Results 31 to 40 of about 238,966 (146)
Modeling the High-energy Ionizing Output from Simple Stellar and X-Ray Binary Populations
The Astrophysical Journal, 2023 We present a methodology for modeling the joint ionizing impact due to a “simple X-ray population” (SXP) and its corresponding simple stellar population (SSP), where “simple” refers to a single age and metallicity population.
Kristen Garofali +11 more
doaj +1 more source
Ultrafast outflows in ultraluminous X-ray sources [PDF]
, 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).
arxiv +1 more source
Transition to the disk dominant state of a new ultraluminous X-ray source in M82 [PDF]
Astrophysical Journal 716 (2010) 181-186, 2010 We report on the identification of a third, new ultraluminous X-ray source (ULX) in the starburst galaxy M82. Previously, the source was observed at fluxes consistent with the high state of Galactic black hole binaries (BHBs). We observe fluxes up to (6.5 +/- 0.3)E39 ergs/s in the ultraluminous regime.
arxiv +1 more source
The nature of the ultraluminous X-ray sources inside galaxies and their relation to local QSOs [PDF]
Astron.Astrophys. 400 (2003) L17, 2002 It is suggested that many of the ultraluminous compact x-ray sources now being found in the main bodies of galaxies, particularly those that are active, like M82, NGC 3628 and others, are "local" QSOs, or BL Lac objects, with high intrinsic redshifts in the process of being ejected from those galaxies.
arxiv +1 more source
Phase-dependent Spectral Shape Changes in the Ultraluminous X-Ray Pulsar NGC 5907 ULX1
The Astrophysical JournalThe discovery of coherent pulsations from several ultraluminous X-ray pulsars (ULXPs) has provided direct evidence of a supercritical accretion flow.
Daiki Miura +2 more
doaj +1 more source
Stellar Mass Black Holes and Ultraluminous X-Ray Sources [PDF]
Science 337, 540 (2012), 2012 We review the likely population, observational properties, and broad implications of stellar-mass black holes and ultraluminous x-ray sources. We focus on the clear empirical rules connecting accretion and outflow that have been established for stellar-mass black holes in binary systems in the past decade and a half.
arxiv +1 more source
Return to the Forgotten Ultraluminous X-Ray Source: A Broadband NICER+NuSTAR Study of NGC 4190 ULX-1
The Astrophysical JournalWe observed the nearby and relatively understudied ultraluminous X-ray source (ULX) NGC 4190 ULX-1 jointly with Neutron Star Interior Composition Explorer (NICER) and NuSTAR to investigate its broadband spectrum, timing properties, and spectral variation
Hannah P. Earnshaw +9 more
doaj +1 more source
Direct Detection of an Ultraluminous Ultraviolet Source [PDF]
, 2010 We present Hubble Space Telescope observations in the far UV of the ultraluminous X-ray source in NGC 6946 associated with the optical nebula MF 16. Both a point-like source coincident with the X-ray source and the surrounding nebula are detected in the FUV. The point source has a flux of 5E-16 erg s^-1 cm^-2 Ang^-1 and the nebula has a flux of 1.6E-15
arxiv +1 more source
X-Ray Monitoring of Ultraluminous X-Ray Sources [PDF]
, 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.
arxiv +1 more source
The Astrophysical JournalUltraluminous X-ray sources (ULXs) were once largely believed to be powered by super-Eddington accretion onto stellar-mass black holes, although in some rare cases, ULXs also serve as potential candidates for (sub-Eddington) intermediate-mass black holes.
Teresa Panurach +10 more
doaj +1 more source