13 results on '"Boggs, S.E."'
Search Results
2. Antideuteron based dark matter search with GAPS: Current progress and future prospects
- Author
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Hailey, C.J., Aramaki, T., Boggs, S.E., Doetinchem, P.v., Fuke, H., Gahbauer, F., Koglin, J.E., Madden, N., Mognet, S.A.I., Ong, R., Yoshida, T., Zhang, T., and Zweerink, J.A.
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- 2013
- Full Text
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3. An ultraluminous X-ray source powered by an accreting neutron star
- Author
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Bachetti, M., Harrison, F.A., Walton, D.J., Grefenstette, B.W., Chakrabarty, D., Furst, F., Barret, D., Beloborodov, A., Boggs, S.E., Christensen, F.E., Craig, W.W., Fabian, A.C., Hailey, C.J., Hornschemeier, A., Kaspi, V., Kulkarni, S.R., Maccarone, T., Miller, J.M., Rana, V., Stern, D., Tendulkar, S.P., Tomsick, J., Webb, N.A., and Zhang, W.W.
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Galaxies -- Observations ,Galactic center -- Observations ,Environmental issues ,Science and technology ,Zoology and wildlife conservation - Abstract
The majority of ultraluminous X-ray sources are point sources that are spatially offset from the nuclei of nearby galaxies and whose X-ray luminosities exceed the theoretical maximum for spherical infall (the Eddington limit) onto stellar-mass black holes (1,2). Their X-ray luminosities in the 0.5-10 kiloelectronvolt energy band range from [10.sup.39] to [10.sup.41] ergs per second (3). Because higher masses imply less extreme ratios of the luminosity to the isotropic Eddington limit, theoretical models have focused on black hole rather than neutron star systems (1,2). The most challenging sources to explain are those at the luminous end of the range (more than [10.sub.40] ergs per second), which require black hole masses of 50-100 times the solar value or significant departures from the standard thin disk accretion that powers bright Galactic X-ray binaries, or both. Here we report broadband X-ray observations of the nuclear region of the galaxy M82 that reveal pulsations with an average period of 1.37 seconds and a 2.5-day sinusoidal modulation. The pulsations result from the rotation of a magnetized neutron star, and the modulation arises from its binary orbit. The pulsed flux alone corresponds to an X-ray luminosity in the 3-30 kiloelectronvolt range of 4.9 x [10.sup.39] ergs per second. The pulsating source is spatially coincident with a variable source (4) that can reach an X-ray luminosity in the 0.3-10 kiloelectronvolt range of 1.8 x [10.sup.40] ergs per second (1). This association implies a luminosity of about 100 times the Eddington limit for a 1.4-solar-mass object, or more than ten times brighter than any known accreting pulsar. This implies that neutron stars may not be rare in the ultraluminous X-ray population, and it challenges physical models for the accretion of matter onto magnetized compact objects., The brightest accretion-powered X-ray pulsars, A0538-66 (5), SMCX-1 (6) and GRO J1744-28 (7), are variable, with reported X-ray luminosities up to [L.sub.X] (2-20 keV) ≅ [10.sup.39] erg [s.sup.-1], which are [...]
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- 2014
4. Asymmetries in core-collapse supernovae from maps of radioactive [sup.44]Ti in Cassiopeia A
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Grefenstette, B.W., Harrison, F.A., Boggs, S.E., Reynolds, S.P., Fryer, C.L., Madsen, K.K., Wik, D.R., Zoglauer, A., Ellinger, C.I., Alexander, D.M., An, H., Barret, D., Christensen, F.E., Craig, W.W., Forster, K., Giommi, P., Hailey, C.J., Hornstrup, A., Kaspi, V.M., Kitaguchi, T., Koglin, J.E., Mao, P.H., Miyasaka, H., Mori, K., Perri, M., Pivovaroff, M.J., Puccetti, S., Rana, V., Stern, D., Westergaard, N.J., and Zhang, W.W.
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Supernovae -- Natural history ,Environmental issues ,Science and technology ,Zoology and wildlife conservation - 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 [sup.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 (1), directly probes the explosion asymmetries. Cassiopeia A is a young (2), nearby (3), core-collapse (4) remnant from which [sup.44]Ti emission has previously been detected (5-8) but not imaged. Asymmetries in the explosion have been indirectly inferred from a high ratio of observed [sup.44]Ti emission to estimated [sup.56]Ni emission (9), from optical light echoes (10), and from jet-like features seen in the X-ray (11) and optical (12) ejecta. Here we report spatial maps and spectral properties of the [sup.44]Ti in Cassiopeia A. This may explain the unexpected lack of correlation between the [sup.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., Titanium-44 is produced in Si burning in the innermost regions of the material ejected in core-collapse supernovae, in the same processes that produce Fe and [56.sup]Ni (ref. 13). The decay [...]
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- 2014
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5. Antideuterons as an indirect dark matter signature: Si(Li) detector development and a GAPS balloon mission
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Aramaki, T., Boggs, S.E., Craig, W.W., Fuke, H., Gahbauer, F., Hailey, C.J., Koglin, J.E., Madden, N., Mori, K., Ong, R.A., and Yoshida, T.
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- 2010
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6. The Nature of the Torus in the Heavily Obscured AGN Markarian 3: an X-Ray Study
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Guainazzi, M, Risaliti, G, Awaki, H, Arevalo, P, Bauer, F. E, Bianchi, S, Boggs, S.E, Brandt, W. N, Brightman, M, Christensen, F. E, Craig, W. W, Forster, K, Hailey, C. J, Harrison, F, Koss, M, Longinotti, A, Markwardt, C. B, Marinucci, A, Matt, G, Reynolds, C. S, Ricci, C, Stern, D, Svoboda, J, Walton, D, and Zhang, W
- Subjects
Astrophysics - Abstract
In this paper, we report the results of an X-ray monitoring campaign on the heavily obscured Seyfert galaxy, Markarian 3, carried out between the fall of 2014 and the spring of 2015 with NuSTAR, Suzaku and XMMNewton. The hard X-ray spectrum of Markarian 3 is variable on all the time-scales probed by our campaign, down to a few days. The observed continuum variability is due to an intrinsically variable primary continuum seen in transmission through a large, but still Compton-thin column density (N(sub H) approx. 0.8-1.1 x 10(exp 24)/sq cm). If arranged in a spherical-toroidal geometry, the Compton scattering matter has an opening angle approx. 66deg, and is seen at a grazing angle through its upper rim (inclination angle approx. 70deg). We report a possible occultation event during the 2014 campaign. If the torus is constituted by a system of clouds sharing the same column density, this event allows us to constrain their number (17 +/- 5) and individual column density, [approx. (4.9 +/- 1.5) x 10(exp 22)/ sq cm]. The comparison of IR and X-ray spectroscopic results with state-of-the art torus models suggests that at least two-thirds of the X-ray obscuring gas volume might be located within the dust sublimation radius. We report also the discovery of an ionized absorber, characterized by variable resonant absorption lines due to He- and H-like iron. This discovery lends support to the idea that moderate column density absorbers could be due to clouds evaporated at the outer surface of the torus, possibly accelerated by the radiation pressure due to the central AGN emission leaking through the patchy absorber.
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- 2016
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7. A rapidly spinning supermassive black hole at the centre of NGC 1365
- Author
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Risaliti, G., Harrison, F.A., Madsen, K.K., Walton, D.J., Boggs, S.E., Christensen, F.E., Craig, W.W., Grefenstette, B.W., Hailey, C.J., Nardini, E., Stern, Daniel, and Zhang, W.W.
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Black holes (Astronomy) -- Observations ,Spiral galaxies -- Observations -- Spectra ,Environmental issues ,Science and technology ,Zoology and wildlife conservation - 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 [...]
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- 2013
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8. A High Resolution Gamma-ray and Hard X-ray Spectrometer (HIREGS) for Long Duration Balloon Flights
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Boggs, S.E., primary, Lin, R.P., additional, Feffer, P.T., additional, Slassi-Sennou, S., additional, McBride, S., additional, Primbsch, J.H., additional, Youssefi, K., additional, Zimmer, G., additional, Cork, C., additional, Luke, P., additional, Madden, N., additional, Malone, D., additional, Pehl, R., additional, Pelling, M., additional, Cotin, F., additional, and Vedrenne, G., additional
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- 1998
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9. Event reconstruction in high resolution Compton telescopes
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Boggs, S.E. and Jean, P.
- Abstract
The development of germanium Compton telescopes for nuclear
$\gamma$ -ray astrophysics ($\sim 0.2-20$ MeV) requires new event reconstruction techniques to accurately determine the initial direction and energy of photon events, as well as to consistently reject background events. This paper describes techniques for event reconstruction, accounting for realistic instrument/detector performance and uncertainties. An especially important technique is Compton Kinematic Discrimination, which allows proper interaction ordering and background rejection with high probabilities. The use of these techniques are crucial for the realistic evaluation of the performance and sensitivity of any germanium Compton telescope configuration.- Published
- 2000
10. NuSTAR reveals the extreme properties of the super-Eddington accreting supermassive black hole in PG 1247+267
- Author
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Duncan Farrah, Franz E. Bauer, M. Cappi, W. N. Brandt, W. W. Zhang, Giorgio Lanzuisi, M. Dadina, Enrico Piconcelli, Fausto Vagnetti, Andrea Comastri, C. J. Hailey, William W. Craig, S. E. Boggs, Fiona A. Harrison, Giorgio Matt, Claudio Ricci, A. C. Fabian, Dom Walton, Andrea Marinucci, F. E. Christensen, Michele Perna, S. Puccetti, David R. Ballantyne, Alberto Masini, D. Stern, C. Vignali, Cristian Saez, B. Luo, Marcella Brusa, Lanzuisi, G., Perna, M., Comastri, A., Cappi, M., Dadina, M., Marinucci, Andrea, Masini, A., Matt, Giorgio, Vagnetti, F., Vignali, C., Ballantyne, D. R., Bauer, F. E., Boggs, S. E., Brandt, W. N., Brusa, M., Christensen, F. E., Craig, W. W., Fabian, A. C., Farrah, D., Hailey, C. J., Harrison, F. A., Luo, B., Piconcelli, E., Puccetti, S., Ricci, C., Saez, C., Stern, D., Walton, D. J., Zhang, W. W., Marinucci, A., Matt, G., Ballantyne, D.R., Bauer, F.E., Boggs, S.E., Brandt, W.N., Christensen, F.E., Craig, W.W., Fabian, A.C., Hailey, C.J., Harrison, F.A., Walton, D.J., and Zhang, W.W.
- Subjects
Accretion ,active [Galaxies] ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Power law ,Relativistic disk ,Quasars: individual: PG 1247+267 ,Accretion, accretion disk ,Settore FIS/05 - Astronomia e Astrofisica ,individual: PG 1247+267 [Quasars] ,Ionization ,0103 physical sciences ,Cutoff ,Emission spectrum ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,Galaxies: nuclei ,Physics ,010308 nuclear & particles physics ,Astronomy and Astrophysics ,Quasar ,Plasma ,Galaxies: active ,Astronomy and Astrophysic ,Redshift ,Space and Planetary Science ,nuclei [Galaxies] ,Accretion disks - Abstract
PG1247+267 is one of the most luminous known quasars at z similar to 2 and is a strongly super-Eddington accreting supermassive black hole (SMBH) candidate. We obtained NuSTAR data of this intriguing source in December 2014 with the aim of studying its high-energy emission, leveraging the broad band covered by the new NuSTAR and the archival XMM-Newton data. Several measurements are in agreement with the super-Eddington scenario for PG1247+267: the soft power law (Gamma = 2.3 +/- 0.1); the weak ionized Fe emission line; and a hint of the presence of outflowing ionized gas surrounding the SMBH. The presence of an extreme reflection component is instead at odds with the high accretion rate proposed for this quasar. This can be explained with three different scenarios; all of them are in good agreement with the existing data, but imply very different conclusions: i) a variable primary power law observed in a low state, superimposed on a reflection component echoing a past, higher flux state; ii) a power law continuum obscured by an ionized, Compton thick, partial covering absorber; and iii) a relativistic disk reflector in a lamp-post geometry, with low coronal height and high BH spin. The first model is able to explain the high reflection component in terms of variability. The second does not require any reflection to reproduce the hard emission, while a rather low high-energy cutoff of similar to 100 keV is detected for the first time in such a high redshift source. The third model require a face-on geometry, which may affect the SMBH mass and Eddington ratio measurements. Deeper X-ray broad-band data are required in order to distinguish between these possibilities.
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- 2016
11. The Phoenix galaxy as seen by NuSTAR
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Stephanie M. LaMassa, Matteo Guainazzi, Fiona A. Harrison, Dominic J. Walton, Walter Craig, C. J. Hailey, Michael Koss, S. E. Boggs, Daniel Stern, Andrea Comastri, Franz E. Bauer, Finn Erland Christensen, Claudio Ricci, M. Brightman, Mislav Baloković, Duncan Farrah, Simonetta Puccetti, P. G. Boorman, William W. Zhang, Poshak Gandhi, Alberto Masini, Masini, A., Comastri, A., Puccetti, S., Baloković, M., Gandhi, P., Guainazzi, M., Bauer, F.E., Boggs, S.E., Boorman, P.G., Brightman, M., Christensen, F.E., Craig, W.W., Farrah, D., Hailey, C.J., Harrison, F.A., Koss, M.J., Lamassa, S.M., Ricci, C., Stern, D., Walton, D.J., and Zhang, W.W.
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Physics ,High Energy Astrophysical Phenomena (astro-ph.HE) ,Seyfert [Galaxies] ,active [Galaxies] ,biology ,010308 nuclear & particles physics ,galaxies: active ,Flux ,FOS: Physical sciences ,Astronomy and Astrophysics ,Context (language use) ,Astrophysics ,Astronomy and Astrophysic ,biology.organism_classification ,01 natural sciences ,Galaxy ,galaxies: Seyfert ,galaxies [X-rays] ,X-rays: galaxies ,Space and Planetary Science ,0103 physical sciences ,Astrophysics - High Energy Astrophysical Phenomena ,Phoenix ,010303 astronomy & astrophysics ,X-rays: galaxie - Abstract
著者人数: 21名, Accepted: 2016-09-01, 資料番号: SA1160316000
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- 2016
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12. NuSTAR reveals extreme absorption in z < 0.5 Type 2 quasars
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Finn Erland Christensen, Fiona A. Harrison, C. J. Hailey, Franz E. Bauer, A. Del Moro, Francesca Civano, James Aird, Roberto J. Assef, Birong Luo, Brian W. Grefenstette, Daniel Stern, Michael Koss, David M. Alexander, L. Zappacosta, Stephanie M. LaMassa, A. Annuar, Simonetta Puccetti, Ryan C. Hickox, M. Brightman, Andrea Comastri, S. E. Boggs, George B. Lansbury, William W. Craig, Poshak Gandhi, William W. Zhang, Mislav Baloković, W. N. Brandt, Ezequiel Treister, David R. Ballantyne, Cristian Vignali, Lansbury, G.B., Gandhi, P., Alexander, D.M., Assef, R.J., Aird, J., Annuar, A., Ballantyne, D.R., Baloković, M., Bauer, F.E., Boggs, S.E., Brandt, W.N., Brightman, M., Christensen, F.E., Civano, F., Comastri, A., Craig, W.W., Del Moro, A., Grefenstette, B.W., Hailey, C.J., Harrison, F.A., Hickox, R.C., Koss, M., Lamassa, S.M., Luo, B., Puccetti, S., Stern, D., Treister, E., Vignali, C., Zappacosta, L., Zhang, W.W., ITA, and USA
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Physics ,education.field_of_study ,active [Galaxies] ,010308 nuclear & particles physics ,Astrophysics::High Energy Astrophysical Phenomena ,Population ,galaxies: active ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astronomy and Astrophysics ,Quasar ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Type (model theory) ,01 natural sciences ,Astrophysics - Astrophysics of Galaxies ,Redshift ,galaxies [X-rays] ,X-rays: galaxies ,Space and Planetary Science ,0103 physical sciences ,Source counts ,Absorption (electromagnetic radiation) ,education ,Astrophysics - High Energy Astrophysical Phenomena ,010303 astronomy & astrophysics - Abstract
The intrinsic column density (NH) distribution of quasars is poorly known. At the high obscuration end of the quasar population and for redshifts z 1.5e24 cm^-2) type 2 quasars (CTQSO2s); five new NuSTAR observations are reported herein, and four have been previously published. The candidate CTQSO2s lie at z~ 90 net source counts at 8-24 keV). For these NuSTAR-detected sources direct (i.e., X-ray spectral) constraints on the intrinsic AGN properties are feasible, and we measure column densities ~2.5-1600 times higher and intrinsic (unabsorbed) X-ray luminosities ~10-70 times higher than pre-NuSTAR constraints from Chandra and XMM-Newton. Assuming the NuSTAR-detected type 2 quasars are representative of other Compton-thick candidates, we make a correction to the NH distribution for optically selected type 2 quasars as measured by Chandra and XMM-Newton for 39 objects. With this approach, we predict a Compton-thick fraction of f_CT = 36^{+14}_{-12} %, although higher fractions (up to 76%) are possible if indirect absorption diagnostics are assumed to be reliable., Comment: 19 pages, 13 figures, 5 tables. Accepted for publication in ApJ
- Published
- 2015
13. NuSTAR J033202-2746.8: direct constraints on the Compton reflection in a heavily obscured quasar at z~2
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Piero Ranalli, Simonetta Puccetti, James Aird, Meg Urry, Stephanie M. LaMassa, S. E. Boggs, David M. Alexander, Fiona A. Harrison, C. J. Hailey, George B. Lansbury, William W. Zhang, Francesca Civano, Andrea Comastri, Finn Erland Christensen, James Mullaney, W. N. Brandt, William W. Craig, Mislav Baloković, Daniel Stern, Poshak Gandhi, Ryan C. Hickox, Birong Luo, A. Del Moro, David R. Ballantyne, Cristian Vignali, Ezequiel Treister, Roberto Gilli, Franz E. Bauer, Del Moro A., Mullaney J.R., Alexander D.M., Comastri A., Bauer F.E., Treister E., Stern D., Civano F., Ranalli P., Vignali C., Aird J.A., Ballantyne D., Balokovic M., Boggs S.E., Brandt W.N., Christensen S.E., Craig W.W., Gandhi P., Gilli R., Hailey C.J., Harrison F.A., Hickox R.C., LaMassa S.M., Lansbury G.B., Luo B., Puccetti S., Urry M., and Zhang W.W.
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Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Spectral shape analysis ,active [Galaxies] ,010504 meteorology & atmospheric sciences ,Astrophysics::High Energy Astrophysical Phenomena ,Population ,galaxies: active ,General [quasars] ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Luminosity ,Galaxies [infrared] ,quasars: individual (NuSTAR J033202-2746.8) ,quasars: general ,X-rays ,0103 physical sciences ,Spectral slope ,individual (NuSTAR J033202-2746.8) [quasars] ,Spectroscopy ,education ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,Physics ,education.field_of_study ,infrared: galaxie ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astronomy and Astrophysics ,Quasar ,Astrophysics - Astrophysics of Galaxies ,Redshift ,X-rays: galaxies ,K-edge ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We report NuSTAR observations of NuSTAR J033202-2746.8, a heavily obscured, radio-loud quasar detected in the Extended Chandra Deep Field-South, the deepest layer of the NuSTAR extragalactic survey (~400 ks, at its deepest). NuSTAR J033202-2746.8 is reliably detected by NuSTAR only at E>8 keV and has a very flat spectral slope in the NuSTAR energy band (Gamma=0.55^{+0.62}_{-0.64}; 3-30 keV). Combining the NuSTAR data with extremely deep observations by Chandra and XMM-Newton (4 Ms and 3 Ms, respectively), we constrain the broad-band X-ray spectrum of NuSTAR J033202-2746.8, indicating that this source is a heavily obscured quasar (N_H=5.6^{+0.9}_{-0.8}x10^23 cm^-2) with luminosity L_{10-40 keV}~6.4x10^44 erg s^-1. Although existing optical and near-infrared (near-IR) data, as well as follow-up spectroscopy with the Keck and VLT telescopes, failed to provide a secure redshift identification for NuSTAR J033202-2746.8, we reliably constrain the redshift z=2.00+/-0.04 from the X-ray spectral features (primarily from the iron K edge). The NuSTAR spectrum shows a significant reflection component (R=0.55^{+0.44}_{-0.37}), which was not constrained by previous analyses of Chandra and XMM-Newton data alone. The measured reflection fraction is higher than the R~0 typically observed in bright radio-loud quasars such as NuSTAR J033202-2746.8, which has L_{1.4 GHz}~10^27 W Hz^-1. Constraining the spectral shape of AGN, including bright quasars, is very important for understanding the AGN population, and can have a strong impact on the modeling of the X-ray background. Our results show the importance of NuSTAR in investigating the broad-band spectral properties of quasars out to high redshift., 13 pages, 5 figures; accepted for publication in ApJ
- Published
- 2014
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