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

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Event Horizon Telescope (EHT) images of the horizon-scale emission around the Galactic Center supermassive black hole Sagittarius A* (Sgr A*) favor accretion flow models with a jet component. However, this jet has not been conclusively…

High Energy Astrophysical Phenomena · Physics 2024-05-13 Erandi Chavez , Sara Issaoun , Michael D. Johnson , Paul Tiede , Christian Fromm , Yosuke Mizuno

The EHT has captured a series of images of black holes. These images could provide valuable information about the gravitational environment near the event horizon. However, accurate detection and parameter estimation for candidate black…

Instrumentation and Methods for Astrophysics · Physics 2024-08-16 Yeqi Fang , Wei Hong , Jun Tao

We explore the evolution in power of black holes of all masses, and their associated jets, within the scheme of an accretion rate-dependent state transition. Below a critical value of the accretion rate all systems are assumed to undergo a…

Astrophysics · Physics 2008-11-26 Heino Falcke , Elmar Koerding , Sera Markoff

Low-luminosity active galactic nuclei (LLAGNs) represent the bulk of the AGN population in the present-day universe and they trace the low-level accreting supermassive black holes. In order to probe the accretion and jet physical properties…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-21 Rodrigo Nemmen , Thaisa Storchi-Bergmann , Michael Eracleous

Images of black holes encode both astrophysical and gravitational properties. Detecting highly-lensed features in images can differentiate between these two effects. We present an accretion disk emission model coupled to the Adaptive…

High Energy Astrophysical Phenomena · Physics 2025-02-24 Tejahni Desire , Alejandro Cárdenas-Avendaño , Andrew Chael

The dramatic relativistic jets pointing directly at us in BL Lac objects can be well modelled by bulk motion beaming of synchrotron self-Compton emission powered by a low Eddington fraction accretion flow. Nearly 500 of these AGN are seen…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Emma Gardner , Chris Done

We study the formation of the spectra in advection dominated accretion flows (ADAFs) around Kerr black holes. We use a Monte Carlo approach and fully general relativistic treatment to follow the paths of individual photons and model their…

Astrophysics · Physics 2007-05-23 A. Kurpiewski , M. Jaroszynski

The imaging fidelity of the Event Horizon Telescope (EHT) is currently determined by its sparse baseline coverage. In particular, EHT coverage is dominated by long baselines, and is highly sensitive to atmospheric conditions and loss of…

Instrumentation and Methods for Astrophysics · Physics 2019-09-04 S. Issaoun , M. D. Johnson , L. Blackburn , M. Mościbrodzka , A. Chael , H. Falcke

The centers of our galaxy and the nearby Messier 87 are known to contain supermassive black holes, which support accretion flows that radiate across the electromagnetic spectrum. Although the composition of the accreting gas is unknown, it…

High Energy Astrophysical Phenomena · Physics 2022-10-05 George N. Wong , Charles F. Gammie

The Event Horizon Telescope Collaboration (EHTC) has presented first - dynamic-range limited - images of the black hole shadows in M87 and Sgr A*. The next generation Event Horizon Telescope (ngEHT) will provide higher sensitivity and…

High Energy Astrophysical Phenomena · Physics 2023-03-14 Bidisha Bandyopadhyay , Christian Fendt , Dominik R. G. Schleicher , Javier Lagunas , Javier Pedreros , Neil M. Nagar , Felipe Agurto

Event Horizon Telescope (EHT) observations at 230 GHz have now imaged polarized emission around the supermassive black hole in M87 on event-horizon scales. This polarized synchrotron radiation probes the structure of magnetic fields and the…

High Energy Astrophysical Phenomena · Physics 2021-05-06 The Event Horizon Telescope Collaboration

At luminosities below a few percent of Eddington, accreting black holes switch to a hard spectral state which is very different from the soft blackbody-like spectral state that is found at higher luminosities. The hard state is…

Astrophysics · Physics 2009-11-10 Ramesh Narayan

The millimeter bump, as found in high-resolution multi-waveband observations of M87, most possibly comes from the synchrotron emission of thermal electrons in advection dominated accretion flow(ADAF). It is possible to constrain the…

High Energy Astrophysical Phenomena · Physics 2017-07-26 Jianchao Feng , Qingwen Wu

Black hole accretion and jet production are areas of intensive study in astrophysics. Recent work has found a relation between radio luminosity, X-ray luminosity, and black hole mass. With the assumption that radio and X-ray luminosity are…

High Energy Astrophysical Phenomena · Physics 2009-11-13 Kayhan Gultekin , Edward M. Cackett , Jon M. Miller , Tiziana Di Matteo , Sera Markoff , Douglas O. Richstone

M87 is arguably the best supermassive black hole (BH) to explore the jet and/or accretion physics due to its proximity and fruitful high-resolution multi-waveband observations. We model the multi-wavelength spectral energy distribution…

High Energy Astrophysical Phenomena · Physics 2016-10-12 Jianchao Feng , Qingwen Wu , Ru-Sen Lu

We introduce a new library of 535,194 model images of the supermassive black holes and Event Horizon Telescope (EHT) targets Sgr A* and M87*, computed by performing general relativistic radiative transfer calculations on general…

High Energy Astrophysical Phenomena · Physics 2023-02-22 Richard Qiu , Angelo Ricarte , Ramesh Narayan , George N. Wong , Andrew Chael , Daniel Palumbo

This work proposes a methodology to test phenomenologically-motivated emission processes that account for the flux and polarization distribution and global structure of the 230 GHz sources imaged by the Event Horizon Telescope (EHT):…

Context: Magnetic fields play a pivotal role in dynamics of black hole accretion flows and formation of relativistic jets. Observations by the Event Horizon Telescope (EHT) provided unprecedented insights into accretion structures near…

High Energy Astrophysical Phenomena · Physics 2026-02-04 Saurabh , Maciek Wielgus , Arman Tursunov , Andrei P. Lobanov , Razieh Emami

Recent results of the event horizon-scale images of M87* and Sagittarius A* from the Event Horizon Telescope Collaboration show that strong magnetic fields are likely present around the central black holes (BHs) in these sources.…

High Energy Astrophysical Phenomena · Physics 2025-09-19 Koushik Chatterjee , Matthew Liska , Alexander Tchekhovskoy , Sera Markoff , Ramesh Narayan
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