Results 131 to 140 of about 264,425 (308)
Supermassive black holes in galactic nuclei
AIP Conference Proceedings, 2001 We review the motivation and search for supermassive black holes (BHs) in galaxies. Energetic nuclear activity provides indirect but compelling evidence for BH engines. Ground-based dynamical searches for central dark objects are reviewed in Kormendy & Richstone (1995, ARA&A, 33, 581). Here we provide an update of results from the HST.
John Kormendy, Karl Gebhardt
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Supermassive black holes in the early Universe [PDF]
Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2015 The recent discovery of the ultraluminous quasar SDSS J010013.02+280225.8 at redshift 6.3 has exacerbated the time compression problem implied by the appearance of supermassive black holes only approximately 900 Myr after the big bang, and only approximately 500 Myr beyond the formation of Pop II and III stars.
F. Melia, T. M. McClintock
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Null Geodesics and Strong Field Gravitational Lensing in a String Cloud Background
Advances in High Energy Physics, 2015 This paper is devoted to studying two interesting issues of a black hole with string cloud background. Firstly, we investigate null geodesics and find unstable orbital motion of particles. Secondly, we calculate deflection angle in strong field limit. We
M. Sharif, Sehrish Iftikhar
doaj +1 more source
The Megamaser Cosmology Project: IV. A Direct Measurement of the Hubble Constant from UGC 3789
, 2013 In Papers I and II from the Megamaser Cosmology Project (MCP), we reported initial observations of water masers in an accretion disk of a supermassive black hole at the center of the galaxy UGC 3789, which gave an angular-diameter distance to the galaxy ...
Argon +20 more
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M87 Supermassive Black Hole Review
International Journal of Science and Research (IJSR), 2021 M87 is a giant elliptical galaxy in the Virgo cluster of galaxies. The radio source has a core which coincides with the nucleus of the galaxy and a jet of emission which is detected from radio to X-ray bands. A supermassive black hole is assumed to be at the centre of M87 which sends out relativistic particles in the form jets along its axis of ...
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A highly magnetized twin-jet base pinpoints a supermassive black hole [PDF]
, 2016 Supermassive black holes (SMBH) are essential for the production of jets in radio-loud active galactic nuclei (AGN). Theoretical models based on (Blandford & Znajek 1977, MNRAS, 179, 433) extract the rotational energy from a Kerr black hole, which could ...
A. Baczko +20 more
semanticscholar +1 more source
Low-mass black holes as the remnants of primordial black hole formation [PDF]
, 2012 This article documents our ongoing search for the elusive "intermediate-mass" black holes. These would bridge the gap between the approximately ten solar mass "stellar-mass" black holes that are the end-product of the life of a massive star, and the "supermassive" black holes with masses of millions to billions of solar masses found at the centers of ...
arxiv +1 more source
The local supermassive black hole mass density: corrections for dependencies on the Hubble constant
, 2007 We have investigated past measurements of the local supermassive black hole mass density, correcting for hitherto unknown dependencies on the Hubble constant, which, in some cases, had led to an underestimation of the mass density by factors of ~2 ...
Driver, Simon P., Graham, Alister W.
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On the location of the supermassive black hole in CTA 102 [PDF]
Astronomy & Astrophysics, 2015 Relativistic jets in active galactic nuclei represent one of the most powerful phenomena in the Universe. They form in the surroundings of the supermassive black holes as a by-product of accretion onto the central black hole in active galaxies. The flow in the jets propagates at velocities close to the speed of light.
J. Anton Zensus +6 more
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Close supermassive binary black holes [PDF]
Nature, 2010 Nature in press. 4 pages, 1 figure [Title, abstract, text, and references shortened to conform to journal requirements]
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