Black holes in astrophysics

@article{Narayan2005BlackHI,
  title={Black holes in astrophysics},
  author={Ramesh Narayan},
  journal={New Journal of Physics},
  year={2005},
  volume={7},
  pages={199 - 199}
}
  • R. Narayan
  • Published 14 June 2005
  • Physics
  • New Journal of Physics
This paper reviews the current status of black hole (BH) astrophysics, focusing on topics of interest to a physics audience. Astronomers have discovered dozens of compact objects with masses greater than 3M⊙, the likely maximum mass of a neutron star. These objects are identified as BH candidates. Some of the candidates have masses ∼5M⊙–20M⊙ and are found in x-ray binaries, while the rest have masses ∼106M⊙–109.5M⊙ and are found in galactic nuclei. A variety of methods are being tried to… 

Figures from this paper

Super-spinning compact objects generated by thick accretion disks

If astrophysical black hole candidates are the Kerr black holes predicted by General Relativity, the value of their spin parameter must be subject to the theoretical bound |a*| ⩽ 1. In this work, we

Super-spinning compact objects generated by thick accretion disks

If astrophysical black hole candidates are the Kerr black holes predicted by General Relativity, the value of their spin parameter must be subject to the theoretical bound |a*| ≤ 1. In this work, we

Black Hole Superradiance in Astrophysics

BHs are one of the most striking predictions of Einstein’s GR and, in fact, they are predicted by any relativistic theory of gravity [1]. Since Schmidt’s identification of the first quasar [2], large

Towards the use of the most massive black hole candidates in AGN to test the Kerr paradigm

(could suggest they are very rapidly-rotating black holes. The moderate luminosity could indicate that their accretion disk is geometrically thin. If so, these objects could be excellent candidates

Kα iron line profile from accretion disks around regular and singular exotic compact objects

The nature of the super-massive black hole candidates in galactic nuclei can be tested by analyzing the profile of the K$\alpha$ iron line observed in their X-ray spectrum. In this paper, we consider

Testing the Kerr-nature of stellar-mass black hole candidates by combining the continuum-fitting method and the power estimate of transient ballistic jets

Astrophysical black hole candidates are thought to be the Kerr black holes predicted by General Relativity, as these objects cannot be explained otherwise without introducing new physics. However,

Testing the Nature of Astrophysical Black Hole Candidates

It is thought that the final product of the gravitational collapse is a Kerr black hole and astronomers have discovered several good astrophysical candidates. For the time being, all the black hole

A CODE TO COMPUTE THE EMISSION OF THIN ACCRETION DISKS IN NON-KERR SPACETIMES AND TEST THE NATURE OF BLACK HOLE CANDIDATES

Astrophysical black hole (BH) candidates are thought to be the Kerr BHs predicted by general relativity, but the actual nature of these objects has still to be proven. The analysis of the

Apparent shape of super-spinning black holes

We consider the possibility that astrophysical black holes (BHs) can violate the Kerr bound; i.e., they can have angular momentum greater than BH mass, J>M. We discuss implications on the BH apparent
...

References

SHOWING 1-10 OF 101 REFERENCES

Evidence for the Black Hole Event Horizon

Astronomers have discovered many candidate black holes in X-ray binaries and in the nuclei of galaxies. The candidate objects are too massive to be neutron stars, and for this reason they are

Intermediate - mass black holes

The mathematical simplicity of black holes, combined with their links to some of the most energetic events in the universe, means that black holes are key objects for fundamental physics and

Dynamical Constraints on Alternatives to Supermassive Black Holes in Galactic Nuclei

The compelling dynamical evidence for massive dark objects in galactic nuclei does not uniquely imply massive black holes (BHs). To argue convincingly that these objects are BHs we must rule out

Sources of Relativistic Jets in the Galaxy

▪ Abstract Black holes of stellar mass and neutron stars in binary systems are first detected as hard X-ray sources using high-energy space telescopes. Relativistic jets in some of these compact

Evidence for a black hole from high rotation velocities in a sub-parsec region of NGC4258

MANY galaxies are thought to contain massive black holes— exceeding ten million solar masses—at their centres1,2, but firm observational evidence has proved to be surprisingly elusive. The best

Black Hole Spin in X-Ray Binaries: Observational Consequences

We discuss the observational consequences of black hole spin in X-ray binaries within the framework of the standard thin accretion disk model. When compared with theoretical flux distribution from

Constraining Alternate Models of Black Holes: Type I X-Ray Bursts on Accreting Fermion-Fermion and Boson-Fermion Stars

The existence of black holes remains open to doubt until other conceivable options are excluded. With this motivation, we consider a model of a compact star in which most of the mass consists of dark

Black Hole and Neutron Star Transients in Quiescence

We consider the X-ray luminosity difference between neutron star and black hole soft X-ray transients (NS and BH SXTs) in quiescence. The current observational data suggest that BH SXTs are

On the Lack of Type I X-Ray Bursts in Black Hole X-Ray Binaries: Evidence for the Event Horizon?

Type I X-ray bursts are very common in neutron star X-ray binaries, but no type I burst has been seen in the dozen or so binaries in which the accreting compact star is too massive to be a neutron
...