scholarly journals Multiwavelength Emission from Magnetically Arrested Disks around Isolated Black Holes

2021 ◽  
Vol 922 (1) ◽  
pp. L15
Author(s):  
Shigeo S. Kimura ◽  
Kazumi Kashiyama ◽  
Kenta Hotokezaka
Keyword(s):  
Black Holes ◽  
Synchrotron Radiation ◽  
Interstellar Medium ◽  
Neutron Stars ◽  
White Dwarfs ◽  
Gamma Ray ◽  
Optical Signals ◽  
X Ray ◽  
Nonthermal Electrons

Abstract We discuss the prospects for identifying the nearest isolated black holes (IBHs) in our Galaxy. IBHs accreting gas from the interstellar medium likely form magnetically arrested disks (MADs). We show that thermal electrons in the MADs emit optical signals through the thermal synchrotron process while nonthermal electrons accelerated via magnetic reconnections emit a flat-spectrum synchrotron radiation in the X-ray to MeV gamma-ray ranges. The Gaia catalog will include at most a thousand IBHs within ≲1 kpc that are distributed on and around the cooling sequence of white dwarfs (WDs) in the Hertzsprung–Russell diagram. These IBH candidates should also be detected by eROSITA, with which they can be distinguished from isolated WDs and neutron stars. Follow-up observations with hard X-ray and MeV gamma-ray satellites will be useful to unambiguously identify IBHs.

scholarly journals Accretion onto Relativistic Objects

1974 ◽  
Vol 64 ◽  
pp. 194-212
Author(s):  
M. J. Rees
Keyword(s):  
Black Holes ◽  
Interstellar Medium ◽  
Neutron Stars ◽  
Binary Systems ◽  
Compact Object ◽  
Stellar Mass ◽  
Supermassive Black Holes ◽  
Compact Objects ◽  
X Ray ◽  
Intergalactic Space

The physics of spherically symmetrical accretion onto a compact object is briefly reviewed. Neither neutron stars nor stellar-mass black holes are likely to be readily detectable if they are isolated and accreting from the interstellar medium. Supermassive black holes in intergalactic space may however be detectable. The effects of accretion onto compact objects in binary systems are then discussed, with reference to the phenomena observed in variable X-ray sources.

scholarly journals FUNDAMENTAL PHYSICS FROM BLACK HOLES, NEUTRON STARS AND GAMMA-RAY BURSTS

2011 ◽  
Vol 20 (10) ◽  
pp. 1797-1872 ◽  
Author(s):  
REMO RUFFINI
Keyword(s):  
Black Holes ◽  
Neutron Stars ◽  
White Dwarfs ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Theoretical Physics ◽  
Fundamental Physics

Gamma-ray bursts (GRBs) and supernovae (SNe) bring new perspectives to the study of neutron stars and white dwarfs, as well as opening new branches of theoretical physics and astrophysics.

scholarly journals A binary population synthesis study on gravitational wave sources

2015 ◽  
Vol 11 (A29B) ◽  
pp. 365-366
Author(s):  
Liu Jinzhong ◽  
Zhang Yu
Keyword(s):  
Black Holes ◽  
Neutron Stars ◽  
Gravitational Wave ◽  
Gamma Ray ◽  
Theoretical Study ◽  
Compact Objects ◽  
Population Synthesis ◽  
Observational Astronomy ◽  
X Ray ◽  
X Ray Binaries

AbstractGravitational waves (GW) are a natural consequence of Einstein's theory of gravity (general relativity), and minute distortions of space-time. Gravitational Wave Astronomy is an emerging branch of observational astronomy which aims to use GWs to collect observational data about objects such as neutron stars and black holes, about events such as supernovae and about the early universe shortly after the big bang.This field will evolve to become an established component of 21st century multi-messenger astronomy, and will stand shoulder-to-shoulder with gamma-ray, x-ray, optical, infrared and radio astronomers in exploring the cosmos. In this paper, we state a recent theoretical study on GW sources, and present the results of our studies on the field using a binary population synthesis (BPS) approach, which was designed to investigate the formation of many interesting binary-related objects, including close double white dwarfs, AM CVn stars, ultra-compact X-ray binaries(UCXBs), double neutron stars, double stellar black holes. Here we report how BPS can be used to determine the GW radiation from double compact objects.

scholarly journals Halo/Thick Disk CVS and the Cosmic X-Ray Background

1996 ◽  
Vol 168 ◽  
pp. 543-548
Author(s):  
Jonathan E. Grindlay ◽  
Eyal Maoz
Keyword(s):  
Black Holes ◽  
Neutron Stars ◽  
Globular Clusters ◽  
White Dwarfs ◽  
Thick Disk ◽  
X Ray ◽  
Diffuse Flux ◽  
The Galaxy ◽  
X Ray Background

In a recent study (Maoz and Grindlay 1995) we have found that a number of previously recognized anomalies in the diffuse x-ray background at soft energies (~0.5-2 keV) can be understood if about 20-30% of the diffuse flux arises from a population of low luminosity sources in a thick disk or flattened halo distribution in the Galaxy. Here we summarize our results and review the arguements that these objects are not accreting neutron stars or black holes but rather white dwarfs (i.e. CVs) which may have been produced in a primordial population of disrupted globular clusters.

scholarly journals Diverse Features of the Multiwavelength Afterglows of Gamma-Ray Bursts: Natural or Special?

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
J. J. Geng ◽  
Y. F. Huang
Keyword(s):  
Black Holes ◽  
Numerical Method ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Shock Model ◽  
Reverse Shock ◽  
X Ray ◽  
Electron Positron ◽  
Forward Shock ◽  
Electron Positron Pair

The detection of optical rebrightenings and X-ray plateaus in the afterglows of gamma-ray bursts (GRBs) challenges the generic external shock model. Recently, we have developed a numerical method to calculate the dynamics of the system consisting of a forward shock and a reverse shock. Here, we briefly review the applications of this method in the afterglow theory. By relating these diverse features to the central engines of GRBs, we find that the steep optical rebrightenings would be caused by the fall-back accretion of black holes, while the shallow optical rebrightenings are the consequence of the injection of the electron-positron-pair wind from the central magnetar. These studies provide useful ways to probe the characteristics of GRB central engines.

Sign in / Sign up

Export Citation Format

Share Document