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Related papers: Accretion models for LLAGNs: Model Parameter Estim…

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We analyse the formation and evolution of the event horizon of a black hole binary merger when the black holes are charged. We find that the presence of charge influences the properties of the merger and can be useful for investigating the…

General Relativity and Quantum Cosmology · Physics 2022-04-20 D. Marín Pina , M. Orselli , D. Pica

This paper reviews our current understanding of low-luminosity AGNs (LLAGNs) in the context of the advection-dominated accretion flow. The best investigated source, the supermassive black hole in our galactic center, Sgr A*, is emphasized…

Astrophysics · Physics 2007-05-23 Feng Yuan

We explore an accretion model for low luminosity AGN (LLAGN) that attributes the low radiative output to a low mass accretion rate rather than a low radiative efficiency. In this model, electrons are assumed to drain energy from the ions as…

Astrophysics · Physics 2009-06-23 Erin J. D. Jolley , Zdenka Kuncic

Accretion onto black holes at rates above the Eddington limit has long been discussed in the context of supermassive black hole (SMBH) formation and evolution, providing a possible explanation for the presence of massive quasars at high…

Astrophysics of Galaxies · Physics 2020-01-22 Quentin Pognan , Benny Trakhtenbrot , Tullia Sbarrato , Kevin Schawinski , Caroline Bertemes

Recent interferometric observations by the Event Horizon Telescope have resolved the horizon-scale emission from sources in the vicinity of nearby supermassive black holes. Future space-based interferometers promise to measure the "photon…

General Relativity and Quantum Cosmology · Physics 2024-06-06 Alejandro Cárdenas-Avendaño , Alexandru Lupsasca , Hengrui Zhu

Numerical simulations of MHD accretion flows in the vicinity of a supermasssive black hole provide important insights to the problem of why and how systems -- such as the Galactic Center -- are underluminous and variable. To access…

Astrophysics · Physics 2009-11-13 Monika Moscibrodzka , Daniel Proga , Bozena Czerny , Aneta Siemiginowska

Observations of the black hole in the center of the Milky Way with the Event Horizon Telescope at 1.3 mm have revealed a size of the emitting region that is smaller than the size of the black-hole shadow. This can be reconciled with the…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Dimitrios Psaltis , Ramesh Narayan , Vincent L. Fish , Avery E. Broderick , Abraham Loeb , Sheperd S. Doeleman

Multi-frequency observations are a powerful tool of astrophysical investigation. Not only is data in each wavelength band providing different clues to the objects nature, but taken simultaneously, these data can reveal the mechanisms at…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Martin Tluczykont

Supermassive black holes can launch powerful jets which can be some of the most luminous multi-wavelength sources; decades after their discovery their physics and energetics are still poorly understood. The past decade has seen a dramatic…

High Energy Astrophysical Phenomena · Physics 2018-11-07 M. Lucchini , S. Markoff , P. Crumley , F. Krauß , R. M. T. Connors

Since black holes are `black', methods of their identification must necessarily be indirect. Due to very special boundary condition on the horizon, the advective flow behaves in a particular way, which includes formation of centrifugal…

Astrophysics · Physics 2009-10-31 S. K. Chakrabarti

Observations of supermassive black holes by the Event Horizon Telescope reveal significant inhomogeneities, most likely related to density and magnetic field perturbations. To model these features, we conduct high-resolution 2D…

General Relativity and Quantum Cosmology · Physics 2026-03-24 Giuseppe Ficarra , Michele Arcuri , Rita Megale , Sergio Servidio

We present predictions for the evolution of radio emission from Active Galactic Nuclei (AGNs). We use a model that follows the evolution of Supermassive Black Hole (SMBH) masses and spins, within the latest version of the GALFORM…

Astrophysics of Galaxies · Physics 2020-01-08 Andrew J. Griffin , Cedric G. Lacey , Violeta Gonzalez-Perez , Claudia del P. Lagos

The Event Horizon Telescope recently observed the first shadow of a black hole. Images like this can potentially be used to test or constrain theories of gravity and deepen the understanding in plasma physics at event horizon scales, which…

High Energy Astrophysical Phenomena · Physics 2020-05-28 Jeffrey van der Gucht , Jordy Davelaar , Luc Hendriks , Oliver Porth , Hector Olivares , Yosuke Mizuno , Christian M. Fromm , Heino Falcke

Accretion disks around stellar-mass black holes offer unique opportunities to study the fundamental physics of standard thin disks, super-Eddington disks, and structure that may be connected to flux variability. These local analogues of…

High Energy Astrophysical Phenomena · Physics 2019-03-12 J. M. Miller , D. Barret , E. Cackett , M. Diaz Trigo , C. Done , E. Gallo , J. Kaastra , C. Motch , C. Pinto , G. Ponti , N. Webb , A. Zoghbi

The jet in active galactic nuclei (AGN) is a key ingredient in understanding the co-evolution of galaxies and their central supermassive black holes (SMBHs). Unfortunately, the mechanism of jet launching and collimation is still elusive.…

High Energy Astrophysical Phenomena · Physics 2021-11-29 Su Yao , Xiaolong Yang , Minfeng Gu , Tao An , Jun Yang , Luis C. Ho , Xiang Liu , Ran Wang , Xue-Bing Wu , Weimin Yuan

We summarize results from a survey of radiation-dominated black hole accretion flows across a wide range of mass accretion rates, as well as two values of black hole spin and initial magnetic field geometry. These models apply an algorithm…

High Energy Astrophysical Phenomena · Physics 2025-09-16 Lizhong Zhang , James M. Stone , Patrick D. Mullen , Shane W. Davis , Yan-Fei Jiang , Christopher J. White

It has long been thought that black hole accretion flows are driven by magnetohydrodynamic (MHD) turbulence, and there are now many general relativistic global simulations illustrating the dynamics of this process. However, many challenges…

High Energy Astrophysical Phenomena · Physics 2026-03-11 Chris Nagele , Julian H. Krolik , Rongrong Liu , Brooks E. Kinch , Jeremy D. Schnittman

We present and analyse quasi-simultaneous multi-epoch spectral energy distributions (SEDs) of seven reverberation-mapped AGNs for which accurate black hole mass measurements and suitable archival data are available from the 'AGN Watch'…

Astrophysics of Galaxies · Physics 2017-12-27 Ece Kilerci-Eser , Marianne Vestergaard

Very long baseline interferometry (VLBI) makes it possible to recover images of astronomical sources with extremely high angular resolution. Most recently, the Event Horizon Telescope (EHT) has extended VLBI to short millimeter wavelengths…

Instrumentation and Methods for Astrophysics · Physics 2018-02-05 Katherine L. Bouman , Michael D. Johnson , Adrian V. Dalca , Andrew A. Chael , Freek Roelofs , Sheperd S. Doeleman , William T. Freeman

The goal of this project is to construct an estimator for the masses of supermassive black holes in active galactic nuclei (AGNs) based on the broad Halpha emission line. We make use of published reverberation mapping data. We remeasure all…