Results 41 to 50 of about 34,507 (229)

The GLEAMing of the first supermassive black holes

Publications of the Astronomical Society of Australia, 2020
AbstractWe present the results of a new selection technique to identify powerful ($L_{\rm 500\,MHz} \gt 10^{27}\,\text{WHz}^{-1}$) radio galaxies towards the end of the Epoch of Reionisation. Our method is based on the selection of bright radio sources showing radio spectral curvature at the lowest frequency (${\sim}100\,\text{MHz}$) combined with the ...
Guillaume Drouart, Nick Seymour, Tim J. Galvin, Jose Afonso, Joseph R. Callingham, Carlos De Breuck, Melanie Johnston-Hollitt, Anna D. Kapińska, Matthew D. Lehnert, Joël Vernet   +9 more
openaire   +6 more sources

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

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
core   +2 more sources

Supermassive black holes then and now [PDF]

AIP Conference Proceedings, 1998
7 pages, to appear in The Proceedings of the Second International LISA Symposium on Graviational Waves, ed.
openaire   +5 more sources

Hierarchical build-up of galactic bulges and the merging rate of supermassive binary black holes

, 2003
The hierarchical build-up of galactic bulges should lead to the build-up of present-day supermassive black holes by a mixture of gas accretion and merging of supermassive black holes.
Begelman M, Begelman M, Bender P, Bernardi M, Gerssen J, Haehnelt M G, Haehnelt M G, Haehnelt M G, Martin G Haehnelt, Milosavljevic M, Soltan A, Yu Q   +11 more
core   +1 more source

Supermassive Black Hole Feedback

, 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, Nagai, Daisuke, Zhuravleva, Irina, Brummel-Smith, Corey, Li, Yuan, Hodges-Kluck, Edmund, Yang, Hsiang-Yi Karen, Basu, Kaustuv, Chluba, Jens, Churazov, Eugene, Donahue, Megan, Fabian, Andrew, Faucher-Giguère, Claude-André, GASPARI, MASSIMO, Hlavacek-Larrondo, Julie, McDonald, Michael, McNamara, Brian, Nulsen, Paul, Mroczkowski, Tony, Mushotzky, Richard, Reynolds, Christopher, Vikhlinin, Alexey, Voit, Mark, Werner, Norbert, ZuHone, John, Zweibel, Ellen   +25 more
openaire   +3 more sources

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
openaire   +4 more sources

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
doaj   +1 more source

Primordial black holes as dark matter candidates

SciPost Physics Lecture Notes, 2022
We review the formation and evaporation of primordial black holes (PBHs) and their possible contribution to dark matter. Various constraints suggest they could only provide most of it in the mass windows $10^{17}$ - $10^{23}\,$g or $10$ - $10^{2}\,M_ ...
Bernard Carr, Florian Kuhnel
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
core   +1 more source