Results 11 to 20 of about 182 (138)
A supermassive binary black hole in the quasar 3C 345 [PDF]
Astronomy & Astrophysics, 2005 Radio loud active galactic nuclei present a remarkable variety of signs indicating the presence of periodical processes possibly originating in binary systems of supermassive black holes, in which orbital motion and precession are ultimately responsible for the observed broad-band emission variations, as well as for the morphological and kinematic ...
Lobanov, A. P., Roland, J.
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THE ORIGINS AND THE EARLY EVOLUTION OF QUASARS AND SUPERMASSIVE BLACK HOLES [PDF]
The Eleventh Marcel Grossmann Meeting, 2008 The relationship between galaxies and supermassive black holes (SMBH) found in their cores plays a key role in the formation and evolution of both of these major constituents of the universe, as well as the evolution of the intergalactic medium. Neither can be fully understood on their own, and studies of galaxy and SMBH co-formation and co-evolution ...
Djorgovski, S. +4 more
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Gauging the effect of supermassive black holes feedback on quasar host galaxies [PDF]
Monthly Notices of the Royal Astronomical Society, 2021 ABSTRACT In order to gauge the role that active galactic nuclei play in the evolution of galaxies via the effect of kinetic feedback in nearby QSO 2’s (z ∼ 0.3), we observed eight such objects with bolometric luminosities $L_{bol} \sim 10^{46}\rm {erg\, s^{-1}}$ using Gemini Multi-Object Spectrograph-integral field units.
B Dall’Agnol de Oliveira +8 more
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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
Quasar and Supermassive Black Hole Evolution [PDF]
Proceedings of the International Astronomical Union, 2009 AbstractWe present results from statistical analysis of the largest quasar surveys currently in existence: the Sloan Digital Sky Survey (SDSS), the 2dF QSO Redshift Survey (2QZ), and the 2dF-SDSS LRG and QSO (2SLAQ) Survey. The quasar luminosity function shows highly significant (>99.9%) evidence of downsizing: the number density of faint quasars ...
Scott M. Croom, Stephen Fine
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Extreme accretion events: TDEs and changing‐look AGN
Astronomische Nachrichten, Volume 344, Issue 4, May 2023., 2023 Abstract We present a review of the topics of X‐ray stellar tidal disruption events (TDEs) and changing‐look active galactic nuclei (AGN). Stars approaching a supermassive black hole (SMBH) can be tidally disrupted and accreted. TDEs were first discovered in the X‐ray regime and appear as luminous, giant‐amplitude flares from inactive galaxies.
S. Komossa, D. Grupe
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Astronomische Nachrichten, Volume 344, Issue 4, May 2023., 2023 Abstract The non‐linear correlation between the UV and X‐ray emission observed in active galactic nuclei remains a puzzling question that challenges accretion models. While the UV emission originates from the cold disk, the X‐ray emission is emitted by a hot corona whose physical characteristics and geometry are still highly debated.
S. Barnier +3 more
wiley +1 more source
The road toward imaging a black hole: A personal perspective
Natural Sciences, Volume 2, Issue 4, October 2022., 2022 The article describes the authors personal journey towards developig the Event Horizon Telescope and the first image of a black hole. Left: predcition made by the author and collaborators proposing the black hole imaging in 2000. Right: the two images observed and published by the Event Horizon Telescope in 2019 and 2022.
Heino Falcke
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Unconventional reconciliation path for quantum mechanics and general relativity
IET Quantum Communication, Volume 3, Issue 2, Page 99-111, June 2022., 2022 Abstract Physics in general is successfully governed by quantum mechanics at the microscale and principles of relativity at the macroscale. Any attempts to unify them using conventional methods have somewhat remained elusive for nearly a century up to the present stage. Here, a classical gedanken experiment of electron‐wave diffraction of a single slit
Samuel Polopa Yuguru
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A Recoiling Supermassive Black Hole in the Quasar SDSS J092712.65+294344.0? [PDF]
The Astrophysical Journal, 2008 We present SDSSJ092712.65+294344.0 as the best candidate to date for a recoiling supermassive black hole (SMBH). SDSSJ0927+2943 shows an exceptional optical emission-line spectrum with two sets of emission lines: one set of very narrow emission lines, and a second set of broad Balmer and broad high-ionization forbidden lines which are blueshifted by ...
Komossa, S., Zhou, H., Lu, H.
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