Séminaire Univers / |
| « Nanohertz gravitational wave astrophysics with pulsar timing arrays » |
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Chiara M. F. Mingarelli |
| Galaxy mergers are a standard aspect of galaxy formation and evolution, and likely all large galaxies contain central supermassive black holes (SMBH). Here I give an overview of recent developments in nanohertz gravitational-wave (GW) astrophysics, and discuss how the final parsec problem can directly affect the shape of the GW background strain spectrum. I also discuss my new bottom-up approach to identifying SMBH binary host galaxies by using massive ellipticals in 2MASS, assessing the likelihood of detecting one of these sources with Pulsar Timing Arrays (PTAs), their contribution to the GW background and its anisotropy, and report on the characteristics of the most detected SMBH binaries and host galaxies. We find that out to 225 Mpc there are on average 91 sources emitting GWs in the PTA band and 7 stalled binaries. The chance of detecting these GW sources with current PTA data is <1%, however in the next 10 years PTAs probe a region of the parameter space rich in sources, making a 3-sigma (or better) detection very likely. |
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mardi 22 mai 2018 - 11:15 Salle 281 Institut d'Astrophysique de Paris |
| Pages web du séminaire / Seminar's webpage |