Séminaires généraux
Black holes in LISA, VIRGO and not only
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US/Central
Amphi Pierre Lehmann (LAL)
Amphi Pierre Lehmann
LAL
Description
One of the most relevant goals for LISA is the detection of the capture of stars by supermassive black holes (SMBH). This source, non visible by ground detectors, attracts the interest of astrophysicists, physicists and data analysts. An international effort is therefore taking place on several issues concerning the population of SMBH in the universe, the distribution and typology of stars around SMBH, tests on general relativity and alternative theories, the measurement of mass and spin of SBMH. Only few tens of captures are foreseen being individually visible for LISA. Instead, most of the sources, some hundreds, will contribute to the noise floor of LISA. The waveforms depend on 17 parameters and given the yearly or longer observation time, a huge number of templates is associated if matched filtering would be adopted; therefore or reduction of parameters, hierarchical searches or robust time and frequency methods ought to be envisaged. Such robust methods could be envisaged for VIRGO for the coalescences of black holes and ground based detectors may observe captures indirectly, in the high frequency regime.
Radiation reaction strongly affects the waveform phase, and its computation must be performed to not miss detection. We mention the relation between the geodetic and pragmatic approaches, radiation reaction and equivalence principle.
Finally, we underline the synergy that gravitational wave research might have with the observation of massive black holes in the electromagnetic spectrum (HAR, Planck, Herschel, James Webb).