Tidal-heating and viscous dissipation correspondence in black holes and viscous compact objects

We have solved the General Relativistic Hydrodynamic (GRH) equations using the high resolution shock capturing scheme (HRSCS) to find out the dependency of the disk dynamics to the Mach number, adiabatic index, the black hole rotation parameter and the outer boundary of the computational domain around the non-rotating and rotating black holes. We inject the gas to computational domain at upstream and downstream regions at the same time with different initial conditions. It is found that variety of the mass accretion rates and shock cone structures strongly depend on Mach number and adiabatic index of the gas. The shock cones on the accretion disk are important physical mechanisms to trap existing oscillation modes, thereupon these trapped modes may generate strong X-rays observed by different X-ray satellites. Besides, our numerical approach also show that the shock cones produces the flip–flop oscillation around the black holes. The flip–flop instabilities which are monitored in our simulations may explain the erratic spin behavior of the compact objects (the black holes and neutron stars) seen from observed data.

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THE UNIFICATION OF RELATIVISTIC JETS

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194514601884 ◽

2014 ◽

Vol 28 ◽

pp. 1460188 ◽

Cited By ~ 11

Author(s):

LUIGI FOSCHINI

Keyword(s):

Black Holes ◽

Neutron Stars ◽

Mass Range ◽

Supermassive Black Holes ◽

Compact Objects ◽

Relativistic Jets

I report about the unification of relativistic jets from compact objects. The mass range is between 1.4 and 10 billion solar masses (i.e. from neutron stars to supermassive black holes in galaxies).

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Cosmological black holes are not described by the Thakurta metric: LIGO-Virgo bounds on PBHs remain unchanged

The European Physical Journal C ◽

10.1140/epjc/s10052-021-09803-4 ◽

2021 ◽

Vol 81 (11) ◽

Author(s):

Gert Hütsi ◽

Tomi Koivisto ◽

Martti Raidal ◽

Ville Vaskonen ◽

Hardi Veermäe

Keyword(s):

Black Holes ◽

Black Hole ◽

Dark Matter ◽

Compact Object ◽

Compact Objects ◽

Primordial Black Hole ◽

Mass Growth ◽

Black Hole Binaries ◽

Physical Conditions ◽

Accretion Physics

AbstractWe show that the physical conditions which induce the Thakurta metric, recently studied by Bœhm et al. in the context of time-dependent black hole masses, correspond to a single accreting compact object in the entire Universe filled with isotropic non-interacting dust. In such a case, accretion physics is not local but tied to the properties of the whole Universe. We show that radiation, primordial black holes or particle dark matter cannot produce the specific energy flux required for supporting the mass growth of the compact objects described by the Thakurta metric. In particular, this solution does not apply to black hole binaries. We conclude that compact dark matter candidates and their mass growth cannot be described by the Thakurta metric, and thus existing constraints on the primordial black hole abundance from the LIGO-Virgo and the CMB measurements remain valid.

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The stellar graveyard

Gravitational-Wave Astronomy ◽

10.1093/oso/9780198568032.003.0009 ◽

2019 ◽

pp. 177-206

Author(s):

Nils Andersson

Keyword(s):

Black Holes ◽

General Relativity ◽

Neutron Stars ◽

Gravitational Wave ◽

Stellar Evolution ◽

White Dwarfs ◽

Supermassive Black Holes ◽

Compact Objects ◽

Fermi Gases ◽

The 1950S

This chapter introduces the different classes of compact objects—white dwarfs, neutron stars, and black holes—that are relevant for gravitational-wave astronomy. The ideas are placed in the context of developing an understanding of the likely endpoint(s) of stellar evolution. Key ideas like Fermi gases and the Chandrasekhar mass are discussed, as is the emergence of general relativity as a cornerstone of astrophysics in the 1950s. Issues associated with different formation channels for, in particular, black holes are considered. The chapter ends with a discussion of the supermassive black holes that are found at the centre of galaxies.

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Accretion onto Relativistic Objects

Symposium - International Astronomical Union ◽

10.1017/s0074180900236346 ◽

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.

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Effect of Compact Objects Near Be Stars

International Astronomical Union Colloquium ◽

10.1017/s0252921100116720 ◽

1987 ◽

Vol 92 ◽

pp. 516-518

Author(s):

Krishna M.V. Apparao ◽

S.P. Tarafdar

Keyword(s):

Black Holes ◽

Neutron Star ◽

Rotation Period ◽

Compact Object ◽

Compact Objects ◽

X Rays ◽

Be Stars ◽

Eccentric Orbit ◽

X Ray ◽

Be Star

Several Be stars are identified with bright X-ray sources. (Rappaport and Van den Heuvel, 1982). The bright X-ray emission and observed periodicities indicate the existence of compact objects (white dwarfs, neutron stars or black holes) near the Be stars. A prime example is the brightest X-ray source A0538-66 in LMC, which contains a neutron star with a rotation period of 59 ms. Apparao (1985) explained the X-ray emission, which occurs in periodic flares, by considering an inclined eccentric orbit for the neutron star around the assumed Be-star. The neutron star when it enters a gas ring (around the Be-star) accreting matter giving out X-rays.The X-ray emission from the compact objects, when the gas ring from the Be-star envelopes the objects, has interesting consequences. The X-ray emission produces an ionized region (compact object Stromgren sphere or COSS) in the gas surrounding the compact object (CO).

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