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This will sound cynical, but at this point, it's no longer news unless it's a binary neutron star merger. If there's an electromagnetic counterpart, then it's b
by DiogenesKynikos 7y ago
This will sound cynical, but at this point, it's no longer news unless it's a binary neutron star merger. If there's an electromagnetic counterpart, then it's big news.
If you have a gravitational wave detection with an EM counterpart, you can get a redshift and luminosity distance, which means that you can measure the Hubble constant (in a way that is completely independent from Type Ia Supernovae). Binary black hole mergers are not expected to give off any EM radiation.
There should be a few binary neutron star mergers this run, and with some luck, there may be one with an EM counterpart.
- cperciva 7y agoPresumably if the location could be determined accurately enough and it was close to a galaxy, we could conclude that it was most likely in that galaxy, and thereby get a useful measurement though?
- DiogenesKynikos 7y agoNot with gravitational waves alone. People do want to correlate large numbers of binary black hole mergers with galaxy positions and come up with a statistical measurement of the Hubble constant, but no single BBH merger will be clearly identified with one galaxy under that scheme. You need lots of mergers, and the Hubble-constant determination is more model-dependent. Binary neutron stars with EM counterparts are much more straightforward.
- pfdietz 7y agoI'm waiting for a neutron star + black hole merger.