New answers tagged black-hole
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The "mass gap" is an observed deficit in the number of compact objects with mass between 2.5 and 5 solar masses.
The "mass gap" is/was not understood. Such objects may be rare because they are difficult to detect or because something about the supernova process leads to a bifurcation between the most massive neutron stars and the least ...
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The duration of a gravitational wave detection is not particularly important in detecting electromagnetic counterparts, although the fact that they are not recurrent or repeating sources is.
Binary systems continually emit gravitational waves, up until the time that they merge, predominantly at twice the orbital frequency. At the same time, the power emitted ...
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Just a supplement to @JamesK's excellent answer. The image below (from Caltech/MIT by way of New Sciencist) shows what was detected for one collision. On the left (at the start) the blackholes orbit one another about every 0.03 seconds, but the waveform is too faint to detect. At about 0.3 seconds on the Time axis the waves start being detectable and the ...
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We can currently only detect gravitational radiation when it is extremely intense: in the last fraction of a second. For example the first gravitational wave detection lasted less 0.15 seconds. The black holes are releasing gravitational radiation with every orbit, but that radiation is too weak for us to detect. It takes a colossal amount of energy being ...
2
According to an article in the NewScientist, there is a natural size limit:
When black holes at the hearts of galaxies swell to 50 billion times the mass of our sun, they may lose the discs of gas they use as cosmic feedlots.
Most galaxies host a supermassive black hole at their centre. Around this is a region of space where gas settles into an orbiting ...
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Not enough to worry about.
Most neutrinos we detect on Earth come from the sun. The black hole at the centre of the galaxy is not so close to a star as the Earth is so you would expect the neutrino flux to be lower than on Earth, let's assume it is similar: about 10¹¹ neutrinos per cm² per second. But each neutrino is light, even including its kinetic ...
7
You are essentially asking the following: if someone falls from the Earth from some way beyond the event horizon of a black hole, how long after they have left can an observer on Earth still signal to them with a light beam?
The answer of course depends on exactly how far the Earth is from the black hole. It is also often forgotten that it is not just light ...
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