scholarly journals Some Aspects of Binary Compact Astrophysical Objects

2008 ◽  
Vol 7 (1) ◽  
pp. 64-70
Author(s):  
Kenath Arun

This paper shall look into the systems of compact astrophysical objects (black holes, neutron stars and white dwarfs) concerning mainly with binary systems. Determination of the orbital periods, velocities, etc, for such systems and also, the energy lost from the system through gravitational waves has been made, From the concept of energy loss, the merger of the two black holes in the system has been considered and the typical time required for the merger is calculated.

2000 ◽  
Vol 177 ◽  
pp. 579-584
Author(s):  
V. Kalogera

AbstractThe coalescence of close binary systems with two compact objects (neutron stars and black holes) are considered to be promising sources of gravitational waves for the currently built laser interferometers. Here, I review the current Galactic coalescence estimates derived both theoretically and empirically. I discuss the uncertainties involved as well as ways of obtaining an upper limit to the coalescence rate of two neutron stars.


Author(s):  
Rabinarayan Swain ◽  
Priyasmita Panda ◽  
Hena Priti Lima ◽  
Bijayalaxmi Kuanar ◽  
Biswajit Dalai

Detection of Gravitational waves opened a new path for cosmological study in a new approach. From the detection of gravitational waves signal by advanced LIGO, its research climbed the peak. After the collaboration of LIGO and Virgo, several observations get collected from different sources of binary systems like black holes, binary neutron stars even both binary black hole and neutron star. The rigorous detection of gravitational signals may provide an additional thrust in the study of complex binary systems, dark matter, dark energy, Hubble constant, etc. In this review paper, we went through multiple research manuscripts to analyze gravitational wave signals. Here we have reviewed the history and current situation of gravitational waves detection, and we explained the concept and process of detection. Also, we go through different parts of a detector and their working. Then multiple gravitational wave signals are focused, originated from various sources and then found correlation between them. From this, the contribution of gravitational waves in different fields like complex binary systems (black holes, neutron stars), dark matter, dark energy and Hubble Constant have been discussed in this manuscript.


1974 ◽  
Vol 64 ◽  
pp. 194-212
Author(s):  
M. J. Rees

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.


2018 ◽  
Vol 14 (S346) ◽  
pp. 1-13
Author(s):  
Edward P. J. van den Heuvel

AbstractA summary is given of the present state of our knowledge of High-Mass X-ray Binaries (HMXBs), their formation and expected future evolution. Among the HMXB-systems that contain neutron stars, only those that have orbital periods upwards of one year will survive the Common-Envelope (CE) evolution that follows the HMXB phase. These systems may produce close double neutron stars with eccentric orbits. The HMXBs that contain black holes do not necessarily evolve into a CE phase. Systems with relatively short orbital periods will evolve by stable Roche-lobe overflow to short-period Wolf-Rayet (WR) X-ray binaries containing a black hole. Two other ways for the formation of WR X-ray binaries with black holes are identified: CE-evolution of wide HMXBs and homogeneous evolution of very close systems. In all three cases, the final product of the WR X-ray binary will be a double black hole or a black hole neutron star binary.


2017 ◽  
Vol 95 (12) ◽  
Author(s):  
Paola Leaci ◽  
Pia Astone ◽  
Sabrina D’Antonio ◽  
Sergio Frasca ◽  
Cristiano Palomba ◽  
...  

2001 ◽  
Vol 10 (04) ◽  
pp. 381-441 ◽  
Author(s):  
NILS ANDERSSON ◽  
KOSTAS D. KOKKOTAS

In this review we summarize the current understanding of the gravitational-wave driven instability associated with the so-called r-modes in rotating neutron stars. We discuss the nature of the r-modes, the detailed mechanics of the instability and its potential astrophysical significance. In particular we discuss results regarding the spin-evolution of nascent neutron stars, the detectability of r-mode gravitational waves and mechanisms limiting the spin-rate of accreting neutron stars in binary systems.


Author(s):  
John W. Moffat

Civita criticized Einstein’s papers on gravitational waves: their energy momentum is frame dependent and therefore does not fit the covariance of Einstein’s gravity theory. Infeld and Rosen did not believe gravitational waves existed, and Einstein changed his mind on their existence repeatedly. Others did believe in them, such as Fock and Feynman. Weber constructed his “Weber bar” to detect gravitational waves, but when he claimed success, he was criticized. He then proposed using a Michelson-Morley type of interferometer with lasers to detect gravitational waves, as did Weiss. Merging black holes and neutron stars were proposed as detectable sources of gravitational waves. Taylor and Hulse, using the large Arecibo radio telescope, indirectly detected gravitational waves from inspiraling neutron stars. Primordial gravitational waves, still emanating from the Big Bang, were claimed to have been detected by BICEP2, but the waves were eventually shown to be a result of foreground dust.


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