Determination of supermassive black hole spins in local active galactic nuclei

2021 ◽  
Author(s):  
Mikhail Yu. Piotrovich ◽  
Stanislava D. Buliga ◽  
Tinatin M. Natsvlishvili
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Supermassive Black Hole

Determination of supermassive black hole spins in active galactic nuclei

2020 ◽  
Vol 35 (02n03) ◽  
pp. 2040054
Author(s):  
M. Yu. Piotrovich ◽  
V. L. Afanasiev ◽  
S. D. Buliga ◽  
T. M. Natsvlishvili
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Active Galactic Nuclei ◽  
Accretion Disk ◽  
Galactic Nuclei ◽  
Supermassive Black Holes ◽  
Disk Model ◽  
Supermassive Black Hole

Based on spectropolarimetry for a number of active galactic nuclei in Seyfert 1 type galaxies observed with the 6-m BTA telescope, we have estimated the spins of the supermassive black holes at the centers of these galaxies. We have determined the spins based on the standard Shakura-Sunyaev accretion disk model. More than 70% of the investigated active galactic nuclei are shown to have Kerr supermassive black holes with a dimensionless spin greater than 0.9.

2.9. Microlens mapping of disks in active galactic nuclei

1998 ◽  
Vol 184 ◽  
pp. 75-76 ◽  
Author(s):  
A. Yonehara ◽  
S. Mineshige ◽  
J. Fukue ◽  
M. Umemura ◽  
E.L. Turner
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Accretion Disk ◽  
Central Region ◽  
Galactic Nuclei ◽  
Direct Information ◽  
Supermassive Black Hole ◽  
Disk Size

Generally, it is believed that there is a supermassive black hole and a surrounding accretion disk in a central region of active galactic nuclei (AGN). However, it is quite difficult to obtain direct information about the center of AGN, because the accretion disk size is far too small to resolve.

scholarly journals Estimating supermassive black hole masses in active galactic nuclei using polarization of broad Mg ii, H α, and H β lines

2020 ◽  
Vol 497 (3) ◽  
pp. 3047-3054
Author(s):  
Đorđe Savić ◽  
L Č Popović ◽  
E Shablovinskaya ◽  
V L Afanasiev
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Three Dimensional ◽  
Polarization Plane ◽  
Galactic Nuclei ◽  
Position Angle ◽  
Broad Line ◽  
Keplerian Motion ◽  
Supermassive Black Hole ◽  
Polarization Mechanism

ABSTRACT For type-1 active galactic nuclei (AGNs) for which the equatorial scattering is the dominant broad-line polarization mechanism, it is possible to measure the supermassive black hole (SMBH) mass by tracing the Keplerian motion across the polarization plane position angle φ. So far, this method has been used for 30 objects but only for H α emission line. We explore the possibilities of this method for determining SMBH masses using polarization in broad emission lines by applying it for the first time to Mg ii λ2798 Å spectral line. We use three-dimensional (3-D) Monte Carlo radiative transfer code stokes for simultaneous modelling of equatorial scattering of H α, H β, and Mg ii lines. We included vertical inflows and outflows in the Mg ii broad-line region (BLR). We find that polarization states of H α and H β lines are almost identical and SMBH-mass estimates differ by 7 per cent. For Mg ii line, we find that φ exhibits an additional ‘plateau’ with a constant φ, which deviates than the profiles expected for pure Keplerian motion. SMBH-mass estimates using Mg ii line are higher by up to 35 per cent than those obtained from H α and H β lines. Our model shows that for vertical inflows and outflows in the BLR that are higher or comparable to the Keplerian velocity, this method can be applied as a first approximation for obtaining SMBH mass.

scholarly journals Conceptual Analogies Between Multi-Scale Feeding and Feedback Cycles in Supermassive Black Hole and Cancer Environments

2021 ◽  
Vol 11 ◽  
Author(s):  
Matteo Santoni ◽  
Francesco Tombesi ◽  
Alessia Cimadamore ◽  
Rodolfo Montironi ◽  
Francesco Piva
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Human Cancer ◽  
Galactic Nuclei ◽  
Interdisciplinary Approach ◽  
Cancer Microenvironment ◽  
Unified Theory ◽  
Multi Scale ◽  
Supermassive Black Hole

Adopting three physically-motivated scales (“micro” – “meso” – “macro”, which refer to mpc – kpc – Mpc, respectively) is paramount for achieving a unified theory of multiphase active galactic nuclei feeding and feedback, and it represents a keystone for astrophysical simulations and observations in the upcoming years. In order to promote this multi-scale idea, we have decided to adopt an interdisciplinary approach, exploring the possible conceptual similarities between supermassive black hole feeding and feedback cycles and the dynamics occurring in human cancer microenvironment.

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