Results 91 to 100 of about 37,815 (249)
Galaxies, 2022 The observed Tully-Fisher and Faber-Jackson laws between the baryonic mass of galaxies and the velocity of motion of stars at the edge of galaxies are explained within the framework of the model of accretion of galaxies around supermassive black holes ...
Nick Gorkavyi
doaj +1 more source
Dark energy and supermassive black holes [PDF]
Physical Review D, 2004 This paper deals with a cosmological model in which the universe is filled with tachyon dark energy in order to describe current and future accelerating expansion. We obtain that the simplest condition for the regime of phantom energy to occur in this scenario is that the scalar field be Wick rotated to imaginary values which correspond to an axionic ...
openaire +4 more sources
Constraints on alternatives to supermassive black holes [PDF]
Monthly Notices of the Royal Astronomical Society: Letters, 2006 Abstract Observations of the centres of galaxies continue to evolve, and it is useful to take a fresh look at the constraints that exist on alternatives to supermassive black holes at their centres. We discuss constraints complementary to those of Maoz and demonstrate that an extremely wide range of other possibilities can be excluded ...
M. Coleman Miller, M. Coleman Miller
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Expectations for Horizon-Scale Supermassive Black Hole Population Studies with the ngEHT
Galaxies, 2022 We present estimates for the number of supermassive black holes (SMBHs) for which the next-generation Event Horizon Telescope (ngEHT) can identify the black hole “shadow”, along with estimates for how many black hole masses and spins the ngEHT can expect
Dominic W. Pesce +7 more
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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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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.
core +1 more source
The formation of supermassive black holes and the evolution of supermassive stars [PDF]
Classical and Quantum Gravity, 2001 The existence of supermassive black holes is supported by a growing body of observations. Supermassive black holes and their formation events are likely candidates for detection by proposed long-wavelength, space-based gravitational wave interferometers like LISA.
Stuart L. Shapiro, Kimberly C. B. New
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Where are all the gravastars? Limits upon the gravastar model from accreting black holes [PDF]
, 2007 The gravastar model, which postulates a strongly correlated thin shell of anisotropic matter surrounding a region of anti-de Sitter space, has been proposed as an alternative to black holes.
Avery E Broderick +8 more
core +2 more sources
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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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
core +1 more source