZ, Binder G, Bindig D, Blaufuss E, Blot S, Boddenberg M, Bontempo F, Borowka J, Böser S, Botner O, Böttcher J, Bourbeau E, Bradascio F, Braun J, Brinson B, Bron S, Brostean-Kaiser J, Browne S, Burgman A, Burley RT, Busse RS, Campana MA, Carnie-Bronca EG, Chen C, Chen Z, Chirkin D, Choi K, Clark BA, Clark K, Classen L, Coleman A, Collin GH, Conrad JM, Coppin P, Correa P, Cowen DF, Cross R, Dappen C, Dave P, De Clercq C, DeLaunay JJ, Delgado López D, Dembinski H, Deoskar K, Desai A, Desiati P, de Vries KD, de Wasseige G, de With M, DeYoung T, Diaz A, Díaz-Vélez JC, Dittmer M, Dujmovic H, Dunkman M, DuVernois MA, Dvorak E, Ehrhardt T, Eller P, Engel R, Erpenbeck H, Evans J, Evenson PA, Fan KL, Fazely AR, Fedynitch A, Feigl N, Fiedlschuster S, Fienberg AT, Filimonov K, Finley C, Fischer L, Fox D, Franckowiak A, Friedman E, Fritz A, Fürst P, Gaisser TK, Gallagher J, Ganster E, Garcia A, Garrappa S, Gerhardt L, Ghadimi A, Glaser C, Glauch T, Glüsenkamp T, Goldschmidt A, Gonzalez JG, Goswami S, Grant D, Grégoire T, Griswold S, Günther C, Gutjahr P, Haack C, Hallgren A, Halliday R, Halve L, Halzen F, Ha Minh M, Hanson K, Hardin J, Harnisch AA, Haungs A, Hebecker D, Helbing K, Henningsen F, Hettinger EC, Hickford S, Hignight J, Hill C, Hill GC, Hoffman KD, Hoffmann R, Hokanson-Fasig B, Hoshina K, Huang F, Huber M, Huber T, Hultqvist K, Hünnefeld M, Hussain R, Hymon K, In S, Iovine N, Ishihara A, Jansson M, Japaridze GS, Jeong M, Jin M, Jones BJP, Kang D, Kang W, Kang X, Kappes A, Kappesser D, Kardum L, Karg T, Karl M, Karle A, Katz U, Kauer M, Kellermann M, Kelley JL, Kheirandish A, Kin K, Kintscher T, Kiryluk J, Klein SR, Koirala R, Kolanoski H, Kontrimas T, Köpke L, Kopper C, Kopper S, Koskinen DJ, Koundal P, Kovacevich M, Kowalski M, Kozynets T, Kun E, Kurahashi N, Lad N, Lagunas Gualda C, Lanfranchi JL, Larson MJ, Lauber F, Lazar JP, Lee JW, Leonard K, Leszczyńska A, Li Y, Lincetto M, Liu QR, Liubarska M, Lohfink E, Lozano Mariscal CJ, Lu L, Lucarelli F, Ludwig A, Luszczak W, Lyu Y, Ma WY, Madsen J, Mahn KBM, Makino Y, Mancina S, Mariş IC, Martinez-Soler I, Maruyama R, Mase K, McElroy T, McNally F, Mead JV, Meagher K, Mechbal S, Medina A, Meier M, Meighen-Berger S, Micallef J, Mockler D, Montaruli T, Moore RW, Morse R, Moulai M, Naab R, Nagai R, Nahnhauer R, Naumann U, Necker J, Nguyen LV, Niederhausen H, Nisa MU, Nowicki SC, Nygren D, Obertacke Pollmann A, Oehler M, Oeyen B, Olivas A, O’Sullivan E, Pandya H, Pankova DV, Park N, Parker GK, Paudel EN, Paul L, Pérez de los Heros C, Peters L, Peterson J, Philippen S, Pieper S, Pittermann M, Pizzuto A, Plum M, Popovych Y, Porcelli A, Prado Rodriguez M, Price PB, Pries B, Przybylski GT, Raab C, Rack-Helleis J, Raissi A, Rameez M, Rawlins K, Rea IC, Rehman A, Reichherzer P, Reimann R, Renzi G, Resconi E, Reusch S, Rhode W, Richman M, Riedel B, Roberts EJ, Robertson S, Roellinghoff G, Rongen M, Rott C, Ruhe T, Ryckbosch D, Rysewyk Cantu D, Safa I, Saffer J, Sanchez Herrera SE, Sandrock A, Sandroos J, Santander M, Sarkar S, Sarkar S, Satalecka K, Schaufel M, Schieler H, Schindler S, Schmidt T, Schneider A, Schneider J, Schröder FG, Schumacher L, Schwefer G, Sclafani S, Seckel D, Seunarine S, Sharma A, Shefali S, Silva M, Skrzypek B, Smithers B, Snihur R, Soedingrekso J, Soldin D, Spannfellner C, Spiczak GM, Spiering C, Stachurska J, Stamatikos M, Stanev T, Stein R, Stettner J, Steuer A, Stezelberger T, Stokstad R, Stürwald T, Stuttard T, Sullivan GW, Taboada I, Ter-Antonyan S, Tilav S, Tischbein F, Tollefson K, Tönnis C, Toscano S, Tosi D, Trettin A, Tselengidou M, Tung CF, Turcati A, Turcotte R, Turley CF, Twagirayezu JP, Ty B, Unland Elorrieta MA, Valtonen-Mattila N, Vandenbroucke J, van Eijndhoven N, Vannerom D, van Santen J, Verpoest S, Walck C, Watson TB, Weaver C, Weigel P, Weindl A, Weiss MJ, Weldert J, Wendt C, Werthebach J, Weyrauch M, Whitehorn N, Wiebusch CH, Williams DR, Wolf M, Woschnagg K, Wrede G, Wulff J, Xu XW, Yanez JP, Yoshida S, Yu S, Yuan T, Zhang Z, Zhelnin P. Evidence for neutrino emission from the nearby active galaxy NGC 1068. Science 2022; 378:538-543. [DOI: 10.1126/science.abg3395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A supermassive black hole, obscured by cosmic dust, powers the nearby active galaxy NGC 1068. Neutrinos, which rarely interact with matter, could provide information on the galaxy’s active core. We searched for neutrino emission from astrophysical objects using data recorded with the IceCube neutrino detector between 2011 and 2020. The positions of 110 known gamma-ray sources were individually searched for neutrino detections above atmospheric and cosmic backgrounds. We found that NGC 1068 has an excess of
79
−
20
+
22
neutrinos at tera–electron volt energies, with a global significance of 4.2σ, which we interpret as associated with the active galaxy. The flux of high-energy neutrinos that we measured from NGC 1068 is more than an order of magnitude higher than the upper limit on emissions of tera–electron volt gamma rays from this source.
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106
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Murase K. Neutrinos unveil hidden galactic activities. Science 2022; 378:474-475. [DOI: 10.1126/science.ade4190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
An obscured supermassive black hole may be producing high-energy cosmic neutrinos
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Affiliation(s)
- Kohta Murase
- Department of Physics, Department of Astronomy and Astrophysics, and Institute for Gravitation and the Cosmos, Pennsylvania State University, University Park, PA, USA
- School of Natural Sciences, Institute for Advanced Study, Princeton, NJ, USA
- Center for Gravitational Physics and Quantum Information, Yukawa Institute for Theoretical Physics, Kyoto, Japan
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107
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Taverna R, Turolla R, Muleri F, Heyl J, Zane S, Baldini L, González-Caniulef D, Bachetti M, Rankin J, Caiazzo I, Di Lalla N, Doroshenko V, Errando M, Gau E, Kırmızıbayrak D, Krawczynski H, Negro M, Ng M, Omodei N, Possenti A, Tamagawa T, Uchiyama K, Weisskopf MC, Agudo I, Antonelli LA, Baumgartner WH, Bellazzini R, Bianchi S, Bongiorno SD, Bonino R, Brez A, Bucciantini N, Capitanio F, Castellano S, Cavazzuti E, Ciprini S, Costa E, De Rosa A, Del Monte E, Di Gesu L, Di Marco A, Donnarumma I, Dovčiak M, Ehlert SR, Enoto T, Evangelista Y, Fabiani S, Ferrazzoli R, Garcia JA, Gunji S, Hayashida K, Iwakiri W, Jorstad SG, Karas V, Kitaguchi T, Kolodziejczak JJ, La Monaca F, Latronico L, Liodakis I, Maldera S, Manfreda A, Marin F, Marinucci A, Marscher AP, Marshall HL, Matt G, Mitsuishi I, Mizuno T, Ng SCY, O’Dell SL, Oppedisano C, Papitto A, Pavlov GG, Peirson AL, Perri M, Pesce-Rollins M, Pilia M, Poutanen J, Puccetti S, Ramsey BD, Ratheesh A, Romani RW, Sgrò C, Slane P, Soffitta P, Spandre G, Tavecchio F, Tawara Y, Tennant AF, Thomas NE, Tombesi F, Trois A, Tsygankov SS, Vink J, Wu K, Xie F. Polarized x-rays from a magnetar. Science 2022; 378:646-650. [DOI: 10.1126/science.add0080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Magnetars are neutron stars with ultra-strong magnetic fields, which can be observed in x-rays. Polarization measurements could provide information on their magnetic fields and surface properties. We observe polarized x-rays from the magnetar 4U 0142+61 using the Imaging X-ray Polarimetry Explorer, finding a linear polarization degree of 13.5 ± 0.8% averaged over the 2 to 8 keV band. The polarization changes with energy: the degree is 15.0 ± 1.0% at 2 to 4 keV, drops below the instrumental sensitivity around 4 to 5 keV, and rises to 35.2 ± 7.1% at 5.5 to 8 keV. The polarization angle also changes by 90° around 4 to 5 keV. These results are consistent with a model in which thermal radiation from the magnetar surface is reprocessed by scattering off charged particles in the magnetosphere.
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Affiliation(s)
- Roberto Taverna
- Department of Physics and Astronomy, University of Padova, Padova I-35131, Italy
| | - Roberto Turolla
- Department of Physics and Astronomy, University of Padova, Padova I-35131, Italy
- Mullard Space Science Laboratory, University College London, Holmbury St Mary Dorking RH5 6NT, UK
| | - Fabio Muleri
- Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica (INAF), Roma I-00133, Italy
| | - Jeremy Heyl
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Silvia Zane
- Mullard Space Science Laboratory, University College London, Holmbury St Mary Dorking RH5 6NT, UK
| | - Luca Baldini
- Dipartimento di Fisica Enrico Fermi, Università di Pisa, Pisa I-56127, Italy
- Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Pisa, Pisa I-56127, Italy
| | - Denis González-Caniulef
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Matteo Bachetti
- Osservatorio Astronomico di Cagliari, INAF, Selargius I-09047, Italy
| | - John Rankin
- Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica (INAF), Roma I-00133, Italy
| | - Ilaria Caiazzo
- Theoretical AstroPhysics Including Relativity and Cosmology, Caltech, Pasadena, CA 91125, USA
| | - Niccolò Di Lalla
- Deparment of Physics and Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305, USA
| | - Victor Doroshenko
- Institut für Astronomie und Astrophysik, Universität Tübingen, Tübingen 72076, Germany
| | - Manel Errando
- Physics Department and McDonnell Center for the Space Sciences, Washington University, St. Louis, MO 63130, USA
| | - Ephraim Gau
- Physics Department and McDonnell Center for the Space Sciences, Washington University, St. Louis, MO 63130, USA
| | - Demet Kırmızıbayrak
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Henric Krawczynski
- Physics Department and McDonnell Center for the Space Sciences, Washington University, St. Louis, MO 63130, USA
| | - Michela Negro
- University of Maryland, Baltimore County, Baltimore, MD 21250, USA
- NASA Goddard Space Flight Center (GSFC), Greenbelt, MD 20771, USA
- Center for Research and Exploration in Space Science and Technology, NASA/GSFC, Greenbelt, MD 20771, USA
| | - Mason Ng
- Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Nicola Omodei
- Deparment of Physics and Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305, USA
| | - Andrea Possenti
- Osservatorio Astronomico di Cagliari, INAF, Selargius I-09047, Italy
| | - Toru Tamagawa
- RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601, Japan
| | - Keisuke Uchiyama
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601, Japan
| | | | - Ivan Agudo
- Instituto de Astrofísica de Andalucía, 18008 Granada, Spain
| | - Lucio A. Antonelli
- Osservatorio Astronomico di Roma, INAF, Monte Porzio Catone 00040, Italy
- Space Science Data Center (SSDC), Agenzia Spaziale Italiana (ASI), Roma 00133, Italy
| | | | - Ronaldo Bellazzini
- Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Pisa, Pisa I-56127, Italy
| | - Stefano Bianchi
- Dipartimento di Matematica e Fisica, Università degli Studi Roma Tre, Roma 00146, Italy
| | | | - Raffaella Bonino
- INFN Sezione di Torino, Torino 10125, Italy
- Dipartimento di Fisica, Università degli Studi di Torino, Torino 10125, Italy
| | - Alessandro Brez
- Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Pisa, Pisa I-56127, Italy
| | - Niccolò Bucciantini
- Osservatorio Astrofisico di Arcetri, INAF, Firenze 50125, Italy
- Dipartimento di Fisica e Astronomia, Università degli Studi di Firenze, Sesto Fiorentino 50019, Italy
- INFN Sezione di Firenze, Sesto Fiorentino 50019, Italy
| | - Fiamma Capitanio
- Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica (INAF), Roma I-00133, Italy
| | - Simone Castellano
- Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Pisa, Pisa I-56127, Italy
| | | | - Stefano Ciprini
- Space Science Data Center (SSDC), Agenzia Spaziale Italiana (ASI), Roma 00133, Italy
- INFN Sezione di Roma Tor Vergata, Roma 00133, Italy
| | - Enrico Costa
- Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica (INAF), Roma I-00133, Italy
| | - Alessandra De Rosa
- Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica (INAF), Roma I-00133, Italy
| | - Ettore Del Monte
- Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica (INAF), Roma I-00133, Italy
| | | | - Alessandro Di Marco
- Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica (INAF), Roma I-00133, Italy
| | | | - Michal Dovčiak
- Astronomical Institute of the Czech Academy of Sciences, 14100 Praha 4, Czech Republic
| | - Steven R. Ehlert
- NASA Marshall Space Flight Center (MSFC), Huntsville, AL 35812, USA
| | - Teruaki Enoto
- RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Yuri Evangelista
- Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica (INAF), Roma I-00133, Italy
| | - Sergio Fabiani
- Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica (INAF), Roma I-00133, Italy
| | - Riccardo Ferrazzoli
- Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica (INAF), Roma I-00133, Italy
| | | | - Shuichi Gunji
- Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata-shi 990-8560, Japan
| | | | - Wataru Iwakiri
- Department of Physics, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Svetlana G. Jorstad
- Institute for Astrophysical Research, Boston University, Boston, MA 02215, USA
- Laboratory of Observational Astrophysics, St. Petersburg University, St. Petersburg 199034, Russia
| | - Vladimir Karas
- Astronomical Institute of the Czech Academy of Sciences, 14100 Praha 4, Czech Republic
| | - Takao Kitaguchi
- RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | | | - Fabio La Monaca
- Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica (INAF), Roma I-00133, Italy
| | | | - Ioannis Liodakis
- Finnish Centre for Astronomy with the European Southern Observatory, University of Turku, 20014 Turku, Finland
| | | | - Alberto Manfreda
- Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Pisa, Pisa I-56127, Italy
| | - Frédéric Marin
- Observatoire Astronomique de Strasbourg, Université de Strasbourg, 67000 Strasbourg, France
| | | | - Alan P. Marscher
- Institute for Astrophysical Research, Boston University, Boston, MA 02215, USA
| | - Herman L. Marshall
- Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Giorgio Matt
- Dipartimento di Matematica e Fisica, Università degli Studi Roma Tre, Roma 00146, Italy
| | - Ikuyuki Mitsuishi
- Division of Particle and Astrophysical Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602, Japan
| | - Tsunefumi Mizuno
- Hiroshima Astrophysical Science Center, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Stephen C.-Y. Ng
- Department of Physics, The University of Hong Kong, Pokfulam, Hong Kong
| | | | | | - Alessandro Papitto
- Osservatorio Astronomico di Roma, INAF, Monte Porzio Catone 00040, Italy
| | - George G. Pavlov
- Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16801, USA
| | - Abel L. Peirson
- Deparment of Physics and Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305, USA
| | - Matteo Perri
- Osservatorio Astronomico di Roma, INAF, Monte Porzio Catone 00040, Italy
- Space Science Data Center (SSDC), Agenzia Spaziale Italiana (ASI), Roma 00133, Italy
| | | | - Maura Pilia
- Osservatorio Astronomico di Cagliari, INAF, Selargius I-09047, Italy
| | - Juri Poutanen
- Department of Physics and Astronomy, University of Turku, 20014 Turku, Finland
- Space Research Institute of the Russian Academy of Sciences, Moscow 117997, Russia
| | - Simonetta Puccetti
- Space Science Data Center (SSDC), Agenzia Spaziale Italiana (ASI), Roma 00133, Italy
| | - Brian D. Ramsey
- NASA Marshall Space Flight Center (MSFC), Huntsville, AL 35812, USA
| | - Ajay Ratheesh
- Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica (INAF), Roma I-00133, Italy
| | - Roger W. Romani
- Deparment of Physics and Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305, USA
| | - Carmelo Sgrò
- Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Pisa, Pisa I-56127, Italy
| | - Patrick Slane
- Center for Astrophysics, Harvard & Smithsonian, Cambridge, MA 02138, USA
| | - Paolo Soffitta
- Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica (INAF), Roma I-00133, Italy
| | - Gloria Spandre
- Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Pisa, Pisa I-56127, Italy
| | | | - Yuzuru Tawara
- Division of Particle and Astrophysical Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602, Japan
| | - Allyn F. Tennant
- NASA Marshall Space Flight Center (MSFC), Huntsville, AL 35812, USA
| | | | - Francesco Tombesi
- Dipartimento di Fisica, Università degli Studi di Roma Tor Vergata, Roma 00133, Italy
| | - Alessio Trois
- Osservatorio Astronomico di Cagliari, INAF, Selargius I-09047, Italy
| | - Sergey S. Tsygankov
- Department of Physics and Astronomy, University of Turku, 20014 Turku, Finland
- Space Research Institute of the Russian Academy of Sciences, Moscow 117997, Russia
| | - Jacco Vink
- Anton Pannekoek Institute for Astronomy, University of Amsterdam, 1098 XH Amsterdam, Netherlands
| | - Kinwah Wu
- Mullard Space Science Laboratory, University College London, Holmbury St Mary Dorking RH5 6NT, UK
| | - Fei Xie
- Guangxi Key Laboratory for Relativistic Astrophysics, School of Physical Science and Technology, Guangxi University, Nanning 530004, China
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108
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Cattaneo F, Hughes DW. How was the Earth–Moon system formed? New insights from the geodynamo. Proc Natl Acad Sci U S A 2022; 119. [PMID: 36279439 PMCID: PMC9636973 DOI: 10.1073/pnas.2120682119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The most widely accepted scenario for the formation of the Earth–Moon system involves a dramatic impact between the proto-Earth and some other cosmic body. Many features of the present-day Earth–Moon system provide constraints on the nature of this impact. Any model of the history of the Earth must account for the physical, geochemical, petrological, and dynamical evidence. These constraints notwithstanding, there are several radically different impact models that could in principle account for all the evidence. Thus, in the absence of further constraints, we may never know for sure how the Earth–Moon system was formed. Here, we put forward the idea that additional constraints are indeed provided by the fact that the Earth is strongly magnetized. It is universally accepted that the Earth’s magnetic field is maintained by a dynamo operating in the outer liquid core. However, because of the rapid rotation of the Earth, this dynamo has the peculiar property that it can maintain a strong field but cannot amplify a weak one. Therefore, the Earth must have been magnetized at a very early epoch, either preimpact or as a result of the impact itself. Either way, any realistic model of the formation of the Earth–Moon system must include magnetic field evolution. This requirement may ultimately constrain the models sufficiently to discriminate between the various candidates.
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109
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Nkambule SM, Mabuza ON. Studies of Mutual Neutralization in Collisions Involving Mg+/H−, Na+/H−, Li+/H− and Li+/Cl−. Heliyon 2022; 8:e11443. [PMID: 36387438 PMCID: PMC9647365 DOI: 10.1016/j.heliyon.2022.e11443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 09/20/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022] Open
Abstract
The Landau-Zener model is used to systematically compute mutual neutralization cross sections for collisions between Mg+/H−, Na+/H−, Li+/H− and Li+/Cl−. Potential energy curves for electronic states that are relevant for mutual neutralization are taken from available literature. Where non-adiabatic couplings are available, they are utilized to compute the diabatic potential energy curves, crossing distance and electronic couplings. In cases where non-adiabatic couplings are not available, they are approximated using a Lorentzian function. The reaction cross sections are computed for the energy range 0.001 eV to 1000 eV. The results are compared with other available experimental and theoretical results and are found to be very comparable. There is an observable trend in the reaction cross section involving ions of metals and hydrogen at collision energies below 10 eV, with the heaviest metal showing the largest reaction cross section and the lightest metal with the lowest cross section. At collision energies below 10 eV, isotope effect is also found to have an effect on the reaction cross section for Li+/Cl−.
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Affiliation(s)
- Sifiso M. Nkambule
- Department of Physics, Faculty of Science and Engineering, University of Eswatini, Private bag 4 Kwaluseni, M201, Swaziland
- Corresponding author.
| | - Oscar N. Mabuza
- Department of Physics, Faculty of Science and Engineering, University of Eswatini, Private bag 4 Kwaluseni, M201, Swaziland
- Department of Physics, Faculty of Science Education, William Pitcher College, P.O. Box 87 Manzini, M200, Swaziland
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Paul D, Yang Z, Suits AG, Parker DH, Kaiser RI. Photodissociation dynamics of xylene isomers C6H4(CH3)2 at 157 nm using an ultracompact velocity map imaging spectrometer – The C7H7 channel. Chem Phys Lett 2022; 807:140064. [DOI: 10.1016/j.cplett.2022.140064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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111
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Croswell K. Seeking answers, planetary scientists plot a return to the nearest ice giant. Proc Natl Acad Sci U S A 2022; 119:e2216692119. [PMID: 36264821 DOI: 10.1073/pnas.2216692119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
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112
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Pignatari M, Psaltis A. An underground route to grasping the Milky Way’s oldest stars. Nature 2022; 610:640-641. [DOI: 10.1038/d41586-022-03367-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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113
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Zhang L, He J, deBoer RJ, Wiescher M, Heger A, Kahl D, Su J, Odell D, Chen Y, Li X, Wang J, Zhang L, Cao F, Zhang H, Zhang Z, Jiang X, Wang L, Li Z, Song L, Zhao H, Sun L, Wu Q, Li J, Cui B, Chen L, Ma R, Li E, Lian G, Sheng Y, Li Z, Guo B, Zhou X, Zhang Y, Xu H, Cheng J, Liu W. Measurement of 19F(p, γ)20Ne reaction suggests CNO breakout in first stars. Nature 2022; 610:656-660. [DOI: 10.1038/s41586-022-05230-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 08/11/2022] [Indexed: 11/09/2022]
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114
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Song Z, Liu X, Zhang M, Xu J, Feng Y, Zhang B, Wang W, Liu J, Shao C, Yu D, Guo Y, Chen L. K X-ray Emission for Slow Oxygen Ions Approaching a Copper Metal Surface. Atoms 2022; 10:124. [DOI: 10.3390/atoms10040124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
We report on the K X-ray emission for 9–140 keV oxygen ions with initial charge states from 3 to 7 approaching a copper surface. The peak center of the measured X-ray spectrum slightly shifts towards higher energies with the increasing of the initial charge state of the incident ions. For the collisions of oxygen ions with no K-vacancies (q = 3–6), the X-ray yield per incident ion increases gradually with the projectile’s kinetic energy, while for the O7+ ions (with a K-vacancy) it is nearly independent of the energy. The K-shell ionization cross-sections for the oxygen ions with no K-vacancies obtained from the experiments are well consistent with the calculations of the binary encounter approximation model when the collision energy is larger than 30 keV, whereas they are several times larger than the theoretical values at collision energies of less than 30 keV.
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115
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Pieroni M, Ricciardone A, Barausse E. Detectability and parameter estimation of stellar origin black hole binaries with next generation gravitational wave detectors. Sci Rep 2022; 12:17940. [PMID: 36289256 DOI: 10.1038/s41598-022-19540-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Accepted: 08/30/2022] [Indexed: 11/24/2022] Open
Abstract
We consider stellar-origin black hole binaries, which are among the main astrophysical sources for next generation gravitational wave (GW) detectors such as the Einstein Telescope (ET) and Cosmic Explorer (CE). Using population models calibrated with the most recent LIGO/Virgo results from O3b run, we show that ET and CE will be capable of detecting tens of thousands of such sources (and virtually all of those present in our past light cone up to \documentclass[12pt]{minimal}
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\begin{document}$$z\lesssim 1$$\end{document}z≲1 for CE) with a signal-to-noise ratio up to several hundreds, irrespective of the detector design. When it comes to parameter estimation, we use a Fisher-matrix analysis to assess the impact of the design on the estimation of the intrinsic and extrinsic parameters. We find that the CE detector, consisting of two distinct \documentclass[12pt]{minimal}
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\begin{document}$$L-$$\end{document}L-shape interferometers, has better sky localization performance compared to ET in its triangular configuration. We also find that the network is typically capable of measuring the chirp mass, symmetric mass ratio and spins of the binary at order of \documentclass[12pt]{minimal}
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Yang Z, Doddipatla S, He C, Goettl SJ, Kaiser RI, Jasper AW, Gomes ACR, Galvão BRL. Can third-body stabilisation of bimolecular collision complexes in cold molecular clouds happen? Mol Phys 2022. [DOI: 10.1080/00268976.2022.2134832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Zhenghai Yang
- Department of Chemistry, University of Hawai’i at Manoa, Honolulu, HI, USA
| | | | - Chao He
- Department of Chemistry, University of Hawai’i at Manoa, Honolulu, HI, USA
| | - Shane J. Goettl
- Department of Chemistry, University of Hawai’i at Manoa, Honolulu, HI, USA
| | - Ralf I. Kaiser
- Department of Chemistry, University of Hawai’i at Manoa, Honolulu, HI, USA
| | - Ahren W. Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL, USA
| | - Alexandre C. R. Gomes
- Centro Federal de Educação Tecnológica de Minas Gerais, CEFET-MG, Minas Gerais, Brazil
| | - Breno R. L. Galvão
- Centro Federal de Educação Tecnológica de Minas Gerais, CEFET-MG, Minas Gerais, Brazil
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117
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Trappitsch R, Shulaker DZ, Ong W, Savina MR, Isselhardt BH. Resonance ionization of zirconium. J Radioanal Nucl Chem. [DOI: 10.1007/s10967-022-08581-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
AbstractMeasuring the isotopic composition of trace Zr in presolar stardust grains allows us to study the environment of slow neutron-capture nucleosynthesis in asymptotic giant branch stars. Here, we present a newly characterized Zr resonance ionization scheme that can be saturated with state-of-the-art titanium-sapphire lasers and yields a useful yield of (5.4 ± 0.4)%. Resonance ionization is achieved in two steps: after first being excited with a photon at 319.215 nm, neutral Zr atoms are then ionized with a photon at 388.988 nm, where both wavelengths are reported as in vacuum.
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Abstract
Large-scale computational molecular models provide scientists a means to investigate the effect of microscopic details on emergent mesoscopic behavior. Elucidating the relationship between variations on the molecular scale and macroscopic observable properties facilitates an understanding of the molecular interactions driving the properties of real world materials and complex systems (e.g., those found in biology, chemistry, and materials science). As a result, discovering an explicit, systematic connection between microscopic nature and emergent mesoscopic behavior is a fundamental goal for this type of investigation. The molecular forces critical to driving the behavior of complex heterogeneous systems are often unclear. More problematically, simulations of representative model systems are often prohibitively expensive from both spatial and temporal perspectives, impeding straightforward investigations over possible hypotheses characterizing molecular behavior. While the reduction in resolution of a study, such as moving from an atomistic simulation to that of the resolution of large coarse-grained (CG) groups of atoms, can partially ameliorate the cost of individual simulations, the relationship between the proposed microscopic details and this intermediate resolution is nontrivial and presents new obstacles to study. Small portions of these complex systems can be realistically simulated. Alone, these smaller simulations likely do not provide insight into collectively emergent behavior. However, by proposing that the driving forces in both smaller and larger systems (containing many related copies of the smaller system) have an explicit connection, systematic bottom-up CG techniques can be used to transfer CG hypotheses discovered using a smaller scale system to a larger system of primary interest. The proposed connection between different CG systems is prescribed by (i) the CG representation (mapping) and (ii) the functional form and parameters used to represent the CG energetics, which approximate potentials of mean force (PMFs). As a result, the design of CG methods that facilitate a variety of physically relevant representations, approximations, and force fields is critical to moving the frontier of systematic CG forward. Crucially, the proposed connection between the system used for parametrization and the system of interest is orthogonal to the optimization used to approximate the potential of mean force present in all systematic CG methods. The empirical efficacy of machine learning techniques on a variety of tasks provides strong motivation to consider these approaches for approximating the PMF and analyzing these approximations.
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119
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Gu Y, Wu L, Zhu B. Detection of inelastic dark matter via electron recoils in SENSEI. Int J Clin Exp Med 2022. [DOI: 10.1103/physrevd.106.075004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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120
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Abstract
Graph-based descriptors, such as bond-order matrices and adjacency matrices, offer a simple and compact way of categorizing molecular structures; furthermore, such descriptors can be readily used to catalog chemical reactions (i.e., bond-making and -breaking). As such, a number of graph-based methodologies have been developed with the goal of automating the process of generating chemical reaction network models describing the possible mechanistic chemistry in a given set of reactant species. Here, we outline the evolution of these graph-based reaction discovery schemes, with particular emphasis on more recent methods incorporating graph-based methods with semiempirical and ab initio electronic structure calculations, minimum-energy path refinements, and transition state searches. Using representative examples from homogeneous catalysis and interstellar chemistry, we highlight how these schemes increasingly act as "virtual reaction vessels" for interrogating mechanistic questions. Finally, we highlight where challenges remain, including issues of chemical accuracy and calculation speeds, as well as the inherent challenge of dealing with the vast size of accessible chemical reaction space.
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Affiliation(s)
- Idil Ismail
- Department of Chemistry, University of Warwick, CoventryCV4 7AL, United Kingdom
| | | | - Scott Habershon
- Department of Chemistry, University of Warwick, CoventryCV4 7AL, United Kingdom
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121
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Liu X, Tong L. Numerical study of gas bubble rising in liquid sodium using advanced MPS method. Nuclear Engineering and Design 2022. [DOI: 10.1016/j.nucengdes.2022.111924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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122
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Zhang Q, Sharma U, Dennis JA, Scifo A, Kuitems M, Büntgen U, Owens MJ, Dee MW, Pope BJS. Modelling cosmic radiation events in the tree-ring radiocarbon record. Proc Math Phys Eng Sci 2022. [DOI: 10.1098/rspa.2022.0497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Annually resolved measurements of the radiocarbon content in tree-rings have revealed rare sharp rises in carbon-14 production. These ‘Miyake events’ are likely produced by rare increases in cosmic radiation from the Sun or other energetic astrophysical sources. The radiocarbon produced is not only circulated through the Earth’s atmosphere and oceans, but also absorbed by the biosphere and locked in the annual growth rings of trees. To interpret high-resolution tree-ring radiocarbon measurements therefore necessitates modelling the entire global carbon cycle. Here, we introduce ‘
ticktack
’ (
https://github.com/SharmaLlama/ticktack/
), the first open-source Python package that connects box models of the carbon cycle with modern Bayesian inference tools. We use this to analyse all public annual
14
C
tree data, and infer posterior parameters for all six known Miyake events. They do not show a consistent relationship to the solar cycle, and several display extended durations that challenge either astrophysical or geophysical models.
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Affiliation(s)
- Qingyuan Zhang
- School of Mathematics and Physics, University of Queensland,St Lucia, Queensland 4072, Australia
| | - Utkarsh Sharma
- School of Mathematics and Physics, University of Queensland,St Lucia, Queensland 4072, Australia
| | - Jordan A. Dennis
- School of Mathematics and Physics, University of Queensland,St Lucia, Queensland 4072, Australia
| | - Andrea Scifo
- Centre for Isotope Research, University of Groningen, Groningen, The Netherlands
| | - Margot Kuitems
- Centre for Isotope Research, University of Groningen, Groningen, The Netherlands
| | - Ulf Büntgen
- Department of Geography, University of Cambridge, Cambridge CB2 3EN, UK
- Global Change Research Institute (CzechGlobe), Czech Academy of Sciences, 60300 Brno, Czech Republic
- Department of Geography, Faculty of Science, Masaryk University, 61137 Brno, Czech Republic
- Swiss Federal Research Institute (WSL), 8903 Birmensdorf, Switzerland
| | - Mathew J. Owens
- Department of Meteorology, University of Reading, Earley Gate,PO Box 243, Reading RG6 6BB, UK
| | - Michael W. Dee
- Centre for Isotope Research, University of Groningen, Groningen, The Netherlands
| | - Benjamin J. S. Pope
- School of Mathematics and Physics, University of Queensland,St Lucia, Queensland 4072, Australia
- Centre for Astrophysics, University of Southern Queensland,West Street, Toowoomba, Queensland 4350, Australia
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123
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Blue Bird J. The gas about Stephan's Quintet reveals a history of collision. Nature 2022; 610:458-459. [PMID: 36261546 DOI: 10.1038/d41586-022-03218-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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124
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Zhao J, Zhang L, Yue D, Liu D, Gao S, Wang L, Meng Q. Effect of the reactant vibration on quantum dynamics of the reaction H + CH(v = 0,1,2, j = 0) → H2 + C based on a new CH2(X3A″) potential energy surface. Chem Phys 2022. [DOI: 10.1016/j.chemphys.2022.111677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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125
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Bugnet L. Vibrations probe magnetic fields inside evolved stars. Nature 2022; 610:35-6. [PMID: 36198775 DOI: 10.1038/d41586-022-02979-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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126
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Li G, Deheuvels S, Ballot J, Lignières F. Magnetic fields of 30 to 100 kG in the cores of red giant stars. Nature 2022; 610:43-46. [PMID: 36198777 DOI: 10.1038/s41586-022-05176-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 08/02/2022] [Indexed: 11/09/2022]
Abstract
A red giant star is an evolved low- or intermediate-mass star that has exhausted its central hydrogen content, leaving a helium core and a hydrogen-burning shell. Oscillations of stars can be observed as periodic dimmings and brightenings in the optical light curves. In red giant stars, non-radial acoustic waves couple to gravity waves and give rise to mixed modes, which behave as pressure modes in the envelope and gravity modes in the core. These modes have previously been used to measure the internal rotation of red giants1,2, leading to the conclusion that purely hydrodynamical processes of angular momentum transport from the core are too inefficient3. Magnetic fields could produce the additional required transport4-6. However, owing to the lack of direct measurements of magnetic fields in stellar interiors, little is currently known about their properties. Asteroseismology can provide direct detection of magnetic fields because, like rotation, the fields induce shifts in the oscillation mode frequencies7-12. Here we report the measurement of magnetic fields in the cores of three red giant stars observed with the Kepler13 satellite. The fields induce shifts that break the symmetry of dipole mode multiplets. We thus measure field strengths ranging from about 30 kilogauss to about 100 kilogauss in the vicinity of the hydrogen-burning shell and place constraints on the field topology.
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Affiliation(s)
- Gang Li
- IRAP, Université de Toulouse, CNRS, CNES, UPS, Toulouse, France
| | | | - Jérôme Ballot
- IRAP, Université de Toulouse, CNRS, CNES, UPS, Toulouse, France
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128
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Brady RP, Yurchenko SN, Kim GS, Somogyi W, Tennyson J. An ab initio study of the rovibronic spectrum of sulphur monoxide (SO): diabatic vs. adiabatic representation. Phys Chem Chem Phys 2022; 24:24076-24088. [PMID: 36172791 DOI: 10.1039/d2cp03051a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present an ab initio study of the rovibronic spectra of sulphur monoxide (32S16O) using internally contracted multireference configuration interaction (ic-MRCI) method and aug-cc-pV5Z basis sets. It covers 13 electronic states X3Σ-, a1Δ, b1Σ+, c1Σ-, A''3Σ+, A'3Δ, A3Π, B3Σ-, C3Π, d1Π, e1Π, C'3Π, and (3)1Π ranging up to 66 800 cm-1. The ab initio spectroscopic model includes 13 potential energy curves, 23 dipole and transition dipole moment curves, 23 spin-orbit curves, and 14 electronic angular momentum curves. A diabatic representation is built by removing the avoided crossings between the spatially degenerate pairs C3Π-C'3Π and e1Π-(3)1Π through a property-based diabatisation method. We also present non-adiabatic couplings and diabatic couplings for these avoided crossing systems. All phases for our coupling curves are defined, and consistent, providing the first fully reproducible spectroscopic model of SO covering the wavelength range longer than 147 nm. Finally, an ab initio rovibronic spectrum of SO is computed.
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Affiliation(s)
- R P Brady
- Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London, UK.
| | - S N Yurchenko
- Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London, UK.
| | - G-S Kim
- Dharma College, Dongguk University, 30, Pildong-ro 1-gil, Jung-gu, Seoul 04620, Korea
| | - W Somogyi
- Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London, UK.
| | - J Tennyson
- Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London, UK.
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Richardson V, Valença Ferreira de Aragão E, He X, Pirani F, Mancini L, Faginas-Lago N, Rosi M, Martini LM, Ascenzi D. Fragmentation of interstellar methanol by collisions with He˙ +: an experimental and computational study. Phys Chem Chem Phys 2022; 24:22437-22452. [PMID: 36102850 DOI: 10.1039/d2cp02458f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Methanol is a key species in astrochemistry as its presence and reactivity provides a primary route to the synthesis of more complex interstellar organic molecules (iCOMs) that may eventually be incorporated in newly formed planetary systems. In the interstellar medium, methanol is formed by hydrogenation of CO ices on grains, and its fate upon collisions with interstellar ions should be accounted for to correctly model iCOM abundances in objects at various stages of stellar evolution. The absolute cross sections (CSs) and branching ratios (BRs) for the collisions of He˙+ ions with CH3OH are measured, as a function of the collision energy, using a Guided Ion Beam Mass Spectrometer (GIB-MS). Insights into the dissociative electron (charge) exchange mechanism have been obtained by computing the entrance and exit multidimensional Potential Energy Surfaces (PESs) and by modelling the non-adiabatic transitions using an improved Landau-Zener-Stückelberg approach. Notably, the dynamical treatment reproducing the experimental findings includes a strong orientation effect of the system formed by the small He˙+ ion and the highly polar CH3OH molecule, in the electric field gradient associated to the strongly anisotropic intermolecular interaction. This is a stereodynamical effect that plays a fundamental role in collision events occurring under a variety of conditions, with kinetic energy confined within intervals ranging from the sub-thermal to the hyper-thermal regime.
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Affiliation(s)
| | - Emília Valença Ferreira de Aragão
- Department of Chemistry, Biology and Biotechnology, Università degli studi di Perugia, Perugia, Italy.,Master-Tec s.r.l., Via Sicilia 41, Perugia, Italy
| | - Xiao He
- Department of Physics, University of Trento, Trento, Italy.
| | - Fernando Pirani
- Department of Chemistry, Biology and Biotechnology, Università degli studi di Perugia, Perugia, Italy.,Department of Civil and Environmental Engineering, Università degli studi di Perugia, Perugia, Italy
| | - Luca Mancini
- Department of Chemistry, Biology and Biotechnology, Università degli studi di Perugia, Perugia, Italy
| | - Noelia Faginas-Lago
- Department of Chemistry, Biology and Biotechnology, Università degli studi di Perugia, Perugia, Italy.,Master-Tec s.r.l., Via Sicilia 41, Perugia, Italy
| | - Marzio Rosi
- Department of Civil and Environmental Engineering, Università degli studi di Perugia, Perugia, Italy
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Carniato S. Valence-shell ionization of acetyl cyanide: simulation of the photoelectron and infra-red spectra. Phys Chem Chem Phys 2022; 24:24246-24263. [PMID: 36169150 DOI: 10.1039/d2cp02674k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The vibrational envelopes of the first and second lines of the acetyl cyanide valence photoelectron spectrum [Katsumata et al., J. Electron Spectrosc. Relat. Phenom., 2000, 49, 113] in the gas phase have been simulated considering the Taylor expansion of the dipole moment from zero up to the second order as well as the changes of geometries/frequencies/normal modes between the initial neutral electronic ground state and the final (15a'(-1), 3a''(-1)) cationic states. It is shown that the vibrational profile of the first band (A') extending over 3500 cm-1 with a vibrational spacing of 500 cm-1 is not due solely to the overtones (v = 0 → v' = 1, 2, 3,…) of the C-CO bending mode as previously suggested but results from a collection of (v = 0 → v' = 1) transitions with frequencies multiple of 500 cm-1 associated with the CO stretching at 1550 cm-1, C-C stretching at 1045 cm-1 and C-CO, C-CN bending modes at 370/500 cm-1 completed by combination bands. Our calculations also reveal that the structureless and asymmetric shape of the second band (A'') is due to the activation of the torsion mode at low-frequency (ω ≈ 150 cm-1) induced by the rotation (60 degrees) of the methyl group blurring the main vibrational progression (ω ≈ 1115 cm-1) corresponding to the cooperative motions of the methyl CH bending and C-CO bending/CO stretching. Infra-red spectra of the fundamental and both the 15a'(-1) and 3a''(-1) cationic states were finally simulated. In contrast to the photoemission spectra, the infrared intensity of the CO stretching motion is very weak. The spectra are mainly dominated by the v = 0 → v = 1 transition of the CN stretching and the CH symmetric bending/stretching modes, providing complementary information between photoemission and infra-red spectroscopies to capture the nature of the cationic states in acetyl-cyanide.
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Affiliation(s)
- Stéphane Carniato
- Laboratoire de Chimie Physique, Matière et Rayonnement, UMR 7614, Sorbonne Université, 4, Place Jussieu, 75231 Paris Cedex 05, France.
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131
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Baleato Lizancos A, Ferraro S. Impact of extragalactic foregrounds on internal delensing of the CMB
B
-mode polarization. Int J Clin Exp Med 2022. [DOI: 10.1103/physrevd.106.063534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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132
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Mifsud DV, Herczku P, Rácz R, Rahul KK, Kovács STS, Juhász Z, Sulik B, Biri S, McCullough RW, Kaňuchová Z, Ioppolo S, Hailey PA, Mason NJ. Energetic electron irradiations of amorphous and crystalline sulphur-bearing astrochemical ices. Front Chem 2022; 10:1003163. [PMID: 36226122 PMCID: PMC9549411 DOI: 10.3389/fchem.2022.1003163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 08/30/2022] [Indexed: 11/13/2022] Open
Abstract
Laboratory experiments have confirmed that the radiolytic decay rate of astrochemical ice analogues is dependent upon the solid phase of the target ice, with some crystalline molecular ices being more radio-resistant than their amorphous counterparts. The degree of radio-resistance exhibited by crystalline ice phases is dependent upon the nature, strength, and extent of the intermolecular interactions that characterise their solid structure. For example, it has been shown that crystalline CH3OH decays at a significantly slower rate when irradiated by 2 keV electrons at 20 K than does the amorphous phase due to the stabilising effect imparted by the presence of an extensive array of strong hydrogen bonds. These results have important consequences for the astrochemistry of interstellar ices and outer Solar System bodies, as they imply that the chemical products arising from the irradiation of amorphous ices (which may include prebiotic molecules relevant to biology) should be more abundant than those arising from similar irradiations of crystalline phases. In this present study, we have extended our work on this subject by performing comparative energetic electron irradiations of the amorphous and crystalline phases of the sulphur-bearing molecules H2S and SO2 at 20 K. We have found evidence for phase-dependent chemistry in both these species, with the radiation-induced exponential decay of amorphous H2S being more rapid than that of the crystalline phase, similar to the effect that has been previously observed for CH3OH. For SO2, two fluence regimes are apparent: a low-fluence regime in which the crystalline ice exhibits a rapid exponential decay while the amorphous ice possibly resists decay, and a high-fluence regime in which both phases undergo slow exponential-like decays. We have discussed our results in the contexts of interstellar and Solar System ice astrochemistry and the formation of sulphur allotropes and residues in these settings.
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Affiliation(s)
- Duncan V. Mifsud
- Centre for Astrophysics and Planetary Science, School of Physical Sciences, University of Kent, Canterbury, United Kingdom
- Institute for Nuclear Research (Atomki), Debrecen, Hungary
- *Correspondence: Duncan V. Mifsud, ; Péter Herczku, ; Nigel J. Mason,
| | - Péter Herczku
- Institute for Nuclear Research (Atomki), Debrecen, Hungary
- *Correspondence: Duncan V. Mifsud, ; Péter Herczku, ; Nigel J. Mason,
| | - Richárd Rácz
- Institute for Nuclear Research (Atomki), Debrecen, Hungary
| | - K. K. Rahul
- Institute for Nuclear Research (Atomki), Debrecen, Hungary
| | | | - Zoltán Juhász
- Institute for Nuclear Research (Atomki), Debrecen, Hungary
| | - Béla Sulik
- Institute for Nuclear Research (Atomki), Debrecen, Hungary
| | - Sándor Biri
- Institute for Nuclear Research (Atomki), Debrecen, Hungary
| | - Robert W. McCullough
- Department of Physics and Astronomy, School of Mathematics and Physics, Queen’s University Belfast, Belfast, United Kingdom
| | - Zuzana Kaňuchová
- Astronomical Institute, Slovak Academy of Sciences, Tatranská Lomnica, Slovakia
| | - Sergio Ioppolo
- School of Electronic Engineering and Computer Science, Queen Mary University of London, London, United Kingdom
| | - Perry A. Hailey
- Centre for Astrophysics and Planetary Science, School of Physical Sciences, University of Kent, Canterbury, United Kingdom
| | - Nigel J. Mason
- Centre for Astrophysics and Planetary Science, School of Physical Sciences, University of Kent, Canterbury, United Kingdom
- Institute for Nuclear Research (Atomki), Debrecen, Hungary
- *Correspondence: Duncan V. Mifsud, ; Péter Herczku, ; Nigel J. Mason,
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133
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Dereli-Bégué H, Pe’er A, Ryde F, Oates SR, Zhang B, Dainotti MG. A wind environment and Lorentz factors of tens explain gamma-ray bursts X-ray plateau. Nat Commun 2022; 13:5611. [PMID: 36153328 PMCID: PMC9509382 DOI: 10.1038/s41467-022-32881-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 08/19/2022] [Indexed: 11/09/2022] Open
Abstract
Gamma-ray bursts (GRBs) are known to have the most relativistic jets, with initial Lorentz factors in the order of a few hundreds. Many GRBs display an early X-ray light-curve plateau, which was not theoretically expected and therefore puzzled the community for many years. Here, we show that this observed signal is naturally obtained within the classical GRB fireball model, provided that the initial Lorentz factor is rather a few tens, and the expansion occurs into a medium-low density wind. The range of Lorentz factors in GRB jets is thus much wider than previously thought and bridges an observational gap between mildly relativistic jets inferred in active galactic nuclei, to highly relativistic jets deduced in few extreme GRBs. Furthermore, long GRB progenitors are either not Wolf-Rayet stars, or the wind properties during the final stellar evolution phase are different than at earlier times. Our model has predictions that can be tested to verify or reject it in the future, such as lack of GeV emission, lack of strong thermal component and long (few seconds) variability during the prompt phase characterizing plateau bursts. The origin of the plateau observed in the early X-ray light curves of gamma ray bursts (GRBs) is debated. Here, the authors show that the observed plateau can be explained within the classical GRB model by considering expanding shell with initial Lorentz factor of a few tens.
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134
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Kappe M, Schiller A, Krasnokutski SA, Ončák M, Scheier P, Cunningham EM. Electronic spectroscopy of cationic adamantane clusters and dehydrogenated adamantane in helium droplets. Phys Chem Chem Phys 2022; 24:23142-23151. [PMID: 36148794 PMCID: PMC9533311 DOI: 10.1039/d2cp03523e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report the first helium-tagged electronic spectra of cationic adamantane clusters, along with its singly, doubly, and triply dehydrogenated analogues embedded in helium droplets. Absorption spectra were measured by recording the evaporation of helium atoms as a function of laser wavelength in the range of 300-2150 nm. Experimental spectra are coupled with simulated spectra obtained from quantum chemical calculations. The spectrum of cationic adamantane agrees with the electronic photodissociation spectrum measured previously, with an additional low-energy absorption at around 1000 nm. The spectra of the dehydrogenated molecules present broad absorptions exclusively in the high-energy region (300-600 nm). For the higher order adamantane dimer and trimer ions, strong absorptions are observed in the low-energy region (900-2150 nm), rationalised by transitions delocalised over two adamantane units.
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Affiliation(s)
- Miriam Kappe
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria.
| | - Arne Schiller
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria.
| | - Serge A Krasnokutski
- Laboratory Astrophysics Group of the MPI for Astronomy at the University of Jena, Helmholtzweg 3, D-07743, Jena, Germany
| | - Milan Ončák
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria.
| | - Paul Scheier
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria.
| | - Ethan M Cunningham
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria.
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135
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Bianchini F, Fabbian G. CMB spectral distortions revisited: A new take on
μ
distortions and primordial non-Gaussianities from FIRAS data. Int J Clin Exp Med 2022. [DOI: 10.1103/physrevd.106.063527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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136
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Gaztanaga E. The Black Hole Universe, Part II. Symmetry (Basel) 2022; 14:1984. [DOI: 10.3390/sym14101984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
In part I of this series, we showed that the observed Universe can be modeled as a local Black Hole of fixed mass M≃6×1022M⊙, without Dark Energy: cosmic acceleration is caused by the Black Hole event horizon rS = 2GM. Here, we propose that such Black Hole Universe (together with smaller primordial Black Holes) could form from the hierarchical free-fall collapse of regular matter. We argue that the singularity could be avoided with a Big Bounce explosion, which results from neutron degeneracy pressure (Pauli exclusion principle). This happens at GeV energies, like in core collapse supernova, well before the collapse reaches Planck energies (1019 GeV). If our Universe formed this way, there is no need for Cosmic Inflation or a singular start (the Big Bang). Nucleosynthesis and recombination follow a hot expansion, as in the standard model, but cosmological measurements (which are free parameters in the standard model) could in principle be predicted from first principles. Part or all of the Dark Matter could be made up of primordial compact objects (Black Holes and Neutron Stars), remnants of the collapse and bounce. This can provide a faster start for galaxy formation. We present a simple prediction to explain the observed value of M≃6×1022M⊙ or equivalently ΩΛ (the fraction of the critical energy density observed today in form of Dark Energy) and the coincidence problem Ωm∼ΩΛ.
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137
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González D, Lema-Saavedra A, Espinosa S, Martínez-Núñez E, Fernández-Ramos A, Canosa A, Ballesteros B, Jiménez E. Reaction of OH radicals with CH 3NH 2 in the gas phase: experimental (11.7-177.5 K) and computed rate coefficients (10-1000 K). Phys Chem Chem Phys 2022; 24:23593-23601. [PMID: 36134502 DOI: 10.1039/d2cp03414j] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nitrogen-bearing molecules, like methylamine (CH3NH2), can be the building blocks of amino acids in the interstellar medium (ISM). At the ultralow temperatures of the ISM, it is important to know its gas-phase reactivity towards interstellar radicals and the products formed. In this work, the kinetics of the OH + CH3NH2 reaction was experimentally and theoretically investigated at low- and high-pressure limits (LPL and HPL) between 10 and 1000 K. Moreover, the CH2NH2 and CH3NH yields were computed in the same temperature range for both pressure regimes. A pulsed CRESU (French acronym for Reaction Kinetics in a Uniform Supersonic Flow) apparatus was employed to determine the rate coefficient, k(T), in the 11.7-177.5 K range. A drastic increase of k(T) when the temperature is lowered was observed in agreement with theoretical calculations, evaluated by the competitive canonical unified statistical (CCUS) theory, below 300 K in the LPL regime. The same trend was observed in the HPL regime below 350 K, but the theoretical k(T) values were higher than the experimental ones. Above 200 K, the calculated rate coefficients are improved with respect to previous computational studies and are in excellent agreement with the experimental literature data. In the LPL, the formation of CH3NH becomes largely dominant below ca. 100 K. Conversely, in the HPL regime, CH2NH2 is the only product below 100 K, whereas CH3NH becomes dominant at 298 K with a branching ratio similar to the one found in the LPL regime (≈70%). At T > 300 K, both reaction channels are competitive independently of the pressure regime.
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Affiliation(s)
- Daniel González
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avda. Camilo José Cela 1b, 13071, Ciudad Real, Spain.
| | - Anxo Lema-Saavedra
- Centro Singular de Investigación en Química Biológica y Materiales Moleculares (CIQUS), Campus Vida, Universidade de Santiago de Compostela, C/Jenaro de la Fuente s/n, 15782, Santiago de Compostela, Spain.
| | - Sara Espinosa
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avda. Camilo José Cela 1b, 13071, Ciudad Real, Spain.
| | - Emilio Martínez-Núñez
- Departamento de Química Física, Facultade de Química, Campus Vida, Universidade de Santiago de Compostela, Avda. das Ciencias s/n, 15782, Santiago de Compostela, Spain
| | - Antonio Fernández-Ramos
- Centro Singular de Investigación en Química Biológica y Materiales Moleculares (CIQUS), Campus Vida, Universidade de Santiago de Compostela, C/Jenaro de la Fuente s/n, 15782, Santiago de Compostela, Spain. .,Departamento de Química Física, Facultade de Química, Campus Vida, Universidade de Santiago de Compostela, Avda. das Ciencias s/n, 15782, Santiago de Compostela, Spain
| | - André Canosa
- CNRS, IPR (Institut de Physique de Rennes)-UMR 6251, Université de Rennes, F-35000 Rennes, France
| | - Bernabé Ballesteros
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avda. Camilo José Cela 1b, 13071, Ciudad Real, Spain. .,Instituto de Investigación en Combustión y Contaminación Atmosférica (ICCA), Universidad de Castilla-La Mancha, Camino de Moledores s/n, 13071, Ciudad Real, Spain
| | - Elena Jiménez
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avda. Camilo José Cela 1b, 13071, Ciudad Real, Spain. .,Instituto de Investigación en Combustión y Contaminación Atmosférica (ICCA), Universidad de Castilla-La Mancha, Camino de Moledores s/n, 13071, Ciudad Real, Spain
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138
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Ibrahim M, Guillemin JC, Chaquin P, Markovits A, Krim L. Formation of CO, CH 4, H 2CO and CH 3CHO through the H 2CCO + H surface reaction under interstellar conditions. Phys Chem Chem Phys 2022; 24:23245-23253. [PMID: 36134501 DOI: 10.1039/d2cp02980d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction of ketene (H2CCO) with hydrogen atoms has been studied under interstellar conditions through two different experimental methods, occurring on the surface and in the bulk of H2CCO ice. We show that ketene interaction with H-atoms at 10 K leads mainly to four reaction products, carbon monoxide (CO), methane (CH4), formaldehyde (H2CO) and acetaldehyde (CH3CHO). A part of these results shows a chemical link between a simple organic molecule such as H2CCO and a complex one such as CH3CHO, through H-addition reactions taking place in dense molecular clouds. The H-addition processes are very often proposed by astrophysical models as mechanisms for the formation of complex organic molecules based on the abundance of species already detected in the interstellar medium. However, the present study shows that the hydrogenation of ketene under non-energetic conditions may also lead efficiently to fragmentation processes and the formation of small species such as CO, CH4 and H2CO, without supplying external energy such as UV photons or high energy particles. Such fragmentation pathways should be included in the astrophysical modeling of H2CCO + H in the molecular clouds of the interstellar medium. To support these results, theoretical calculations have explicitly showed that, under our experimental conditions, H-atom interactions with the CC bond of ketene lead mainly to CH3CHO, CH4 and CO. By investigating the formation and reactivity of the reaction intermediate H3C-CO radical, our calculations demonstrate that the H3C-CO + H reaction evolves through two barrierless pathways to form either CH3CHO or CH4 and CO fragments.
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Affiliation(s)
- Mohamad Ibrahim
- Sorbonne Université, CNRS, De la Molécule aux Nano-Objets: Réactivité, Interactions, Spectroscopies, MONARIS, 75005, Paris, France.
| | - Jean-Claude Guillemin
- Univ Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, ISCR - UMR6226, F-35000 Rennes, France
| | - Patrick Chaquin
- Sorbonne Université, CNRS, Laboratoire de Chimie Théorique, LCT, 75005, Paris, France
| | - Alexis Markovits
- Sorbonne Université, CNRS, Laboratoire de Chimie Théorique, LCT, 75005, Paris, France
| | - Lahouari Krim
- Sorbonne Université, CNRS, De la Molécule aux Nano-Objets: Réactivité, Interactions, Spectroscopies, MONARIS, 75005, Paris, France.
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139
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Wang FY, Zhang GQ, Dai ZG, Cheng KS. Repeating fast radio burst 20201124A originates from a magnetar/Be star binary. Nat Commun 2022; 13:4382. [PMID: 36130932 PMCID: PMC9492772 DOI: 10.1038/s41467-022-31923-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 07/05/2022] [Indexed: 11/21/2022] Open
Abstract
Fast radio bursts (FRBs) are cosmic sources emitting millisecond-duration radio bursts. Although several hundreds FRBs have been discovered, their physical nature and central engine remain unclear. The variations of Faraday rotation measure and dispersion measure, due to local environment, are crucial clues to understanding their physical nature. The recent observations on the rotation measure of FRB 20201124A show a significant variation on a day time scale. Intriguingly, the oscillation of rotation measure supports that the local contribution can change sign, which indicates the magnetic field reversal along the line of sight. Here we present a physical model that explains observed characteristics of FRB 20201124A and proposes that repeating signal comes from a binary system containing a magnetar and a Be star with a decretion disk. When the magnetar approaches the periastron, the propagation of radio waves through the disk of the Be star naturally leads to the observed varying rotation measure, depolarization, large scattering timescale, and Faraday conversion. This study will prompt to search for FRB signals from Be/X-ray binaries. Fast radio bursts (FRBs) are bright millisecond or shorter duration transient events. Here, the authors propose that FRB 20201124A comes from a binary system of a magnetar and a Be star with a decretion disk.
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Affiliation(s)
- F Y Wang
- School of Astronomy and Space Science, Nanjing University, Nanjing, 210093, China. .,Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education, Nanjing, China.
| | - G Q Zhang
- School of Astronomy and Space Science, Nanjing University, Nanjing, 210093, China
| | - Z G Dai
- School of Astronomy and Space Science, Nanjing University, Nanjing, 210093, China.,Department of Astronomy, University of Science and Technology of China, Hefei, 230026, China
| | - K S Cheng
- Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong, China
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140
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Abstract
In the earliest phases of their evolution, stars gain mass through the acquisition of matter from their birth clouds. The widely accepted classical concept of early stellar evolution neglects the details of this accretion phase and assumes the formation of stars with large initial radii that contract gravitationally. In this picture, the common idea is that once the stars begin their fusion processes, they have forgotten their past. By analysing stellar oscillations in recently born stars, we show that the accretion history leaves a potentially detectable imprint on the stars' interior structures. Currently available data from space would allow discriminating between these more realistic accretion scenarios and the classical early stellar evolution models. This opens a window to investigate the interior structures of young pulsating stars that will also be of relevance for related fields, such as stellar oscillations in general and exoplanet studies.
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141
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Xu R, Yang L, Yue Q, Kang K, Li Y, Agartioglu M, An H, Chang J, Chen Y, Cheng J, Dai W, Deng Z, Fang C, Geng X, Gong H, Guo X, Guo Q, He L, He S, Hu J, Huang H, Huang T, Jia H, Jiang X, Li H, Li J, Li J, Li Q, Li R, Li X, Li Y, Liang Y, Liao B, Lin F, Lin S, Liu S, Liu Y, Liu Y, Liu Y, Liu Z, Ma H, Mao Y, Nie Q, Ning J, Pan H, Qi N, Ren J, Ruan X, Saraswat K, Sharma V, She Z, Singh M, Sun T, Tang C, Tang W, Tian Y, Wang G, Wang L, Wang Q, Wang Y, Wang Y, Wong H, Wu S, Wu Y, Xing H, Xu Y, Xue T, Yan Y, Yeh C, Yi N, Yu C, Yu H, Yue J, Zeng M, Zeng Z, Zhang B, Zhang F, Zhang L, Zhang Z, Zhang Z, Zhao K, Zhao M, Zhou J, Zhou Z, Zhu J. Constraints on sub-GeV dark matter boosted by cosmic rays from the CDEX-10 experiment at the China Jinping Underground Laboratory. Int J Clin Exp Med 2022. [DOI: 10.1103/physrevd.106.052008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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142
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Cai RG, Guo ZK, Wang SJ, Yu WW, Zhou Y. No-go guide for late-time solutions to the Hubble tension: Matter perturbations. Int J Clin Exp Med 2022. [DOI: 10.1103/physrevd.106.063519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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143
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Wisdom J, Dbouk R, Militzer B, Hubbard WB, Nimmo F, Downey BG, French RG. Loss of a satellite could explain Saturn’s obliquity and young rings. Science 2022; 377:1285-1289. [DOI: 10.1126/science.abn1234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The origin of Saturn’s ~26.7° obliquity and ~100-million-year-old rings is unknown. The observed rapid outward migration of Saturn’s largest satellite, Titan, could have raised Saturn’s obliquity through a spin-orbit precession resonance with Neptune. We use Cassini data to refine estimates of Saturn’s moment of inertia, finding that it is just outside the range required for the resonance. We propose that Saturn previously had an additional satellite, which we name Chrysalis, that caused Saturn’s obliquity to increase through the Neptune resonance. Destabilization of Chrysalis’s orbit ~100 million years ago can then explain the proximity of the system to the resonance and the formation of the rings through a grazing encounter with Saturn.
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Affiliation(s)
- Jack Wisdom
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Rola Dbouk
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Burkhard Militzer
- Department of Astronomy, University of California, Berkeley, CA 94720, USA
- Department of Earth and Planetary Science, University of California, Berkeley, CA 94720, USA
| | - William B. Hubbard
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721-0092, USA
| | - Francis Nimmo
- Department of Earth and Planetary Sciences, University of California, Santa Cruz, CA 95064, USA
| | - Brynna G. Downey
- Department of Earth and Planetary Sciences, University of California, Santa Cruz, CA 95064, USA
| | - Richard G. French
- Department of Astronomy, Wellesley College, Wellesley, MA 02481, USA
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145
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Kouvatsos N, Lasky PD, Quitzow-James R, Sakellariadou M. Detectability of the gravitational-wave background produced by magnetar giant flares. Int J Clin Exp Med 2022. [DOI: 10.1103/physrevd.106.063007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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146
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Koksbang S. Quantifying effects of inhomogeneities and curvature on gravitational wave standard siren measurements of
H(z). Int J Clin Exp Med 2022. [DOI: 10.1103/physrevd.106.063514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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147
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Sun S, Yang XY, Zhang YL. Pulsar timing residual induced by wideband ultralight dark matter with spin 0,1,2. Int J Clin Exp Med 2022. [DOI: 10.1103/physrevd.106.066006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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148
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Bao SS, Xu QX, Zhang H. Improved analytic solution of black hole superradiance. Int J Clin Exp Med 2022. [DOI: 10.1103/physrevd.106.064016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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149
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Gronowski M, Kołos R. A DFT Study on the Excited Electronic States of Cyanopolyynes: Benchmarks and Applications. Molecules 2022; 27:molecules27185829. [PMID: 36144567 PMCID: PMC9500640 DOI: 10.3390/molecules27185829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 09/01/2022] [Accepted: 09/02/2022] [Indexed: 11/16/2022] Open
Abstract
Highly unsaturated chain molecules are interesting due to their potential application as nanowires and occurrence in interstellar space. Here, we focus on predicting the electronic spectra of polyynic nitriles HC2m+1N (m = 0–13) and dinitriles NC2n+2N (n = 0–14). The results of time-dependent density functional theory (TD-DFT) calculations are compared with the available gas-phase and noble gas matrix experimental data. We assessed the performance of fifteen functionals and five basis sets for reproducing (i) vibrationless electronic excitation energies and (ii) vibrational frequencies in the singlet excited states. We found that the basis sets of at least triple-ζ quality were necessary to describe the long molecules with alternate single and triple bonds. Vibrational frequency scaling factors are similar for the ground and excited states. The benchmarked spectroscopic parameters were shown to be acceptably reproduced with adequately chosen functionals, in particular ωB97X, CAM-B3LYP, B3LYP, B971, and B972. Select functionals were applied to study the electronic excitation of molecules up to HC27N and C30N2. It is demonstrated that optical excitation leads to a shift from the polyyne- to a cumulene-like electronic structure.
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150
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Cruz N, González E, Jovel J. Study of a Viscous ΛWDM Model: Near-Equilibrium Condition, Entropy Production, and Cosmological Constraints. Symmetry (Basel) 2022; 14:1866. [DOI: 10.3390/sym14091866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Extensions to a ΛDM model have been explored in order to face current tensions that occur within its framework, which encompasses broadening the nature of the dark matter (DM) component to include warmness and a non-perfect fluid description. In this paper, we investigated the late-time cosmological evolution of an exact solution recently found in the literature, which describes a viscous warm ΛDM model (ΛWDM) with a DM component that obeys a polytropic equation of state (EoS), which experiences dissipative effects with a bulk viscosity proportional to its energy density, with proportionality constant ξ0. This solution has the particularity of having a very similar behavior to the ΛCDM model for small values of ξ0, evolving also to a de Sitter type expansion in the very far future. We explore firstly the thermodynamic consistences of this solution in the framework of Eckart’s theory of non-perfect fluids, focusing on the fulfillment of the two following conditions: (i) the near-equilibrium condition and (ii) the positiveness of the entropy production. We explore the range of parameters of the model that allow to fulfill these two conditions at the same time, finding that a viscous WDM component is compatible with both ones, being in this sense, a viable model from the thermodynamic point of view. Furthermore, we constrained the free parameters of the model with the observational data coming from supernovae Ia (SNe Ia) and the observational Hubble parameter data (OHD), using these thermodynamics analyses to define the best priors for the cosmological parameters related to the warmness and the dissipation of the DM, showing that this viscous ΛWDM model can describe the combined SNe Ia+OHD data in the same way as the ΛCDM model. The cosmological constraint at 3σ CL gives us an upper limit on the bulk viscous constant of order ξ0∼106 Pa·s, which is in agreement with some previous investigations. Our results support that the inclusion of a dissipative WDM, as an extension of the standard cosmological model, leads to a both thermodynamically consistent and properly fitted cosmological evolution.
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