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Massahi S, Christensen FE, Ferreira DDM, Svendsen S, Henriksen PL, Vu LM, Gellert NC, Jegers AS, Shortt B, Bavdaz M, Ferreira I, Collon M, Landgraf B, Girou D, Sokolov A, Schoenberger W. Investigation of boron carbide and iridium thin films, an enabling technology for future x-ray telescopes. Appl Opt 2020; 59:10902-10911. [PMID: 33361911 DOI: 10.1364/ao.409453] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 11/06/2020] [Indexed: 06/12/2023]
Abstract
We present an experimental examination of iridium and boron carbide thin-film coatings for the purpose of fabricating x-ray optics. We use a combination of x-ray reflectometry and x-ray photoelectron spectroscopy to model the structure, composition, density, thickness, and micro-roughness of the thin films. We demonstrate in our analyses how the two characterization techniques are complementary, and from this we derive that an overlayer originating from atmospheric contamination with a thickness between 1.0-1.6 nm is present on the surface. The magnetron sputtered iridium films are measured to have a density of 22.4g/cm3. The boron carbide film exhibits a change in chemical composition in the top ∼2nm of the film surface when exposed to the ambient atmosphere. The chemical reaction occurring on the surface is due to an incorporation of oxygen and hydrogen present in the ambient atmosphere. Lastly, we present a correlation between the absorption edges and the emission lines exhibited by the thin films in an energy range from 50-800 eV and the impact on the reflectivity performance due to contamination in thin films.
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Annuar A, Gandhi P, Alexander DM, Lansbury GB, Arévalo P, Ballantyne DR, Baloković M, Bauer FE, Boggs SE, Brandt WN, Brightman M, Christensen FE, Craig WW, Moro AD, Hailey CJ, Harrison FA, Hickox RC, Matt G, Puccetti S, Ricci C, Rigby JR, Stern D, Walton DJ, Zappacosta L, Zhang W. NuSTAROBSERVATIONS OF THE COMPTON-THICK ACTIVE GALACTIC NUCLEUS AND ULTRALUMINOUS X-RAY SOURCE CANDIDATE IN NGC 5643. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/0004-637x/815/1/36] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Keck ML, Brenneman LW, Ballantyne DR, Bauer F, Boggs SE, Christensen FE, Craig WW, Dauser T, Elvis M, Fabian AC, Fuerst F, García J, Grefenstette BW, Hailey CJ, Harrison FA, Madejski G, Marinucci A, Matt G, Reynolds CS, Stern D, Walton DJ, Zoghbi A. NUSTARANDSUZAKUX-RAY SPECTROSCOPY OF NGC 4151: EVIDENCE FOR REFLECTION FROM THE INNER ACCRETION DISK. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/0004-637x/806/2/149] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Boggs SE, Harrison FA, Miyasaka H, Grefenstette BW, Zoglauer A, Fryer CL, Reynolds SP, Alexander DM, An H, Barret D, Christensen FE, Craig WW, Forster K, Giommi P, Hailey CJ, Hornstrup A, Kitaguchi T, Koglin JE, Madsen KK, Mao PH, Mori K, Perri M, Pivovaroff MJ, Puccetti S, Rana V, Stern D, Westergaard NJ, Zhang WW. 44
Ti gamma-ray emission lines from SN1987A reveal an asymmetric explosion. Science 2015; 348:670-1. [DOI: 10.1126/science.aaa2259] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- S. E. Boggs
- Space Sciences Laboratory, University of California, Berkeley, CA 94720, USA
| | - F. A. Harrison
- Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA
| | - H. Miyasaka
- Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA
| | - B. W. Grefenstette
- Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA
| | - A. Zoglauer
- Space Sciences Laboratory, University of California, Berkeley, CA 94720, USA
| | - C. L. Fryer
- CCS-2, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - S. P. Reynolds
- Physics Department, NC State University, Raleigh, NC 27695, USA
| | - D. M. Alexander
- Department of Physics, Durham University, Durham DH1 3LE, UK
| | - H. An
- Department of Physics, McGill University, Rutherford Physics Building, Montreal, Quebec H3A 2T8, Canada
| | - D. Barret
- Université de Toulouse, UPS-OMP, IRAP, Toulouse, France
- CNRS, Institut de Recherche en Astrophysique et Planétologie, 9 Av. colonel Roche, BP 44346, F-31028 Toulouse Cedex 4, France
| | - F. E. Christensen
- DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby, Denmark
| | - W. W. Craig
- Space Sciences Laboratory, University of California, Berkeley, CA 94720, USA
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - K. Forster
- Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA
| | - P. Giommi
- Agenzia Spaziale Italiana (ASI) Science Data Center, Via del Politecnico snc I-00133, Roma, Italy
| | - C. J. Hailey
- Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027, USA
| | - A. Hornstrup
- DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby, Denmark
| | - T. Kitaguchi
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - J. E. Koglin
- Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - K. K. Madsen
- Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA
| | - P. H. Mao
- Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA
| | - K. Mori
- Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027, USA
| | - M. Perri
- Agenzia Spaziale Italiana (ASI) Science Data Center, Via del Politecnico snc I-00133, Roma, Italy
- INAF – Osservatorio Astronomico di Roma, via di Frascati 33, I-00040 Monteporzio, Italy
| | - M. J. Pivovaroff
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - S. Puccetti
- Agenzia Spaziale Italiana (ASI) Science Data Center, Via del Politecnico snc I-00133, Roma, Italy
- INAF – Osservatorio Astronomico di Roma, via di Frascati 33, I-00040 Monteporzio, Italy
| | - V. Rana
- Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA
| | - D. Stern
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - N. J. Westergaard
- DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby, Denmark
| | - W. W. Zhang
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
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Nardini E, Reeves JN, Gofford J, Harrison FA, Risaliti G, Braito V, Costa MT, Matzeu GA, Walton DJ, Behar E, Boggs SE, Christensen FE, Craig WW, Hailey CJ, Matt G, Miller JM, O'Brien PT, Stern D, Turner TJ, Ward MJ. Galaxy evolution. Black hole feedback in the luminous quasar PDS 456. Science 2015; 347:860-3. [PMID: 25700515 DOI: 10.1126/science.1259202] [Citation(s) in RCA: 154] [Impact Index Per Article: 17.1] [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 evolution of galaxies is connected to the growth of supermassive black holes in their centers. During the quasar phase, a huge luminosity is released as matter falls onto the black hole, and radiation-driven winds can transfer most of this energy back to the host galaxy. Over five different epochs, we detected the signatures of a nearly spherical stream of highly ionized gas in the broadband x-ray spectra of the luminous quasar PDS 456. This persistent wind is expelled at relativistic speeds from the inner accretion disk, and its wide aperture suggests an effective coupling with the ambient gas. The outflow's kinetic power larger than 10(46) ergs per second is enough to provide the feedback required by models of black hole and host galaxy coevolution.
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Affiliation(s)
- E Nardini
- Astrophysics Group, School of Physical and Geographical Sciences, Keele University, Keele, Staffordshire ST5 5BG, UK.
| | - J N Reeves
- Astrophysics Group, School of Physical and Geographical Sciences, Keele University, Keele, Staffordshire ST5 5BG, UK. Center for Space Science and Technology, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - J Gofford
- Astrophysics Group, School of Physical and Geographical Sciences, Keele University, Keele, Staffordshire ST5 5BG, UK. Center for Space Science and Technology, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - F A Harrison
- Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA
| | - G Risaliti
- Istituto Nazionale di Astrofisica, Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, I-50125 Firenze, Italy. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
| | - V Braito
- INAF, Osservatorio Astronomico di Brera, Via Bianchi 46, I-23807 Merate (LC), Italy
| | - M T Costa
- Astrophysics Group, School of Physical and Geographical Sciences, Keele University, Keele, Staffordshire ST5 5BG, UK
| | - G A Matzeu
- Astrophysics Group, School of Physical and Geographical Sciences, Keele University, Keele, Staffordshire ST5 5BG, UK
| | - D J Walton
- Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - E Behar
- Department of Physics, Technion, Haifa 32000, Israel
| | - S E Boggs
- Space Science Laboratory, University of California, Berkeley, CA 94720, USA
| | - F E Christensen
- Danmarks Tekniske Universitet Space-National Space Institute, Technical University of Denmark, Elektrovej 327, 2800 Lyngby, Denmark
| | - W W Craig
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - C J Hailey
- Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027, USA
| | - G Matt
- Dipartimento di Matematica e Fisica, Università degli Studi Roma Tre, Via della Vasca Navale 84, I-00146 Roma, Italy
| | - J M Miller
- Department of Astronomy, University of Michigan, Ann Arbor, MI 48109, USA
| | - P T O'Brien
- Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH, UK
| | - D Stern
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - T J Turner
- Physics Department, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA. Eureka Scientific Inc., 2452 Delmer Street Suite 100, Oakland, CA 94602, USA
| | - M J Ward
- Department of Physics, University of Durham, South Road, Durham DH1 3LE, UK
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Walton DJ, Harrison FA, Bachetti M, Barret D, Boggs SE, Christensen FE, Craig WW, Fuerst F, Grefenstette BW, Hailey CJ, Madsen KK, Middleton MJ, Rana V, Roberts TP, Stern D, Sutton AD, Webb N, Zhang W. NUSTARANDXMM-NEWTONOBSERVATIONS OF THE EXTREME ULTRALUMINOUS X-RAY SOURCE NGC 5907 ULX1: A VANISHING ACT. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/0004-637x/799/2/122] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Baloković M, Comastri A, Harrison FA, Alexander DM, Ballantyne DR, Bauer FE, Boggs SE, Brandt WN, Brightman M, Christensen FE, Craig WW, Moro AD, Gandhi P, Hailey CJ, Koss M, Lansbury GB, Luo B, Madejski GM, Marinucci A, Matt G, Markwardt CB, Puccetti S, Reynolds CS, Risaliti G, Rivers E, Stern D, Walton DJ, Zhang WW. THENuSTARVIEW OF NEARBY COMPTON-THICK ACTIVE GALACTIC NUCLEI: THE CASES OF NGC 424, NGC 1320, AND IC 2560. ACTA ACUST UNITED AC 2014. [DOI: 10.1088/0004-637x/794/2/111] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Luo B, Brandt WN, Alexander DM, Stern D, Teng SH, Arévalo P, Bauer FE, Boggs SE, Christensen FE, Comastri A, Craig WW, Farrah D, Gandhi P, Hailey CJ, Harrison FA, Koss M, Ogle P, Puccetti S, Saez C, Scott AE, Walton DJ, Zhang WW. WEAK HARD X-RAY EMISSION FROM BROAD ABSORPTION LINE QUASARS: EVIDENCE FOR INTRINSIC X-RAY WEAKNESS. ACTA ACUST UNITED AC 2014. [DOI: 10.1088/0004-637x/794/1/70] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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9
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Walton DJ, Harrison FA, Grefenstette BW, Miller JM, Bachetti M, Barret D, Boggs SE, Christensen FE, Craig WW, Fabian AC, Fuerst F, Hailey CJ, Madsen KK, Parker ML, Ptak A, Rana V, Stern D, Webb N, Zhang WW. BROADBAND X-RAY SPECTRA OF THE ULTRALUMINOUS X-RAY SOURCE HOLMBERG IX X-1 OBSERVED WITHNuSTAR,XMM-NEWTON,ANDSUZAKU. ACTA ACUST UNITED AC 2014. [DOI: 10.1088/0004-637x/793/1/21] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Wik DR, Hornstrup A, Molendi S, Madejski G, Harrison FA, Zoglauer A, Grefenstette BW, Gastaldello F, Madsen KK, Westergaard NJ, Ferreira DDM, Kitaguchi T, Pedersen K, Boggs SE, Christensen FE, Craig WW, Hailey CJ, Stern D, Zhang WW. NuSTAROBSERVATIONS OF THE BULLET CLUSTER: CONSTRAINTS ON INVERSE COMPTON EMISSION. ACTA ACUST UNITED AC 2014. [DOI: 10.1088/0004-637x/792/1/48] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Grefenstette BW, Harrison FA, Boggs SE, Reynolds SP, Fryer CL, Madsen KK, Wik DR, Zoglauer A, Ellinger CI, Alexander DM, An H, Barret D, Christensen FE, Craig WW, Forster K, Giommi P, Hailey CJ, Hornstrup A, Kaspi VM, Kitaguchi T, Koglin JE, Mao PH, Miyasaka H, Mori K, Perri M, Pivovaroff MJ, Puccetti S, Rana V, Stern D, Westergaard NJ, Zhang WW. Asymmetries in core-collapse supernovae from maps of radioactive 44Ti in Cassiopeia A. Nature 2014; 506:339-42. [PMID: 24553239 DOI: 10.1038/nature12997] [Citation(s) in RCA: 180] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Accepted: 12/13/2013] [Indexed: 11/09/2022]
Abstract
Asymmetry is required by most numerical simulations of stellar core-collapse explosions, but the form it takes differs significantly among models. The spatial distribution of radioactive (44)Ti, synthesized in an exploding star near the boundary between material falling back onto the collapsing core and that ejected into the surrounding medium, directly probes the explosion asymmetries. Cassiopeia A is a young, nearby, core-collapse remnant from which (44)Ti emission has previously been detected but not imaged. Asymmetries in the explosion have been indirectly inferred from a high ratio of observed (44)Ti emission to estimated (56)Ni emission, from optical light echoes, and from jet-like features seen in the X-ray and optical ejecta. Here we report spatial maps and spectral properties of the (44)Ti in Cassiopeia A. This may explain the unexpected lack of correlation between the (44)Ti and iron X-ray emission, the latter being visible only in shock-heated material. The observed spatial distribution rules out symmetric explosions even with a high level of convective mixing, as well as highly asymmetric bipolar explosions resulting from a fast-rotating progenitor. Instead, these observations provide strong evidence for the development of low-mode convective instabilities in core-collapse supernovae.
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Affiliation(s)
- B W Grefenstette
- Cahill Center for Astrophysics, 1216 East California Boulevard, California Institute of Technology, Pasadena, California 91125, USA
| | - F A Harrison
- Cahill Center for Astrophysics, 1216 East California Boulevard, California Institute of Technology, Pasadena, California 91125, USA
| | - S E Boggs
- Space Sciences Laboratory, University of California, Berkeley, California 94720, USA
| | - S P Reynolds
- Physics Department, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - C L Fryer
- CCS-2, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - K K Madsen
- Cahill Center for Astrophysics, 1216 East California Boulevard, California Institute of Technology, Pasadena, California 91125, USA
| | - D R Wik
- NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - A Zoglauer
- Space Sciences Laboratory, University of California, Berkeley, California 94720, USA
| | - C I Ellinger
- Department of Physics, University of Texas at Arlington, Arlington, Texas 76019, USA
| | - D M Alexander
- Department of Physics, Durham University, Durham DH1 3LE, UK
| | - H An
- Department of Physics, McGill University, Rutherford Physics Building, Montreal, Quebec H3A 2T8, Canada
| | - D Barret
- 1] Université de Toulouse, UPS-OMP, IRAP, 9 Avenue du Colonel Roche, BP 44346, 31028 Toulouse Cedex 4, France [2] CNRS, Institut de Recherche en Astrophysique et Planétologie, 9 Avenue colonel Roche, BP 44346, F-31028 Toulouse Cedex 4, France
| | - F E Christensen
- DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby, Denmark
| | - W W Craig
- 1] Space Sciences Laboratory, University of California, Berkeley, California 94720, USA [2] Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - K Forster
- Cahill Center for Astrophysics, 1216 East California Boulevard, California Institute of Technology, Pasadena, California 91125, USA
| | - P Giommi
- Agenzia Spaziale Italiana (ASI) Science Data Center, Via del Politecnico snc, I-00133 Roma, Italy
| | - C J Hailey
- Columbia Astrophysics Laboratory, Columbia University, New York, New York 10027, USA
| | - A Hornstrup
- DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby, Denmark
| | - V M Kaspi
- Department of Physics, McGill University, Rutherford Physics Building, Montreal, Quebec H3A 2T8, Canada
| | - T Kitaguchi
- RIKEN, Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - J E Koglin
- Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - P H Mao
- Cahill Center for Astrophysics, 1216 East California Boulevard, California Institute of Technology, Pasadena, California 91125, USA
| | - H Miyasaka
- Cahill Center for Astrophysics, 1216 East California Boulevard, California Institute of Technology, Pasadena, California 91125, USA
| | - K Mori
- Columbia Astrophysics Laboratory, Columbia University, New York, New York 10027, USA
| | - M Perri
- 1] Agenzia Spaziale Italiana (ASI) Science Data Center, Via del Politecnico snc, I-00133 Roma, Italy [2] INAF - Osservatorio Astronomico di Roma, via di Frascati 33, I-00040 Monteporzio, Italy
| | - M J Pivovaroff
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - S Puccetti
- 1] Agenzia Spaziale Italiana (ASI) Science Data Center, Via del Politecnico snc, I-00133 Roma, Italy [2] INAF - Osservatorio Astronomico di Roma, via di Frascati 33, I-00040 Monteporzio, Italy
| | - V Rana
- Cahill Center for Astrophysics, 1216 East California Boulevard, California Institute of Technology, Pasadena, California 91125, USA
| | - D Stern
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA
| | - N J Westergaard
- DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby, Denmark
| | - W W Zhang
- NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
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12
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Baloković M, Ajello M, Blandford RD, Boggs SE, Borracci F, Chiang J, Christensen FE, Craig WW, Forster K, Furniss A, Fürst F, Ghisellini G, Giebels B, Giommi P, Grefenstette BW, Hailey CJ, Harrison FA, Hayashida M, Humensky B, Inoue Y, Koglin JE, Krawczynski H, Madejski GM, Madsen KK, Meier DL, Nelson T, Ogle P, Paneque D, Perri M, Puccetti S, Reynolds CS, Sbarrato T, Stern D, Tagliaferri G, Urry CM, Wehrle AE, Zhang WW. First Results fromNuSTARObservations of Mkn 421. EPJ Web of Conferences 2013. [DOI: 10.1051/epjconf/20136104013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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13
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Risaliti G, Harrison FA, Madsen KK, Walton DJ, Boggs SE, Christensen FE, Craig WW, Grefenstette BW, Hailey CJ, Nardini E, Stern D, Zhang WW. A rapidly spinning supermassive black hole at the centre of NGC 1365. Nature 2013; 494:449-51. [PMID: 23446416 DOI: 10.1038/nature11938] [Citation(s) in RCA: 222] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 01/16/2013] [Indexed: 11/09/2022]
Abstract
Broad X-ray emission lines from neutral and partially ionized iron observed in active galaxies have been interpreted as fluorescence produced by the reflection of hard X-rays off the inner edge of an accretion disk. In this model, line broadening and distortion result from rapid rotation and relativistic effects near the black hole, the line shape being sensitive to its spin. Alternative models in which the distortions result from absorption by intervening structures provide an equally good description of the data, and there has been no general agreement on which is correct. Recent claims that the black hole (2 × 10(6) solar masses) at the centre of the galaxy NGC 1365 is rotating at close to its maximum possible speed rest on the assumption of relativistic reflection. Here we report X-ray observations of NGC 1365 that reveal the relativistic disk features through broadened Fe-line emission and an associated Compton scattering excess of 10-30 kiloelectronvolts. Using temporal and spectral analyses, we disentangle continuum changes due to time-variable absorption from reflection, which we find arises from a region within 2.5 gravitational radii of the rapidly spinning black hole. Absorption-dominated models that do not include relativistic disk reflection can be ruled out both statistically and on physical grounds.
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Affiliation(s)
- G Risaliti
- INAF-Osservatoria Astrofisico di Arcetri, Largo Enrico Fermi 5, 50125 Firenze, Italy.
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14
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Mao PH, Harrison FA, Windt DL, Christensen FE. Optimization of graded multilayer designs for astronomical X-ray telescopes. Appl Opt 1999; 38:4766-4775. [PMID: 18323965 DOI: 10.1364/ao.38.004766] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We developed a systematic method for optimizing the design of depth-graded multilayers for astronomical hard-x-ray and soft-gamma-ray telescopes based on the instrument's bandpass and the field of view. We apply these methods to the design of the conical-approximation Wolter I optics employed by the balloon-borne High Energy Focusing Telescope, using W/Si as the multilayer materials. In addition, we present optimized performance calculations of mirrors, using other material pairs that are capable of extending performance to photon energies above the W K-absorption edge (69.5 keV), including Pt/C, Ni/C, Cu/Si, and Mo/Si.
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Affiliation(s)
- P H Mao
- Department of Physics, California Institute of Technology, MC 220-47, Pasadena, California 91125, USA.
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15
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Joensen KD, Voutov P, Szentgyorgyi A, Roll J, Gorenstein P, Høghøj P, Christensen FE. Design of grazing-incidence multilayer supermirrors for hard-x-ray reflectors. Appl Opt 1995; 34:7935-7944. [PMID: 21068887 DOI: 10.1364/ao.34.007935] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Extremely broadband grazing-incidence multilayers for hard-x-ray reflection can be obtained by a gradual change of the layer thicknesses down through the structure. Existing approaches for designing similar neutron optics, called supermirrors, are shown to provide respectable performance when applied to x-ray multilayers. However, none of these approaches consider the effects of imperfect layer interfaces and absorption in the overlying layers. Adaptations of neutron designs that take these effects into account are presented, and a thorough analysis of two specific applications (a single hard-x-ray reflector and a hard-x-ray telescope) shows that an improved performance can be obtained. A multilayer whose bilayer thicknesses are given by a power law expression is found to provide the best solution; however, it is only slightly better than some of the adapted neutron designs.
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Palmari J, Rasigni M, Rasigni G, Christensen FE, Hornstrup A, Schnopper HW. Electron micrography and x-ray study of dip-lacquered LiF (220). Appl Opt 1991; 30:3667-3672. [PMID: 20706443 DOI: 10.1364/ao.30.003667] [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] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
It has been proposed to use the 220 reflection of LiF with a multilayer deposited upon the top for simultaneous spectroscopy near Fe-k and O-k and below the C-k absorption edge (284 eV) in x-ray astronomy. We demonstrate that a substantial reduction of surface roughness is obtained by dip lacquering state-of-the-art polished LiF(220) surfaces. Using a microdensitometer analysis of electron micrographs of surface replicas and x-ray reflection, we have measured approximately 10-A rms roughness of Au-coated dip-lacquered LiF(220) crystals, as opposed to approximately 60 A measured on the bare LiF(220) crystal surface.
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Puik EJ, van der Wiel MJ, Lambooy P, Verhoeven J, Christensen FE, Padmore HA. Characterization of a Multilayer Coated Laminar Reflection Grating at λ = 0.154 nm. J Xray Sci Technol 1991; 3:19-34. [PMID: 21307434 DOI: 10.3233/xst-1991-3103] [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] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A laminar grating of 1200 1/mm was coated with an x-ray reflecting multilayer coating. The multilayer coating consisted of 41 alternating layers of ReW and C having a period of 2.3 nm. In this paper we report on diffraction measurements of the coated grating at the CuKα emission line. We describe its reflection behavior using a simple theoretical model and derive two diffraction conditions, corresponding to the grating relation and the Bragg law, for which peak intensities are to be observed. We find that grating order efficiencies are modulated by the multilayer reflection.
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Affiliation(s)
- E J Puik
- Association Euratom-FOM, FOM Institute for Plasma Physics Rijnhuizen, P.O. Box 1207, 3430 BE Nieuwegein, The Netherlands
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Christensen FE, Shou-Hua Z, Hornstrup A, Schnopper HW, Plag P, Wood J. X-Ray Study of State-of-the-Art Small (d-Spacing W/B4C Multilayers. J Xray Sci Technol 1991; 3:1-13. [PMID: 21307432 DOI: 10.3233/xst-1991-3101] [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] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Two small d-spacing W/B4C multilayers have been studied at three different x-ray energies CuKα1, AlKα, and FeLα. Measurements of total reflection, specular and mosaic Bragg reflection, and high resolution studies were made at Cu Kα1. Multilayer parameters are deduced from the data and the perfection of the multilayer structure is evaluated by Comparison with model Calculations.
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Christensen FE, Hornstrup A, Frederiksen P, Grundsøe P, Henrichsen S, Jacobsen E, Jonasson P, Madsen MM, Nilsson C, Schnopper HW, Westergaard NJ, Orup P. Studies of multilayers and thin-foil x-ray mirrors using a soft x-ray diffractometer. J Xray Sci Technol 1990; 2:81-94. [PMID: 21307422 DOI: 10.3233/xst-1990-2201] [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] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A versatile x-ray diffractometer is described in detail. Two applications to the study of x-ray optical elements are presented. The first is a Bragg reflection study of state-of-the-art multilayers deposited both on conventional Si-wafer substrates and on superpolished substrates such as fused quartz and electroless nickel. These data are compared to data previously obtained at FeKα. The second study is a reflectivity and scattering study of various thin-foil x-ray reflectors proposed for up-coming x-ray satellite missions. All the data have been obtained at MgKα = 1.2536 keV.
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Affiliation(s)
- F E Christensen
- Danish Space Research Institute, Gl. Lundtoftevej 7, DK-2800 Lyngby, Denmark
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Alehyane N, Arbaoui M, Barchewitz R, André JM, Christensen FE, Hornstrup A, Palmari J, Rasigni M, Rivoira R, Rasigni G. Extreme UV and x-ray scattering measurements from a rough LiF crystal surface characterized by electron micrography. Appl Opt 1989; 28:1763-1772. [PMID: 20548740 DOI: 10.1364/ao.28.001763] [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] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
XUV and x-ray scattering by a LiF crystal is measured. The angular distribution of the scattered radiation (ADSR) reveals characteristic features, side peaks or asymmetry. The surface of the sample is statistically characterized by a microdensitometer analysis of electron micrographs resolving the short spatial wavelengths of the surface roughness. This analysis shows that the surface has a large microroughness with an autocovariance function which is Gaussian in its initial portion. The first-order perturbation vector theory of the roughness-induced scattering leads to an interpretation of the ADSR features in terms of the modulation of the surface power spectral density function associated with the microroughness by an optical factor. The possibility of obtaining short scale roughness characterization from XUV or x-ray measurements is discussed.
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Christensen FE, Hornstrup A, Schnopper HW. Surface correlation function analysis of high resolution scattering data from mirrored surfaces obtained using a triple-axis x-ray diffractometer. Appl Opt 1988; 27:1548-1557. [PMID: 20531612 DOI: 10.1364/ao.27.001548] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Within various x-ray programs there exists a need for a detailed investigation of the surface roughness of mirrored surfaces over a wide spatial wavelength bandwidth, ranging from large scale figure error to micro roughness. A number of methods exist to measure the surface roughness. Common to all methods is that they are bandwidth-limited. A crucial point in the analysis of data is, therefore, to specify accurately the wavelength bandwidth limitation and to determine the surface autocorrelation function within this bandwidth. We present a number of scattering measurements obtained using a triple-axis perfect-crystal x-ray diffractometer and the results of an autocorrelation function analysis. Furthermore, we present some measurements of integrated reflectivity, which we believe provide evidence for microroughness in the range from a few angstroms to tens of microns.
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Christensen FE, Singh KP, Westergaard NJ, Schnopper HW. Measurements of mosaicity and perfection of crystallites in commercially available crystals using a 4-axis perfect-crystal x-ray diffractometer. Appl Opt 1987; 26:235-240. [PMID: 20454118 DOI: 10.1364/ao.26.000235] [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] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Measurements of mosaicity and the intrinsic scattering from individual crystallites of commercially available crystals are presented. The set of crystals investigated has been proposed to be used as the energy dispersive element in a high resolution Bragg spectrometer for x-ray astronomy. The measurements reveal a high degree of perfection of the crystallites, even in the presence of considerable mosaicity. This is encouraging with relation to an eventual use of the crystals in a high resolution Bragg spectrometer for x-ray astronomy. The measurements were performed using a novel four-crystal x-ray diffractometer. The resolution properties of this diffractometer are discussed in detail and compared with more conventional three-crystal and twocrystal x-ray diffractometers.
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Byrnak BP, Christensen FE, Westergaard NJ, Schnopper HW. Doubly curved imaging Bragg crystal spectrometer for x-ray astronomy. Appl Opt 1985; 24:2543. [PMID: 18223918 DOI: 10.1364/ao.24.002543] [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: 05/25/2023]
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