Results 41 to 50 of about 264,425 (308)
Multiwavelength astrophysics of the blazar OJ 287 and the project MOMO
Astronomische Nachrichten, Volume 344, Issue 4, May 2023., 2023 Abstract We are carrying out the densest and longest multiyear, multiwavelength monitoring project of OJ 287 ever done. The project MOMO (Multiwavelength Observations and Modeling of OJ 287) covers wavelengths from the radio to the high‐energy regime. A few selected observations are simultaneous with those of the Event Horizon Telescope (EHT).
S. Komossa +21 more
wiley +1 more source
The Case for the Fundamental MBH-σ Relation
Frontiers in Physics, 2020 Strong scaling relations between host galaxy properties (such as stellar mass, bulge mass, luminosity, effective radius etc) and their nuclear supermassive black hole's mass point toward a close co-evolution.
Christopher Marsden +3 more
doaj +1 more source
Measuring Distance and Properties of the Milky Way’s Central Supermassive Black Hole with Stellar Orbits [PDF]
, 2008 We report new precision measurements of the properties of our Galaxy’s supermassive black hole. Based on astrometric (1995-2007) and radial velocity (RV; 2000-2007) measurements from the W. M.
A. Ghez +14 more
semanticscholar +1 more source
EHT Constraint on the Ultralight Scalar Hair of the M87 Supermassive Black Hole [PDF]
Universe, 2019 Hypothetical ultralight bosonic fields will spontaneously form macroscopic bosonic halos around Kerr black holes, via superradiance, transferring part of the mass and angular momentum of the black hole into the halo.
P. Cunha, C. Herdeiro, E. Radu
semanticscholar +1 more source
Searching for overlooked TDEs in the 4XMM catalogue
Astronomische Nachrichten, Volume 344, Issue 4, May 2023., 2023 Abstract Tidal disruption events (TDEs) are usually discovered as bright transients, either in the X‐ray or optical/UV band. These events are often characterized by a “super‐soft” emission in the X‐ray band, which has not been observed in any other extragalactic source, with few exceptions (novae and supersoft active galactic nuclei, AGN), which can ...
Andrea Sacchi +2 more
wiley +1 more source
Winds in ultraluminous X‐ray sources: New challenges
Astronomische Nachrichten, Volume 344, Issue 4, May 2023., 2023 Abstract Ultraluminous X‐ray sources (ULXs) are extreme X‐ray binaries shining above 1039 erg/s, in most cases as a consequence of super‐Eddington accretion onto neutron stars and stellar‐mass black holes accreting above their Eddington limit. This was understood after the discovery of coherent pulsations, cyclotron lines, and powerful winds.
C. Pinto, P. Kosec
wiley +1 more source
Visible Shapes of Black Holes M87* and SgrA*
Universe, 2020 We review the physical origins for possible visible images of the supermassive black hole M87* in the galaxy M87 and SgrA* in the Milky Way Galaxy. The classical dark black hole shadow of the maximal size is visible in the case of luminous background ...
Vyacheslav I. Dokuchaev +1 more
doaj +1 more source
Two-temperature, Magnetically Arrested Disc simulations of the jet from the supermassive black hole in M87 [PDF]
Monthly notices of the Royal Astronomical Society, 2018 We present two-temperature, radiative general relativistic magnetohydrodynamic simulations of Magnetically Arrested Discs (MAD) that launch powerful relativistic jets.
A. Chael, R. Narayan, Michael D. Johnson
semanticscholar +1 more source
Fourier spectral‐timing techniques for the study of accreting black holes
Astronomische Nachrichten, Volume 344, Issue 4, May 2023., 2023 Abstract The X‐ray signal from active galactic nuclei and black hole (BH) X‐ray binaries is highly variable on a range of timescales. This variability can be exploited to map the region of interest close to the BH, which is far too small to directly image for all but two BHs in the Universe.
Adam Ingram
wiley +1 more source
The 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