Results 11 to 20 of about 132,127 (279)

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

open access: yesThe Astrophysical 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 ...
Zaven Arzoumanian   +78 more
doaj   +2 more sources

Leptonic and Hadronic Radiative Processes in Supermassive-Black-Hole Jets [PDF]

open access: yesGalaxies, 2020
Supermassive black holes lying in the center of galaxies can launch relativistic jets of plasma along their polar axis. The physics of black-hole jets is a very active research topic in astrophysics, owing to the fact that many questions remain open on ...
Matteo Cerruti
doaj   +2 more sources

Formation of Supermassive Black Hole Seeds [PDF]

open access: yesPublications of the Astronomical Society of Australia, 2016
The 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
M. Latif, A. Ferrara
semanticscholar   +6 more sources

The birth of a supermassive black hole binary [PDF]

open access: yesMonthly Notices of the Royal Astronomical Society, 2017
We study the dynamical evolution of supermassive black holes, in the late stage of galaxy mergers, from kpc to pc scales. In particular, we capture the formation of the binary, a necessary step before the final coalescence, and trace back the main ...
H. Pfister   +5 more
semanticscholar   +5 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

Implications for the supermassive black hole binaries from the NANOGrav 15-year data set [PDF]

open access: yesScience China Physics Mechanics and Astronomy, 2023
Several pulsar timing array (PTA) collaborations, including NANOGrav, EPTA, PPTA, and CPTA, have announced the evidence for a stochastic signal consistent with a stochastic gravitational wave background (SGWB).
Yanfeng Bi   +3 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

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