Preprint article ยท Journal article
A Hard X-Ray Study of the Normal Star-Forming Galaxy M83 with NuSTAR
Johns Hopkins University1
Astrophysics and Atmospheric Physics, National Space Institute, Technical University of Denmark2
Lawrence Livermore National Laboratory3
Columbia University4
California Institute of Technology5
Russian Academy of Sciences6
Harvard-Smithsonian Center for Astrophysics7
Texas Tech University8
New Mexico Institute of Mining and Technology9
NASA Goddard Space Flight Center10
University of Manchester11
Kavli Institute for Cosmological Physics12
University of California at Berkeley13
National Space Institute, Technical University of Denmark14
...and 4 moreWe present the results from sensitive, multi-epoch NuSTAR observations of the late-type star-forming galaxy M83 (d = 4.6 Mpc). This is the first investigation to spatially resolve the hard (E > 10 keV) X-ray emission of this galaxy. The nuclear region and similar to 20 off-nuclear point sources, including a previously discovered ultraluminous X-ray source, are detected in our NuSTAR observations.
The X-ray hardnesses and luminosities of the majority of the point sources are consistent with hard X-ray sources resolved in the starburst galaxy NGC 253. We infer that the hard X-ray emission is most likely dominated by intermediate accretion state black hole binaries and neutron star low-mass X-ray binaries (Z-sources).
We construct the X-ray binary luminosity function (XLF) in the NuSTAR band for an extragalactic environment for the first time. The M83 XLF has a steeper XLF than the X-ray binary XLF in NGC 253, which is consistent with previous measurements by Chandra at softer X-ray energies. The NuSTAR integrated galaxy spectrum of M83 drops quickly above 10 keV, which is also seen in the starburst galaxies NGC 253, NGC 3310, and NGC 3256.
The NuSTAR observations constrain any active galactic nucleus (AGN) to be either highly obscured or to have an extremely low luminosity of less than or similar to 1038 erg s-1 (10-30 keV), implying that it is emitting at a very low Eddington ratio. An X-ray point source that is consistent with the location of the nuclear star cluster with an X-ray luminosity of a few times 1038 erg s-1 may be a low-luminosity AGN but is more consistent with being an X-ray binary.
Language: | English |
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Publisher: | American Astronomical Society |
Year: | 2016 |
Pages: | 107 |
ISSN: | 15384357 and 0004637x |
Types: | Preprint article and Journal article |
DOI: | 10.3847/0004-637X/824/2/107 |
ORCIDs: | Christensen, Finn Erland , 0000-0001-5655-1440 , 0000-0001-8952-676X , 0000-0003-3594-0214 , 0000-0003-2737-5673 , 0000-0001-6654-5378 and 0000-0003-2686-9241 |