Results 61 to 70 of about 166,156 (289)

A supermassive black hole awakes [PDF]

Science, 2017
Active Galaxies Every large galaxy hosts a supermassive black hole at its center, which grows by consuming passing gas or stars. Most are quiescent, but when the black hole is feeding, an accretion disk forms, causing the galaxy nucleus to shine brightly as a quasar. Gezari et al.
openaire   +2 more sources

Leptonic and Hadronic Radiative Processes in Supermassive-Black-Hole Jets

Galaxies, 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   +1 more source

Black Holes, Mergers, and the Entropy Budget of the Universe

, 2002
Vast amounts of entropy are produced in black hole formation, and the amount of entropy stored in supermassive black holes at the centers of galaxies is now much greater than the entropy free in the rest of the universe.
Abrahams A M (Binary Black Hole Grand Challenge Alliance Collaboration), Anninos P, Anninos P, Barr S M, Baumgarte T W, Flanagan E E, Holman R, Janka H T, Kamionkowski M, Macchetto E D, Postnov K A, Rees M J, Saijo M, Shibata M, Silk J, Starkman G D, Thomas W Kephart, Tinto M, Totani T, Valageas P, Wilson J R, Y Jack Ng, Yungelson L   +22 more
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The Blazar PG 1553+113 as a Binary System of Supermassive Black Holes [PDF]

, 2018
The BL Lac PG 1553+113 has been continuously monitored in gamma-rays with Fermi-LAT for over 9 years. Its updated light curve now includes five iterations of a main pattern comprising a high peak and a longer trough, with a period .
M. Tavani, A. Cavaliere, P. Munar-Adrover, A. Argan   +3 more
semanticscholar   +1 more source

Gravitational lensing by a Horndeski black hole

European Physical Journal C: Particles and Fields, 2017
In this article we study gravitational lensing by non-rotating and asymptotically flat black holes in Horndeski theory. By adopting the strong deflection limit, we calculate the deflection angle, from which we obtain the positions and the magnifications ...
Javier Badía, Ernesto F. Eiroa
doaj   +1 more source

Primordial seeds of supermassive black holes

, 2012
Supermassive black holes exist in the centers of galaxies, including Milky Way, but there is no compelling theory of their formation. Furthermore, observations of quasars imply that supermassive black holes have already existed at some very high ...
Kawasaki, Masahiro, Kusenko, Alexander, Yanagida, Tsutomu T.   +2 more
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Ram-pressure feeding of supermassive black holes [PDF]

Nature, 2017
When a supermassive black hole at the centre of a galaxy accretes matter, it gives rise to a highly energetic phenomenon: an active galactic nucleus. Numerous physical processes have been proposed to account for the funnelling of gas towards the galactic
B. Poggianti, Y. Jaffé, A. Moretti, M. Gullieuszik, M. Radovich, S. Tonnesen, J. Fritz, D. Bettoni, B. Vulcani, G. Fasano, C. Bellhouse, G. Hau, A. Omizzolo   +12 more
semanticscholar   +1 more source

First Detection of an Overmassive Black Hole Galaxy UHZ1: Evidence for Heavy Black Hole Seed Formation from Direct Collapse

The Astrophysical Journal Letters, 2023
The recent Chandra-JWST discovery of a quasar in the z ≈ 10.1 galaxy UHZ1 reveals that accreting supermassive black holes were already in place 470 million years after the Big Bang. The Chandra X-ray source detected in UHZ1 is a Compton-thick quasar with
Priyamvada Natarajan, Fabio Pacucci, Angelo Ricarte, Ákos Bogdán, Andy D. Goulding, Nico Cappelluti   +5 more
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A Radio Census of Binary Supermassive Black Holes

, 2010
Using archival VLBI data for 3114 radio-luminous active galactic nuclei, we searched for binary supermassive black holes using a radio spectral index mapping technique which targets spatially resolved, double radio-emitting nuclei.
Beasley, Begelman, Boroson, Britzen, Colpi, Comerford, De Lucia, De Propris, Decarli, Detweiler, Dunlop, Enoki, Ferrarese, Fomalont, Frank, Giovannini, Gualandris, Haring, Jaffe, Jenet, Komossa, Komossa, Kovalev, Lacey, Lister, Lovell, Mason, Mauch, McLure, Merritt, Merritt, Myers, Owsianik, Padovani, Peterson, Petrov, Petrov, Petrov, Pollack, Rajagopal, Rodriguez, S. Burke-Spolaor, Saripalli, Sault, Sesana, Sesana, Slee, Springel, Sudou, Valtonen, Volonteri, Walker, Wang, Wen, Wilkinson, Wyithe, Yu   +56 more
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Supermassive black holes and their environments [PDF]

Monthly Notices of the Royal Astronomical Society, 2008
We make use of the first high--resolution hydrodynamic simulations of structure formation which self-consistently follows the build up of supermassive black holes introduced in Di Matteo et al. (2007) to investigate the relation between black holes (BH), host halo and large--scale environment.
Colberg, Joerg M., Di Matteo, Tiziana
openaire   +2 more sources