Results 1 to 10 of about 245,395 (235)
Radio Emission from an Ultraluminous X-Ray Source [PDF]
Science 299 (2003) 365-367, 2003 The physical nature of ultraluminous x-ray sources is uncertain. Stellar mass black holes with beamed radiation and intermediate mass black holes with isotropic radiation are two plausible explanations. We discovered radio emission from an ultraluminous x-ray source in the dwarf irregular galaxy NGC 5408.
Corbel, Stephane +3 more
arxiv +10 more sources
Ultraluminous X-ray Sources and Their Nebulae [PDF]
AIP Conf.Proc.1054:33-38,2008, 2008 One of the interesting features of Ultraluminous X-ray sources is that many of them are surrounded by luminous nebulae exhibiting diverse observational properties. In different cases the nebulae are photoionized or shock-powered. Generally, the two energy sources appear to coexist.
Magnus Axelsson, Pavel Abolmasov
arxiv +9 more sources
Observations of ultraluminous X-ray sources [PDF]
AIP Conference Proceedings, 2011 Ultraluminous X-ray sources (ULXs), first observed ~30 years ago, have been argued as extreme stellar mass black hole binaries or a new class intermediate mass black hole. In order to settle this debate, scientists have utilised a wide range of telescopes, exploiting large sections of the electro-magnetic spectrum.
Gladstone, Jeanette Claire
arxiv +6 more sources
Spectral variability of ultraluminous X-ray sources [PDF]
AIP Conference Proceedings, 2008 We study spectral variability of 11 ultraluminous X-ray sources (ULX) using archived XMM-Newton and Chandra observations. We use three models to describe the observed spectra; a power-law, a multi-colour disk (MCD) and a combination of these two models ...
Abolmasov +60 more
core +8 more sources
Ultraluminous X-Ray Sources [PDF]
Astrophysical Bulletin, 2021, V. 76, N. 1, pp. 6-38, 2021 Ultraluminous X-ray sources (ULXs) were identified as a separate class of objects in 2000 based on data from the Chandra X-Ray Observatory. These are unique objects: their X-ray luminosities exceed the Eddington limit for a typical stellar-mass black hole. For a long time, the nature of ULXs remained unclear.
Alexander Vinokurov +4 more
arxiv +6 more sources
Ultraluminous X-ray sources [PDF]
New Astronomy Reviews, 2023, Volume 96, article id. 101672, 2023 The study of ultraluminous X-ray sources (ULXs) has changed dramatically over the last decade. In this review we first describe the most important observations of ULXs in various wavebands, and across multiple scales in space and time. We discuss recent progress and current unanswered questions.
King, A., Lasota, J.-P., Middleton, M.
arxiv +5 more sources
Synchrotron Cutoff in Ultraluminous X-Ray Sources
The Astrophysical Journal, 2023 The origin of spectral curvature at energies E ≃ 10 keV in ultraluminous X-ray sources (ULXs) is not well understood. In this paper, we propose a novel mechanism based on synchrotron radiation to explain this cutoff.
Tanuman Ghosh, Shiv Sethi, Vikram Rana
doaj +3 more sources
Ultraluminous X-ray sources are beamed [PDF]
Monthly Notices of the Royal Astronomical Society, 2023 We show that magnetar models for ULX behaviour have serious internal inconsistencies. The magnetic fields required to increase the limiting luminosity for radiation pressure above the observed (assumed isotropic) luminosities are completely incompatible ...
King, Andrew, Lasota, Jean-Pierre
core +8 more sources
Ultrafast outflows in ultraluminous X-ray sources [PDF]
Astronomische Nachrichten, 2016 Ultraluminous X-ray sources (ULXs) are bright extragalactic sources with X-ray luminosities above 10^39 erg/s 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 (10^2-4 solar masses).
Ciro Pinto +5 more
arxiv +7 more sources
A 62 Day X-Ray Periodicity and an X-Ray Flare from the Ultraluminous X-Ray Source in M82 [PDF]
Astrophys.J. 646 (2006) 174-183, 2006 In 240 days of X-ray monitoring of M82, we have discovered an X-ray periodicity at $62.0 \pm 2.5$ days with a peak to peak amplitude corresponding to an isotropic luminosity of $2.4 \times 10^{40} \rm erg s^{-1}$ in M82 and an X-ray flare reaching a peak luminosity of $9.8 \times 10^{40} \rm erg s^{-1}$.
P. Kaaret +2 more
arxiv +3 more sources