Well, as it was informed in the press conference of GW discovery, the event had occurred 1.3 billion years ago; that is when life on earth has just begun multi-cellular! As evident, universe was smaller in the past than it is now, the merging of two massive gravitational bodies would have been more favorable.
To Thierry De Mees : do you mean that any and all massive stars are expected to form binaries, according to your work (which I did not have time look yet, sorry!).
But I know that the community, in this specific GW case, is very astounded : it is quite surprising statistically that the first GW detection comes from a binary system with two massive (30 Msun each) BHs, so that people start to entertain the idea that the 2 BHs indeed originate from a single core collapse, the core splitting somehow. This recoups what Thierry is alluding to, but it is the specific case of a binary with 2 massive BH that requires such original considerations, compared to the more standard binary formation scenarios. I do not think that the compactness argument holds 1,3 billion years ago (id est what Vikash writes is formally true, but I believe bears no significant impact on the statistics of binaries)
Johann, Thierry is not talking about current theory, he is using an incomplete theory that was a precursor to GR. The "apparent mass increase" is his own invention based on that theory.
From your link:
".. an approximation, valid under certain conditions, to the Einstein field equations for general relativity."
"The analogy and equations differing only by some small factors were first published in 1893, before general relativity, by Oliver Heaviside as a separate theory"
Those seem to be consistent with what I said. You did tell me you were using Heaviside's theory rather than the same name used to describe the weak field approximation of GR a few weeks or months ago.
Carlos, have you seen the attached paper, it gives an overview of possibilities.
http://iopscience.iop.org/article/10.3847/2041-8205/818/2/L22/pdf
A few things are being overlooked. It may be unfashionable to mention this but it was apparent to Einstein and Dirac that since gravitational time dilation prohibits the ingress of matter into a black hole, the stationary black holes cannot be a realistic outcome of gravitational collapse. It is therefore unlikely that any black hole candidate truly possesses an event horizon. This is consistent with the latest gravitational wave data if you care to take a second look at it (see below).
The lack of genuine event horizons (which shows the BH information paradox to be naive) allows radical departures from the Kerr geometry in some cases. Indeed, quasars have the hallmarks one would expect of electrically charged toroidal quasi-black holes: relativistic jets, extreme energies and finite lifespans - even in galaxy clusters which have no shortage of gas to feed accretion disks (see below).
Where galactic gas reserves are plentiful, extremely massive stars are likely to form - often with high angular momentum. Short-lived, these stars could retain a great deal of their original angular momentum at the time of their collapse - potentially forming toroidal (quasi) black holes. There is no obvious limit to their mass since their major radius can in principle be much larger than their minor radius. In time, the tori collapse to form something resembling a Kerr BH (still lacking an event horizon). These objects will be far more common than supermassive "black holes" and will tend to congregate near the cores of galaxies, boosting their local concentration.
As they coalesce, gravitational waves are produced within the frequency range to which LIGO was particularly sensitive. I think for these reasons, it was not so surprising that gravitational waves were first detected from very distant dark holes having these unexpectedly large massess.
Article Quasars: A supermassive rotating toroidal black hole interpretation
Preprint Dispelling Black Hole Pathologies Through Theory and Observation
Preprint Coincident Down-chirps in GW150914 Betray the Absence of Eve...
Observatory (LIGO), the researchers detected ripples in the fabric of space-time called gravitational waves. But on that same day — less than half a second after LIGO made its monumental discovery — the Fermi Telescope, a space observatory orbiting the earth, picked up a brief, faint signal from the same region of space. The chances of that being coincidental hover around 0.2%. And if it wasn't a coincidence, it could open the door to a whole new world of physics. According to what we know about black holes, this shouldn't have happened: Light shouldn't be able to escape from two betrothed black holes since any gas surrounding them would be swallowed up by one before it merged. . But there's a problem with the gravitational-wave observatories we have now: They possess relatively blurry vision, according to NASA.. Black holes does no longer exist, they are just accretion discs.
https://www.researchgate.net/deref/http%3A%2F%2Fsvs.gsfc.nasa.gov%2Fcgi-bin%2Fdetails.cgi%3Faid%3D12216
Chapter Nonsingular Black Holes
@Carlos
The GW was very brief (seconds), this implies that there was a progenitor star that because of it s rapid rotation, first collapsed into two black holes and then the two black holes rapidly merged.
I agree with @ Robin that down chirps should not occurr and equally there should have been no flash, a modification to GTR would be necessary to fully explain this.
If you require further information on a modification of GTR, i would be happy to supply.
Andrew, the detection was brief because the frequency only rose into the detection range of LIGO in the last few cycles. The signal would have been there continuously for millions of years before that. If eLISA is ever launched, it would have the ability to detect signals at lower frequencies and give us an early warning of events that could later be detected by LIGO.
@ Dissman
Just to be clear yours is not the conventional view
But the conventional view needs some explanation for various problems which Thierry and Robin espouse
Just to be clear, mine is the conventional view.
There has been no publication of any observed difference between the detection and theory, and theory says that the signal should have been continuous for a very long time.
You can look at the Hulse and Taylor system which should merge in about 300 million years and consider the recent LIGO detection as similar to the end-point of that process.
http://www.astro.cornell.edu/academics/courses/astro201/psr1913.htm
Thank you Andrew. Just to be clear, I am very much an amateur student of cosmology so if anything I say seems unconventional, it is almost certainly an error on my part or perhaps an ambiguous statement of the conventional view.
This has not answered the original question has it? How have these black holes originated? My understanding is that because of the low spin of the progenitor black holes it is most likely that these black holes are the remnants of exceedingly large population 3 stars in the very early universe. These stars likely formed as a binary. However this is by no means clear cut from the data. Hopefully we will have more gravitational wave detections in the near future to make a clearer picture of where this population of black holes have come from.
The paper I cited earlier contains the best interpretation from the LIGO team and has a number of references to other papers which discuss the present best current understanding of various formation scenarios. I'll repeat it here for ease of access. Note the original link seems to be unreliable but this is the same paper.
https://dcc.ligo.org/public/0122/P1500262/015/apjl_818_2_L22.pdf
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