New answers tagged gravitational-waves
4
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 ...
3
Unlikely.
The Neutron star merger GW170817 had an optical counterpart (SSS 17a) The optical magnitude peaked at about +18, this is beyond the abilities of most amateur set ups.
Black hole mergers may be intrinsically more energetic, but less bright in the electromagnetic spectrum, as the black holes don't have a surface to interact electromagnetically.
...
7
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 ...
7
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 ...
12
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 ...
6
Let me see if I can try answering both parts of your question. The key is a combination of two things: 1) Most of the binary BHs in an accretion disk will have their binary orbits in the same plane as the accretion disk, so that "perpendicular to the binary plane" = "perpendicular to the accretion disk"; 2) The most effective form of ...
4
I would think that the same reason that a gas disk enhances the growth of planetesimals. Drag from the disk enforces circular, co-planar orbits, which in turn means that objects that get close to each other have small relative velocities.
Edit: So what is thought to be going on is a little bit more complex than the simple answer above. The density of massive ...
2
Gravitational waves carry away the momentum
From wikipedia
Black-hole merger recoil
An unexpected result can occur with binary black holes that merge, in that the gravitational waves carry momentum and the merging black-hole pair accelerates seemingly violating Newton's third law. The center of gravity can add over 1000 km/s of kick velocity.[30] The ...
Top 50 recent answers are included
