All Questions
Tagged with black-holes binary-stars
34
questions
6
votes
1
answer
87
views
Extreme Mass Ratio Inspirals and GWs cycles
I was reading through the following paper GRMHD study of accreting massive black hole binaries in astrophysical environment: A review. Therein, we have the following image
It is not quite clear how ...
- 1,213
4
votes
1
answer
87
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Do we use transit photometry to look for a black hole star binary systems?
What would a light curve look like for a black hole transiting a star? Initially I thought it would bend all light essentially blacking out a star but we would probably still detect some however the ...
- 1,348
4
votes
0
answers
83
views
Hills Mechanism
The Hills mechanism postulates that when a stellar binary system is perturbed by a supermassive black hole (SMBH), the tidal forces at play result in the capture of one star while simultaneously ...
- 1,213
1
vote
1
answer
46
views
Closest possible orbital radius for equal masses
If you have two objects of equal mass, then what’s the closest distance that they can orbit at in terms of their schwarzschild radii? How fast would they be orbiting?
What About stable orbits?
- 2,888
1
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1
answer
47
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If two black holes orbit around each other should their tidal forces cause a shrinking of the closer parts of their event horizons?
I recently asked a question about the influence of external gravitational fields on the stability of the geometry of a part or all the event horizon of a black hole. I understood the answer in a ...
- 2,245
0
votes
1
answer
37
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Invariance of binary black hole gravitational waves
Why BBH gravitational waves can be parameterized with the mass ratio? (and is not necessary the value of the two masses explicitly)
- 1
0
votes
1
answer
66
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Does SXS catalog for NR simulations have non-spinning, non-eccentric blackholes?
I am looking for NR waveform for two non-spinning and non-eccentric black hole binary merger for small mass ratio. Somehow, on the SXS catalog website, I don't see any such description.
Thanks
- 125
2
votes
1
answer
40
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Should a black holes binary system in fase of imminent merge shrink the parts of the event horizons of both black holes where they face each other?
Should a black holes binary system in fase of imminent merge shrink the inner parts of the event horizons of both black holes where they directly face each other? So the 'singularities' have the inner ...
- 2,245
0
votes
1
answer
72
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How to convert from polarization modes ($h_{+}$, $h_{×}$) to obtain spin-weighted spherical harmonic $h_{lm}$ as a function of $h_{+}$, $h_{×}$?
This question arises from a discussion in the thread How to convert from plus and cross polarization modes ($h_{+}$, $h_{×}$) to spin-weighted spherical harmonic $h_{lm}$?
I was looking for a ...
- 125
16
votes
3
answers
2k
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Time dilation effects at the center of a binary black hole system
Imagine two identical black holes in a circular orbit, and Alice is smack-dab in the middle of the system (at the barycenter). Bob is at infinity.
Let's assume that Alice and Bob are stationary ...
- 769
5
votes
2
answers
703
views
Can two relativistic black holes' event horizons overlap and separate again?
I have read this question:
What I have not seen is a purely classical argument for the non-separation of a black hole merger. One can obviously take the time reversed spacetime manifold of a merger ...
- 29k
0
votes
1
answer
79
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Gauge independence of the gravitational-wave frequency and gauge dependence of the binary separation?
In the seminal paper by Cutler & Flanagan (1994), which uses multi-timescale analysis to derive waveforms in the post-Newtonian approximation without spin effects, they state that,
"In Eq. (...
- 2,749
5
votes
2
answers
219
views
Black holes: Is merger inevitable when horizons touch?
I watched a simulation of the binary black hole merger of 2019 April 12
https://www.ligo.caltech.edu/video/ligo20200420v1
When the "apparent horizons" (their terminology; are those ...
- 265
5
votes
1
answer
422
views
Is there an approximate expression for the force between two black holes?
Just curious: is there an approximate expression for the gravitational attraction between two Schwarzschild black holes of masses $M$ and $m$, held without relative speed at some center to center ...
user85598
-2
votes
1
answer
90
views
An apparent paradox in General relativity using a binary black hole
Note: Quantum gravity effects are ignored in this question.
Imagine 2 black holes each with mass $m$ approaching each other and after some time the Event Horizons (EHs) of both black holes touch each ...
- 1,570