Ultraluminous X-ray Sources in the Chandra and XMM-Newton Era

Abstract

Ultraluminous X-ray sources (ULXs) are accreting black holes that may contain the missing population of intermediate mass black holes or reflect super-Eddington accretion physics. Ten years of Chandra and XMM-Newton observations of ULXs, integrated by multiband studies of their counterparts, have produced a wealth of observational data and phenomenological classifications. We review the properties of their host galaxies, list popular spectral models and implications for standard and supercritical accretion physics, demonstrate how X-ray timing of these objects places constraints on their masses. We also review multiwavelength studies of ULXs, including the optical emission of the binary system and nebulosity around them. We summarize that three classes of black holes could power ULXs: normal stellar mass black holes (~10 solar masses), massive stellar black holes (~< 100 solar masses), and intermediate mass black holes (10^2 - 10^4 solar masses). We collect evidence for the presence of these three types of compact objects, including caveat of each interpretation, and briefly review their formation processes.

Solicited review in New Astronomy Reviews. v2: final version for publication, 21 pages, 5 figures, references added, small revisions made, thanks to many colleagues for useful comments

References in corpus (52)

• X-ray Properties of Black-Hole Binaries
• The MAPPINGS III Library of Fast Radiative Shock Models
• The R136 star cluster hosts several stars whose individual masses greatly exceed the accepted 150 Msun stellar mass limit
• Super-critically accreting stellar-mass black holes as ultraluminous X-ray sources
• Magnetic acceleration of relativistic AGN jets
• XMM-Newton observations of the brightest Ultraluminous X-ray sources
• The Nature of SS433 and the Ultraluminous X-ray Sources
• A 15.65 solar mass black hole in an eclipsing binary in the nearby spiral galaxy Messier 33
• Masses, Beaming and Eddington Ratios in Ultraluminous X-ray Sources
• X-ray observations of ultraluminous X-ray sources
• On IC 10 X-1, the Most Massive Known Stellar-Mass Black Hole
• The 2003 Outburst of the X-ray Transient H 1743-322: Comparisons with the Black Hole Microquasar XTE J1550-564
• The Orbital Period of the Wolf-Rayet Binary IC 10 X-1; Dynamic Evidence that the Compact Object is a Black Hole
• Wandering Black Holes in Bright Disk Galaxy Halos
• Low metallicity and ultra-luminous X-ray sources in the Cartwheel galaxy
• On the evolution and fate of supermassive stars
• The jet-powered optical nebula of Cygnus X-1
• The variability plane of accreting compact objects
• A 62 Day X-Ray Periodicity and an X-Ray Flare from the Ultraluminous X-Ray Source in M82
• Spectral State Transitions of the Ultraluminous X-ray Sources X-1 and X-2 in NGC 1313
• On the weakness of disc models in bright ULXs
• The ultraluminous X-ray source NGC 1313 X-2 - Its optical counterpart and environment
• Spectroscopy of Optical Counterparts of Ultraluminous X-ray Sources
• Identification of the X-Ray Thermal Dominant State in an Ultraluminous X-Ray Source in M82
• Optical emission from massive donors in ULX binary systems
• Testing the Paradigm that Ultraluminous X-ray Sources as a Class Represent Accreting Intermediate-Mass Black Holes
• Bridging the gap between stellar-mass black holes and ultraluminous X-ray sources
• Optical Properties of the Ultraluminous X-ray Source Holmberg IX X-1 and its Stellar Environment
• Irradiation models for ULXs and fits to optical data
• Discovery of mHz X-ray Oscillations in a Transient Ultraluminous X-ray Source in M82
• Do Ultraluminous X-Ray Sources Exist in Dwarf Galaxies?
• Models for the Observable System Parameters of Ultraluminous X-ray Sources
• Weighing the black holes in ultraluminous X-ray sources through timing
• A ULX microquasar in NGC 5408?
• Confirmation of the 62 Day X-Ray Periodicity from M82
• How rapidly do neutron stars spin at birth? Constraints from archival X-ray observations of extragalactic supernovae
• X-ray spectral state is not correlated with luminosity in Holmberg II X-1
• On the compact nature of the most luminous ULX in the Cartwheel ring
• The Orbital Period of the Ultraluminous X-ray Source in M82
• Radio and X-ray Properties of Relativistic Beaming Models for Ultra-Luminous X-ray Sources
• On the Eddington limit in accretion discs
• Detailed Atmosphere Model Fits to Disk-Dominated ULX Spectra
• Ultraluminous X-ray Sources: Bubbles and Optical Counterparts
• Kinetically Dominated FRII Radio Sources
• Interpretation of the 115 Day Periodic Modulation in the X-ray Flux of NGC 5408 X-1
• A Comparison of Ultraluminous X-ray Sources in NGC 1399 and the Antennae Galaxies (NGC 4038/4039)
• An ultraluminous supersoft source with a 4 hour modulation in NGC 4631
• Ultraluminous X-ray Sources: Beambags and Optical Counterparts
• No periodicity revealed for an "eclipsing" ultraluminous supersoft X-ray source in M81
• Transition to the disk dominant state of a new ultraluminous X-ray source in M82
• The ULX NGC 1313 X-2 : an optical study revealing an interesting behavior
• Large-scale radio nebula around the Ultra-Luminous X-ray Source IC 342 X-1

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• The ultraluminous X-ray sources NGC 1313 X-1 and X-2: a broadband study with NuSTAR and XMM-Newton
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• On the Formation of Ultraluminous X-ray Sources with Neutron Star Accretors: the Case of M82 X-2
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• Evidence for precession due to supercritical accretion in ultraluminous X-ray sources
• Intermediate Mass-Ratio Inspirals with Dark Matter Minispikes
• Chandra reveals a possible ultra-fast outflow in the super-Eddington Be/X-ray binary Swift J0243.6+6124
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• Milliarcsec-scale radio emission of ultraluminous X-ray sources: steady jet emission from an intermediate-mass black hole?
• Periodic signals from the Circinus region: two new cataclysmic variables and the ultraluminous X-ray source candidate GC X-1
• Irradiated, colour-temperature-corrected accretion discs in ultraluminous X-ray sources
• Searching for Massive Outflows in Holmberg IX X-1 and NGC 1313 X-1: The Iron K Band
• The Broadband Spectral Variability of Holmberg IX X-1
• Review of scientific topics for Millimetron space observatory
• Multiband counterparts of two eclipsing ultraluminous X-ray sources in M 51
• Highlights and Discoveries from the Chandra X-ray Observatory
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