Results 31 to 40 of about 5,650 (230)

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

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   +1 more source

Supermassive black holes in BCGs [PDF]

open access: yesProceedings of the International Astronomical Union, 2006
AbstractWe observed a sample of three Brightest Cluster Galaxies (BCGs), Abell 1836-BCG, Abell 2052-BCG, and Abell 3565-BCG, with the Advanced Camera for Surveys (ACS) and the Imaging Spectrograph (STIS) on board the Space Telescope. For each target galaxy we obtained high-resolution spectroscopy of the Hα and [N II] λ6583 emission lines at three slit ...
Bontá, E. D.   +5 more
openaire   +3 more sources

Growth of Supermassive Black Holes, Galaxy Mergers and Supermassive Binary Black Holes [PDF]

open access: yesProceedings of the International Astronomical Union, 2015
AbstractThe study of galaxy mergers and supermassive binary black holes (SMBBHs) is central to our understanding of the galaxy and black hole assembly and (co-)evolution at the epoch of structure formation and throughout cosmic history. Galaxy mergers are the sites of major accretion episodes, they power quasars, grow supermassive black holes (SMBHs ...
Komossa, S., Baker, J. G., Liu, F. K.
openaire   +2 more sources

Supermassive black hole demographics: evading M − σ [PDF]

open access: yesMonthly Notices of the Royal Astronomical Society, 2019
We consider black hole - galaxy coevolution using simple analytic arguments. We focus on the fact that several supermassive black holes are known with masses significantly larger than suggested by the $M - $ relation, sometimes also with rather small stellar masses.
Andrew King, Rebecca Nealon
openaire   +4 more sources

Gravitational lensing by a quantum deformed Schwarzschild black hole

open access: yesEuropean Physical Journal C: Particles and Fields, 2021
We investigate the weak and strong deflection gravitational lensing by a quantum deformed Schwarzschild black hole and find their observables. These lensing observables are evaluated and the detectability of the quantum deformation is assessed, after ...
Xu Lu, Yi Xie
doaj   +1 more source

DYNAMICAL FRICTION AROUND SUPERMASSIVE BLACK HOLES [PDF]

open access: yesThe Astrophysical Journal, 2011
The density of stars in galactic bulges is often observed to be flat or slowly rising inside the influence radius of the supermassive black hole (SMBH). Attributing the dynamical friction force to stars moving more slowly than the test body, as is commonly done, is likely to be a poor approximation in such a core since there are no stars moving more ...
Antonini, Fabio, Merritt, David
openaire   +3 more sources

Key Science Goals for the Next-Generation Event Horizon Telescope

open access: yesGalaxies, 2023
The Event Horizon Telescope (EHT) has led to the first images of a supermassive black hole, revealing the central compact objects in the elliptical galaxy M87 and the Milky Way.
Michael D. Johnson   +44 more
doaj   +1 more source

Gravitational ringing and superradiant instabilities of the Kerr-like black holes in a dark matter halo

open access: yesEuropean Physical Journal C: Particles and Fields, 2023
Supermassive black holes from the center of galaxy may be immersed in a dark matter halo. This dark matter halo may form a “cusp” structure around the black hole and disappear at a certain distance from the black hole.
Dong Liu   +4 more
doaj   +1 more source

Black Hole Images as Tests of General Relativity: Effects of Spacetime Geometry

open access: yesThe Astrophysical Journal, 2023
The images of supermassive black holes surrounded by optically thin, radiatively inefficient accretion flows, like those observed with the Event Horizon Telescope, are characterized by a bright ring of emission surrounding the black hole shadow.
Ziri Younsi   +2 more
doaj   +1 more source

Strong deflection lensing by a Lee–Wick black hole

open access: yesPhysics Letters B, 2017
We study strong deflection gravitational lensing by a Lee–Wick black hole, which is a non-singular black hole generated by a high derivative modification of Einstein–Hilbert action.
Shan-Shan Zhao, Yi Xie
doaj   +1 more source

Home - About - Disclaimer - Privacy