Results 11 to 20 of about 168,088 (243)

Formation of Supermassive Black Hole Seeds [PDF]

open access: yesPublications of the Astronomical Society of Australia, 2016
AbstractThe detection of quasars at z > 6 unveils the presence of supermassive black holes of a few billion solar masses. The rapid formation process of these extreme objects remains a fascinating and open issue. Such discovery implies that seed black holes must have formed early on, and grown via either rapid accretion or BH/galaxy mergers. In this
Latif, M., FERRARA, ANDREA
semanticscholar   +6 more sources

The Proper Motion of Sagittarius A*. III. The Case for a Supermassive Black Hole [PDF]

open access: bronzeAstrophysical Journal, 2020
We report measurements with the Very Long Baseline Array of the proper motion of Sgr A* relative to two extragalactic radio sources spanning 18 yr. The apparent motion of Sgr A* is −6.411 ± 0.008 mas yr−1 along the Galactic plane and −0.219 ± 0.007 mas ...
M. Reid, A. Brunthaler
semanticscholar   +3 more sources

Supermassive Black Hole Feedback

open access: yes, 2019
Understanding the processes that drive galaxy formation and shape the observed properties of galaxies is one of the most interesting and challenging frontier problems of modern astrophysics. We now know that the evolution of galaxies is critically shaped by the energy injection from accreting supermassive black holes (SMBHs). However, it is unclear how
Ruszkowski, Mateusz   +25 more
openaire   +4 more sources

The NANOGrav 15 yr Data Set: Constraints on Supermassive Black Hole Binaries from the Gravitational-wave Background [PDF]

open access: yesAstrophysical Journal Letters, 2023
The NANOGrav 15 yr data set shows evidence for the presence of a low-frequency gravitational-wave background (GWB). While many physical processes can source such low-frequency gravitational waves, here we analyze the signal as coming from a population of
G. Agazie   +113 more
semanticscholar   +1 more source

A CEERS Discovery of an Accreting Supermassive Black Hole 570 Myr after the Big Bang: Identifying a Progenitor of Massive z > 6 Quasars [PDF]

open access: yesAstrophysical Journal Letters, 2023
We report the discovery of an accreting supermassive black hole at z = 8.679. This galaxy, denoted here as CEERS_1019, was previously discovered as a Lyα-break galaxy by Hubble with a Lyα redshift from Keck.
R. Larson   +50 more
semanticscholar   +1 more source

The NANOGrav 15 yr Data Set: Bayesian Limits on Gravitational Waves from Individual Supermassive Black Hole Binaries [PDF]

open access: yesAstrophysical Journal Letters, 2023
Evidence for a low-frequency stochastic gravitational-wave background has recently been reported based on analyses of pulsar timing array data. The most likely source of such a background is a population of supermassive black hole binaries, the loudest ...
G. Agazie   +98 more
semanticscholar   +1 more source

First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way [PDF]

open access: yes, 2023
We present the first Event Horizon Telescope (EHT) observations of Sagittarius A* (Sgr A$^*$), the Galactic center source associated with a supermassive black hole.
K. Akiyama   +387 more
semanticscholar   +1 more source

The NANOGrav 12.5 yr Data Set: Bayesian Limits on Gravitational Waves from Individual Supermassive Black Hole Binaries [PDF]

open access: yesAstrophysical Journal Letters, 2023
Pulsar timing array collaborations, such as the North American Nanohertz Observatory for Gravitational Waves (NANOGrav), are seeking to detect nanohertz gravitational waves emitted by supermassive black hole binaries formed in the aftermath of galaxy ...
Z. Arzoumanian   +77 more
semanticscholar   +1 more source

First Sagittarius A* Event Horizon Telescope Results. III. Imaging of the Galactic Center Supermassive Black Hole [PDF]

open access: yesAstrophysical Journal Letters, 2022
We present the first event-horizon-scale images and spatiotemporal analysis of Sgr A* taken with the Event Horizon Telescope in 2017 April at a wavelength of 1.3 mm.
Event Horizon Telescope Collaboration   +270 more
semanticscholar   +1 more source

The ngEHT’s Role in Measuring Supermassive Black Hole Spins [PDF]

open access: yesGalaxies, 2022
While supermassive black-hole masses have been cataloged across cosmic time, only a few dozen of them have robust spin measurements. By extending and improving the existing Event Horizon Telescope (EHT) array, the next-generation Event Horizon Telescope (
A. Ricarte   +4 more
semanticscholar   +1 more source

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