scholarly journals Radio emission from accreting isolated black holes in our galaxy

2019 ◽  
Vol 488 (2) ◽  
pp. 2099-2107 ◽  
Author(s):  
Daichi Tsuna ◽  
Norita Kawanaka
Keyword(s):  
Black Holes ◽  
Radio Emission ◽  
Interstellar Medium ◽  
Binary Systems ◽  
Electron Acceleration ◽  
Stellar Mass ◽  
Synchrotron Emission ◽  
Accelerated Electrons ◽  
Accretion Flow

ABSTRACT Apart from the few tens of stellar-mass black holes discovered in binary systems, an order of 108 isolated black holes (IBHs) are believed to be lurking in our Galaxy. Although some IBHs are able to accrete matter from the interstellar medium, the accretion flow is usually weak and thus radiatively inefficient, which results in significant material outflow. We study electron acceleration generated by the shock formed between this outflow and the surrounding material, and the subsequent radio synchrotron emission from accelerated electrons. By numerically calculating orbits of IBHs to obtain their spatial and velocity distributions, we estimate the number of IBHs detectable by surveys using SKA1-mid (SKA2) as ∼30 (∼700) for the most optimistic case. The SKA’s parallax measurements may accurately give their distances, possibly shedding light on the properties of the black holes in our Galaxy.

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 Populations of Stellar-mass Black Holes from Binary Systems

2019 ◽  
Vol 885 (1) ◽  
pp. 1 ◽  
Author(s):  
Grzegorz Wiktorowicz ◽  
Łukasz Wyrzykowski ◽  
Martyna Chruslinska ◽  
Jakub Klencki ◽  
Krzysztof A. Rybicki ◽  
...  
Keyword(s):  
Black Holes ◽  
Binary Systems ◽  
Stellar Mass

scholarly journals Negative dynamical friction on compact objects moving through dense gas

2020 ◽  
Vol 492 (2) ◽  
pp. 2755-2761 ◽  
Author(s):  
Andrei Gruzinov ◽  
Yuri Levin ◽  
Christopher D Matzner
Keyword(s):  
Black Holes ◽  
Binary Systems ◽  
Gaseous Medium ◽  
Stellar Mass ◽  
Compact Objects ◽  
Dense Gas ◽  
Dynamical Friction ◽  
Numerical Work ◽  
Massive Black Holes ◽  
Gas Drive

ABSTRACT An overdense wake is created by a gravitating object moving through a gaseous medium, and this wake pulls back on the object and slows it down. This is conventional dynamical friction in a gaseous medium. We argue that if the object drives a sufficiently powerful outflow, the wake is destroyed and instead an extended underdense region is created behind the object. In this case the overall gravitational force is applied in the direction of the object’s motion, producing a negative dynamical friction (NDF). Black holes in dense gas drive powerful outflows and may experience the NDF, although extensive numerical work is probably needed to demonstrate or refute this conclusively. NDF may be important for stellar-mass black holes and neutron stars inside ‘common envelopes’ in binary systems, for stellar mass black holes inside active galactic nucleus discs, or for massive black holes growing through super-Eddington accretion in early Universe.

scholarly journals Radio and X-ray detections of GX 339–4 in quiescence using MeerKAT and Swift

2020 ◽  
Vol 493 (1) ◽  
pp. L132-L137 ◽  
Author(s):  
E Tremou ◽  
S Corbel ◽  
R P Fender ◽  
P A Woudt ◽  
J C A Miller-Jones ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Active Galactic Nuclei ◽  
Binary Systems ◽  
Accretion Rate ◽  
Galactic Nuclei ◽  
Stellar Mass ◽  
X Ray ◽  
Accretion Process ◽  
Upper Limits

ABSTRACT The radio–X-ray correlation that characterizes accreting black holes at all mass scales – from stellar mass black holes in binary systems to supermassive black holes powering active galactic nuclei – is one of the most important pieces of observational evidence supporting the existence of a connection between the accretion process and the generation of collimated outflows – or jets – in accreting systems. Although recent studies suggest that the correlation extends down to low luminosities, only a handful of stellar mass black holes have been clearly detected, and in general only upper limits (especially at radio wavelengths) can be obtained during quiescence. We recently obtained detections of the black hole X-ray binary (XRB) GX 339–4 in quiescence using the Meer Karoo Array Telescope (MeerKAT) radio telescope and Swift X-ray Telescope instrument on board the Neil Gehrels Swift Observatory, probing the lower end of the radio–X-ray correlation. We present the properties of accretion and of the connected generation of jets in the poorly studied low-accretion rate regime for this canonical black hole XRB system.

scholarly journals Non-thermal radio emission from colliding-wind binaries: modelling Cyg OB2 No. 8A and No. 9

2010 ◽  
Vol 6 (S272) ◽  
pp. 638-639 ◽  
Author(s):  
Delia Volpi ◽  
Ronny Blomme ◽  
Michael De Becker ◽  
Gregor Rauw
Keyword(s):  
Synchrotron Radiation ◽  
Radio Emission ◽  
Binary Systems ◽  
Thermal Emission ◽  
Electron Acceleration ◽  
Stellar Winds ◽  
Ob Stars ◽  
High Energies ◽  
Thermal Radio ◽  
Thermal Radio Emission

AbstractSome OB stars show variable non-thermal radio emission. The non-thermal emission is due to synchrotron radiation that is emitted by electrons accelerated to high energies. The electron acceleration occurs at strong shocks created by the collision of radiatively-driven stellar winds in binary systems. Here we present results of our modelling of two colliding wind systems: Cyg OB2 No. 8A and Cyg OB2 No. 9.

scholarly journals Black holes: from stars to galaxies

2006 ◽  
Vol 2 (S238) ◽  
pp. 309-314 ◽  
Author(s):  
I. Félix Mirabel
Keyword(s):  
Black Holes ◽  
Binary Systems ◽  
Stellar Mass ◽  
Supermassive Black Holes ◽  
Intermediate Mass ◽  
X Ray ◽  
Nearby Galaxies ◽  
Intermediate Mass Black Holes

AbstractWhile until recently they were often considered as exotic objects of dubious existence, in the last decades there have been overwhelming observational evidences for the presence of stellar mass black holes in binary systems, supermassive black holes at the centers of galaxies, and possibly, intermediate-mass black holes observed as ultraluminous X-ray sources in nearby galaxies. Black holes are now widely accepted as real physical entities that play an important role in several areas of modern astrophysics.Here I review the concluding remarks of the IAU Symposium No 238 on Black Holes, with particular emphasis on the topical questions in this area of research.

scholarly journals VLA observations of the interacting-wind binary system WR 147

1999 ◽  
Vol 193 ◽  
pp. 344-345
Author(s):  
M. Eugenia Contreras ◽  
Luis F. Rodríguez
Keyword(s):  
Binary System ◽  
Radio Emission ◽  
Thermal Radiation ◽  
Binary Systems ◽  
Time Interval ◽  
Synchrotron Emission ◽  
Thermal Radio Emission ◽  
Radio Wavelength ◽  
Time Variations ◽  
Strong Winds

Wolf-Rayet stars are losing mass via their strong winds. Some of them show thermal and non-thermal radio emission and from this group some have companions forming binary systems. It has been suggested that the synchrotron emission arises from the interaction region where the winds of the two stars collide. WR 147 seems to be one of these systems, having a companion and emitting thermal as well as non-thermal radiation. Besides, it has been suggested that it has an anisotropic wind. In the present work we continue studying the WR 147 system by observing it at a radio wavelength of 3.6 cm in two different epochs. We have looked for evidence to support the idea that WR 147 is a colliding-wind binary system. We have also looked for time variations in the source during the time interval of ∼ 1.4 years separating our observations.

scholarly journals A supra-massive population of stellar-mass black holes in the globular cluster Palomar 5

2021 ◽  
Author(s):  
Mark Gieles ◽  
Denis Erkal ◽  
Fabio Antonini ◽  
Eduardo Balbinot ◽  
Jorge Peñarrubia
Keyword(s):  
Black Holes ◽  
Globular Cluster ◽  
Stellar Mass

scholarly journals The missing link in gravitational-wave astronomy

2021 ◽  
Author(s):  
Manuel Arca Sedda ◽  
Christopher P. L. Berry ◽  
Karan Jani ◽  
Pau Amaro-Seoane ◽  
Pierre Auclair ◽  
...  
Keyword(s):  
Black Holes ◽  
Gravitational Wave ◽  
Particle Physics ◽  
Cosmic Time ◽  
Compact Object ◽  
Stellar Mass ◽  
Wave Band ◽  
Binary Black Holes ◽  
Tests Of General Relativity ◽  
Binary Neutron Star

AbstractSince 2015 the gravitational-wave observations of LIGO and Virgo have transformed our understanding of compact-object binaries. In the years to come, ground-based gravitational-wave observatories such as LIGO, Virgo, and their successors will increase in sensitivity, discovering thousands of stellar-mass binaries. In the 2030s, the space-based LISA will provide gravitational-wave observations of massive black holes binaries. Between the $\sim 10$ ∼ 10 –103 Hz band of ground-based observatories and the $\sim 10^{-4}$ ∼ 1 0 − 4 –10− 1 Hz band of LISA lies the uncharted decihertz gravitational-wave band. We propose a Decihertz Observatory to study this frequency range, and to complement observations made by other detectors. Decihertz observatories are well suited to observation of intermediate-mass ($\sim 10^{2}$ ∼ 1 0 2 –104M⊙) black holes; they will be able to detect stellar-mass binaries days to years before they merge, providing early warning of nearby binary neutron star mergers and measurements of the eccentricity of binary black holes, and they will enable new tests of general relativity and the Standard Model of particle physics. Here we summarise how a Decihertz Observatory could provide unique insights into how black holes form and evolve across cosmic time, improve prospects for both multimessenger astronomy and multiband gravitational-wave astronomy, and enable new probes of gravity, particle physics and cosmology.

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