scholarly journals Hot gas flows on a parsec scale in the low-luminosity active galactic nucleus NGC 3115

2019 ◽  
Vol 492 (1) ◽  
pp. 444-455
Author(s):  
Zhiyuan Yao ◽  
Zhaoming Gan
Keyword(s):  
Black Hole ◽  
Mass Flow ◽  
Density Profile ◽  
Active Galactic Nucleus ◽  
Two Dimensional ◽  
Solar Mass ◽  
Accretion Flow ◽  
Supermassive Black Hole ◽  
The Galaxy ◽  
The One

ABSTRACT NGC 3115 is known as the low-luminosity active galactic nucleus that hosts the nearest (z ∼ 0.002) billion-solar-mass supermassive black hole (∼1.5 × 109 M⊙). Its Bondi radius rB (∼3.6 arcsec) can be readily resolved with Chandra, which provides an excellent opportunity to investigate the accretion flow on to a supermassive black hole. In this paper, we perform two-dimensional hydrodynamical numerical simulations, tailored for NGC 3115, on the mass flow across the Bondi radius. Our best fittings for the density and temperature agree well with the observations of the hot interstellar medium in the centre of NGC 3115. We find that the flow properties are determined solely by the local galaxy properties in the galaxy centre: (1) stellar winds (including supernova ejecta) supply the mass and energy sources for the accreting gas; (2) similar to in the one-dimensional calculations, a stagnation radius rst ∼ 0.1 rB is also found in the two-dimensional simulations, which divides the mass flow into an inflow–outflow structure; (3) the radiatively inefficient accretion flow theory applies well inside the stagnation radius, where the gravity is dominated by the supermassive black hole and the gas is supported by rotation; (4) beyond the stagnation radius, the stellar gravity dominates the spherical-like fluid dynamics and causes the transition from a steep density profile outside to a flat density profile inside the Bondi radius.

scholarly journals Cosmic rays from the nearby starburst galaxy NGC 253: the effect of a low-luminosity active galactic nucleus

2020 ◽  
Vol 494 (2) ◽  
pp. 2109-2116 ◽  
Author(s):  
E M Gutiérrez ◽  
G E Romero ◽  
F L Vieyro
Keyword(s):  
Black Hole ◽  
Cosmic Ray ◽  
High Energy ◽  
Starburst Galaxy ◽  
Active Nucleus ◽  
Accretion Flow ◽  
Supermassive Black Hole ◽  
Cosmic Ray Acceleration ◽  
The Galaxy ◽  
Dynamo Mechanism

ABSTRACT NGC 253 is a nearby starburst galaxy in the Sculptor group located at a distance of ∼3.5 Mpc that has been suggested by some authors as a potential site for cosmic ray acceleration up to ultrahigh energies. Its nuclear region is heavily obscured by gas and dust, which prevents establishing whether or not the galaxy harbours a supermassive black hole coexisting with the starburst. Some sources have been proposed in the literature as candidates for an active nucleus. In this work, we aim at determining the implications that the presence of a supermassive black hole at the nucleus of NGC 253 might have on cosmic ray acceleration. With this aim, we model the accretion flow on to the putative active nucleus, and we evaluate the feasibility of particle acceleration by the black hole dynamo mechanism. As a by-product, we explore the potential contribution from non-thermal particles in the accretion flow to the high-energy emission of the galaxy. We found that in the three most plausible nucleus candidates, the emission of the accretion flow would inhibit the black hole dynamo mechanism. To rule out completely the influence that a putative nucleus in NGC 253 might have in cosmic ray acceleration, a better clarification concerning the true nature of the nucleus is needed.

scholarly journals The Dark Matter Halo Density Profile, Spiral Arm Morphology, and Supermassive Black Hole Mass of M33

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Marc S. Seigar
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Density Profile ◽  
Pitch Angle ◽  
Rotation Curve ◽  
Dark Matter Halo ◽  
Black Hole Mass ◽  
Supermassive Black Hole ◽  
Virial Mass ◽  
Spiral Arm

We investigate the dark matter halo density profile of M33. We find that the HI rotation curve of M33 is best described by an NFW dark matter halo density profile model, with a halo concentration of and a virial mass of . We go on to use the NFW concentration of M33, along with the values derived for other galaxies (as found in the literature), to show that correlates with both spiral arm pitch angle and supermassive black hole mass.

Radio continuum of galaxies with H2O megamaser disks

2017 ◽  
Vol 13 (S336) ◽  
pp. 139-140
Author(s):  
F. Kamali ◽  
C. Henkel ◽  
A. Brunthaler ◽  
C. M. V. Impellizzeri ◽  
K. M. Menten ◽  
...  
Keyword(s):  
Black Hole ◽  
Accretion Disk ◽  
Active Galactic Nucleus ◽  
Position Angle ◽  
Radio Continuum ◽  
Supermassive Black Hole ◽  
5 Ghz

AbstractIn our attempt to investigate the basic active galactic nucleus (AGN) paradigm requiring a centrally located supermassive black hole (SMBH), a close to Keplerian accretion disk and a jet perpendicular to its plane, we have searched for radio continuum in galaxies with H2O megamasers in their disks. We observed 18 such galaxies with the Very Large Baseline Array in C band (5 GHz, ~2 mas resolution) and we detected 5 galaxies at 8 σ or higher levels. For those sources for which the maser data is available, the positions of masers and those of the 5 GHz radio continuum sources coincide within the uncertainties, and the radio continuum is perpendicular to the maser disk’s orientation within the position angle uncertainties.

scholarly journals A strong magnetic field around the supermassive black hole at the centre of the Galaxy

Nature ◽  
2013 ◽  
Vol 501 (7467) ◽  
pp. 391-394 ◽  
Author(s):  
R. P. Eatough ◽  
H. Falcke ◽  
R. Karuppusamy ◽  
K. J. Lee ◽  
D. J. Champion ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Black Hole ◽  
Strong Magnetic Field ◽  
Supermassive Black Hole ◽  
The Galaxy

BLACK HOLE - DESTROYER

2021 ◽  
Author(s):  
Иштимер Шагалиевич Хурамшин
Keyword(s):  
Black Hole ◽  
The Other ◽  
Baryonic Matter ◽  
Evolution Of The Universe ◽  
The Galaxy ◽  
The One ◽  
The Universe

В статье обсуждается вопрос о двух противоположных функциях черной дыры. С одной стороны она является творцом для галактики, а с другой - разрушителем барионной материи. Предполагается, что эти функции заложены самой эволюцией Вселенной. Деструкция материи до фотонов в ЧД считается наиболее вероятным событием. The question of two opposite functions of a black hole is discussed. On the one hand, it is the creator for the galaxy, and on the other-the destroyer of baryonic matter. It is assumed that these functions were laid down by the evolution of the Universe itself. The destruction of matter to photons in BH is considered the most likely event.

scholarly journals Universal interferometric signatures of a black hole’s photon ring

2020 ◽  
Vol 6 (12) ◽  
pp. eaaz1310 ◽  
Author(s):  
Michael D. Johnson ◽  
Alexandru Lupsasca ◽  
Andrew Strominger ◽  
George N. Wong ◽  
Shahar Hadar ◽  
...  
Keyword(s):  
General Relativity ◽  
Black Hole ◽  
Event Horizon ◽  
Infinite Sequence ◽  
High Order ◽  
Black Hole Mass ◽  
Tests Of General Relativity ◽  
Supermassive Black Hole ◽  
The Galaxy ◽  
Self Similar

The Event Horizon Telescope image of the supermassive black hole in the galaxy M87 is dominated by a bright, unresolved ring. General relativity predicts that embedded within this image lies a thin “photon ring,” which is composed of an infinite sequence of self-similar subrings that are indexed by the number of photon orbits around the black hole. The subrings approach the edge of the black hole “shadow,” becoming exponentially narrower but weaker with increasing orbit number, with seemingly negligible contributions from high-order subrings. Here, we show that these subrings produce strong and universal signatures on long interferometric baselines. These signatures offer the possibility of precise measurements of black hole mass and spin, as well as tests of general relativity, using only a sparse interferometric array.

scholarly journals Probing the accretion disk - jet connection via instabilities in the inner accretion flow. From microquasars to quasars

2010 ◽  
Vol 6 (S275) ◽  
pp. 94-95
Author(s):  
Agnieszka Janiuk ◽  
Bożena Czerny ◽  
Monika Mościbrodzka ◽  
Aneta Siemiginowska
Keyword(s):  
Black Hole ◽  
Accretion Disk ◽  
Radiation Pressure ◽  
Duty Cycle ◽  
Thermal Instability ◽  
Accretion Flow ◽  
Supermassive Black Hole ◽  
Complex Morphology ◽  
Hydrogen Ionization ◽  
Jet Axis

AbstractWe present various instability mechanisms in the accreting black hole systems which might indicate at the connection between the accretion disk and jet. The jets observed in microquasars can have a peristent or blobby morphology. Correlated with the accretion luminosity, this might provide a link to the cyclic outbursts of the disk. Such duty-cycle type of behaviour on short timescales results from the thermal instability caused by the radiation pressure domination. The same type of instability may explain the cyclic radioactivity of the supermassive black hole systems. The somewhat longer timescales are characteristic for the instability caused by the partial hydrogen ionization. The distortions of the jet direction and complex morphology of the sources can be caused by precession of the disk-jet axis.

scholarly journals RESOLVING THE BONDI ACCRETION FLOW TOWARD THE SUPERMASSIVE BLACK HOLE OF NGC 3115 WITH CHANDRA

2011 ◽  
Vol 736 (1) ◽  
pp. L23 ◽  
Author(s):  
Ka-Wah Wong ◽  
Jimmy A. Irwin ◽  
Mihoko Yukita ◽  
Evan T. Million ◽  
William G. Mathews ◽  
...  
Keyword(s):  
Black Hole ◽  
Accretion Flow ◽  
Supermassive Black Hole

scholarly journals The Brightest Point in Accretion Disk and Black Hole Spin: Implication to the Image of Black Hole M87*

Universe ◽  
2019 ◽  
Vol 5 (8) ◽  
pp. 183 ◽  
Author(s):  
Vyacheslav I. Dokuchaev ◽  
Natalia O. Nazarova
Keyword(s):  
Black Hole ◽  
Event Horizon ◽  
Accretion Disk ◽  
Disk Model ◽  
Dark Region ◽  
High Resolution Image ◽  
Supermassive Black Hole ◽  
Black Hole Spin ◽  
The Galaxy ◽  
Expected Position

We propose the simple new method for extracting the value of the black hole spin from the direct high-resolution image of black hole by using a thin accretion disk model. In this model, the observed dark region on the first image of the supermassive black hole in the galaxy M87, obtained by the Event Horizon Telescope, is a silhouette of the black hole event horizon. The outline of this silhouette is the equator of the event horizon sphere. The dark silhouette of the black hole event horizon is placed within the expected position of the black hole shadow, which is not revealed on the first image. We calculated numerically the relation between the observed position of the black hole silhouette and the brightest point in the thin accretion disk, depending on the black hole spin. From this relation, we derive the spin of the supermassive black hole M87*, a = 0.75 ± 0.15 .

scholarly journals The central cluster and X-ray emission from Sgr A*

2006 ◽  
Vol 2 (S238) ◽  
pp. 347-348
Author(s):  
Robert F. Coker ◽  
Julian M. Pittard
Keyword(s):  
Black Hole ◽  
Stellar Winds ◽  
Solar Mass ◽  
Hydrodynamic Simulations ◽  
X Ray ◽  
Central Cluster ◽  
The Galaxy ◽  
Early Type Stars ◽  
Sgr A ◽  
Hydrodynamic Data

AbstractAt the centre of the Milky Way is Sgr A*, a putative 3 million solar mass black hole with an observed luminosity that is orders of magnitude smaller than that expected from simple accretion theories. The number density of early-type stars is quite high near Sgr A*, so the ensemble of their stellar winds has a significant impact on the black hole's environment.We present results of 3D hydrodynamic simulations of the accretion of stellar winds onto Sgr A*. Using the LANL/SAIC code, RAGE, we model the central arc-second of the Galaxy, including the central cluster stars (the S-stars) with orbits and wind parameters that match observations. A significant fraction of the winds from the S stars becomes gravitationally bound to the black hole and thus could provide enough hot gas to produce the X-ray emission seen by Chandra. We perform radiative transfer calculations on the 3D hydrodynamic data cubes and present the resulting synthetic X-ray spectrum.

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