Results 11 to 20 of about 195 (150)
Ultraluminous X-Ray Sources [PDF]
Astrophysical Bulletin, 2021 32 pages, 21 figures, 1 ...
Fabrika S.N. +3 more
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Wind-powered Ultraluminous X-ray Sources [PDF]
The Astrophysical Journal, 2021 Abstract Although ultraluminous X-ray sources (ULX) are important for astrophysics because of their extreme apparent super-Eddington luminosities, their nature is still poorly known. Theoretical and observational studies suggest that ULXs could be a diversified group of objects that are composed of low-mass X-ray binaries, high-mass X ...
Grzegorz Wiktorowicz +5 more
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Observations of Ultraluminous X-ray Sources [PDF]
AIP Conference Proceedings, 2010 Review talk given at the meeting Mykonos-2010:"Binary Star Evolution: Mass Loss, Accretion, and Mergers".
Jeanette C. Gladstone +2 more
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The Origin of the Ultraluminous X-Ray Sources [PDF]
The Astrophysical Journal, 2017 Abstract Recently, several ultraluminous X-ray (ULX) sources were shown to host a neutron star (NS) accretor. We perform a suite of evolutionary calculations, which show that, in fact, NSs are the dominant type of ULX accretor. Although black holes (BH) dominate early epochs after the star-formation burst, NSs outweigh them after a few ...
Wiktorowicz, Grzegorz +3 more
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X-RAY MONITORING OF ULTRALUMINOUS X-RAY SOURCES [PDF]
The Astrophysical Journal, 2009 X-ray monitoring observations were performed with the Swift observatory of the ultraluminous X-ray sources Holmberg IX X-1, NGC 5408 X-1, and NGC 4395 X-2 and also of the nuclear X-ray source in NGC 4395. Holmberg IX X-1 remains in the hard X-ray spectral state as its flux varies by a factor of 7 up to an (isotropic) luminosity of 2.8E40 erg/s.
Kaaret, Philip, Feng, Hua
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The Hunt for Pulsating Ultraluminous X-ray Sources [PDF]
Monthly Notices of the Royal Astronomical Society, 2019 Abstract Motivated by the recent discoveries that six Ultraluminous X-ray Sources (ULXs) are powered by highly super-Eddington X-ray pulsars, we searched for additional pulsating ULX (PULX) candidates by identifying sources that exhibit long-term flux variability of at least an order of magnitude (a common feature seen in the 6 known ...
X Song +6 more
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NATURE OF THE EXTREME ULTRALUMINOUS X-RAY SOURCES [PDF]
The Astrophysical Journal, 2015 In this proof-of-concept study we demonstrate that in a binary system mass can be transferred toward an accreting compact object at extremely high rate. If the transferred mass is efficiently converted to X-ray luminosity (with disregard of the classical Eddington limit) or if the X-rays are focused into a narrow beam then binaries can form extreme ULX
Wiktorowicz, Grzegorz +3 more
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Ultraluminous X-ray Sources [PDF]
Proceedings of Accretion Processes in Cosmic Sources – II — PoS(APCS2018), 2019 Ultraluminous X-ray sources (ULXs) represent a class of binary systems that are more luminous than any black hole in our Galaxy. The nature of these objects remained unclear for a long time. The most popular models for the ULXs involve either intermediate mass black holes (IMBHs) or stellar-mass black holes accreting at super-Eddington rates.
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Classifying the Zoo of Ultraluminous X-ray Sources [PDF]
Chinese Journal of Astronomy and Astrophysics, 2005 Ultraluminous X-ray sources (ULXs) are likely to include different physical types of objects. We discuss some possible subclasses, reviewing the properties of a sample of ULXs recently observed by Chandra and XMM-Newton. Sources with an isotropic X-ray luminosity up to a few times 10^{39} erg/s are consistent with ``normal'' stellar-mass X-ray binaries
Soria, Roberto, Cropper, M., Motch, C.
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Ultrafast outflows in ultraluminous X‐ray sources [PDF]
Astronomische Nachrichten, 2017 Ultraluminous X‐ray sources (ULXs) are bright extragalactic sources with X‐ray luminosities above 1039 erg s−1 powered by accretion onto compact objects. According to the first studies performed with XMM‐Newton, ULXs seemed to be excellent candidates to host intermediate‐mass black holes (102 − 4M⊙).
Pinto, C. +3 more
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