The NuSTAR ULX program

Bachetti Matteo; Barret Didier; Boggs Steven E.; Christensen Finn E.; Craig William W.; Fabian Andrew C.; Forster Karl; Fürst Felix; Grefenstette Brian W.; Hailey Charles J.; Harrison Fiona A.; Hornschemeier Ann E.; Madsen Kristin K.; Miller Jon M.; Parker Michael; Ptak Andrew; Rana Vikram R.; Risaliti Guido; Stern Daniel; Walton Dominic J.; Webb Natalie A.; Zhang William W.

doi:10.1051/epjconf/20136406010

EPJ Web of Conferences (Jan 2014)

The NuSTAR ULX program

Bachetti Matteo,
Barret Didier,
Boggs Steven E.,
Christensen Finn E.,
Craig William W.,
Fabian Andrew C.,
Forster Karl,
Fürst Felix,
Grefenstette Brian W.,
Hailey Charles J.,
Harrison Fiona A.,
Hornschemeier Ann E.,
Madsen Kristin K.,
Miller Jon M.,
Parker Michael,
Ptak Andrew,
Rana Vikram R.,
Risaliti Guido,
Stern Daniel,
Walton Dominic J.,
Webb Natalie A.,
Zhang William W.

Affiliations

Bachetti Matteo: INAF - Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5
Barret Didier: INAF - Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5
Boggs Steven E.: Space Sciences Laboratory, University of California
Christensen Finn E.: DTU Space, National Space Institute, Technical University of Denmark
Craig William W.
Fabian Andrew C.: Institute of Astronomy, University of Cambridge
Forster Karl: Cahill Center for Astronomy and Astrophysics, California Institute of Technology
Fürst Felix: Cahill Center for Astronomy and Astrophysics, California Institute of Technology
Grefenstette Brian W.: Cahill Center for Astronomy and Astrophysics, California Institute of Technology
Hailey Charles J.: Columbia Astrophysics Laboratory, Columbia University
Harrison Fiona A.: Cahill Center for Astronomy and Astrophysics, California Institute of Technology
Hornschemeier Ann E.: NASA Goddard Space Flight Center
Madsen Kristin K.: Department of Astronomy, University of Michigan
Miller Jon M.: NASA Goddard Space Flight Center
Parker Michael: Space Sciences Laboratory, University of California
Ptak Andrew: NASA Goddard Space Flight Center
Rana Vikram R.: Cahill Center for Astronomy and Astrophysics, California Institute of Technology
Risaliti Guido
Stern Daniel: Jet Propulsion Laboratory, California Institute of Technology
Walton Dominic J.: Cahill Center for Astronomy and Astrophysics, California Institute of Technology
Webb Natalie A.: INAF - Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5
Zhang William W.: NASA Goddard Space Flight Center

DOI: https://doi.org/10.1051/epjconf/20136406010
Journal volume & issue: Vol. 64
p. 06010

Abstract

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We present the results of the first large program of broadband ULX observations with NuSTAR, XMM–Newton and Suzaku, yielding high-quality spectra and timing measurements from 0.3–30 keV in 6 ULXs, providing powerful information for understanding the accretion modes and nature of the central BHs. In particular, we find that all ULXs in our sample have a clear cutoff above 10 keV. This cutoff is less pronounced than expected by Comptonization from a cold, thick corona. We confirm the presence of a soft excess at low energies in the brightest ULXs, with temperatures below ~ 0.5 keV. We make an estimates on the masses of several ULXs based on spectral variability and model fitting.

Published in EPJ Web of Conferences

ISSN: 2100-014X (Online)
Publisher: EDP Sciences
Country of publisher: France
LCC subjects: Science: Physics
Website: http://www.epj-conferences.org/

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