Speaker
Description
LISA (Laser Interferometer Space Antenna) a planned space-based gravitational wave observatory to be launched in 2034 will be capable of detecting gravitational waves in the milli-Hertz band. Among various sources, LISA will detect the coalescence of massive black hole binaries (MBHBs) with total mass in range $[10^4-10^8] \mathrm{M_\odot}$ up to redshift $\sim$ 10. As such cataclysmic coalescence will take place in gas rich environments, they will be accompanied by electromagnetic (EM) radiation that can be triggered during the inspiral, merger and post-merger phase of the binary evolution. The joint observation of gravitational waves and associated EM counterpart will lead to unveil the astrophysical environment around merging binaries and constrain the cosmological parameters. As these sources will be observed at a very high redshift, the associated EM counterpart will be characterized by faint EM emission. Therefore, in order to promptly locate them in the sky using EM facilities, accurate sky localization using gravitational wave observation is crucial well ahead of merger. Although the GW signal from such sources lasts for several months (or days) in the detector's bandwidth, the signal-to-noise ratio surpass the detection threshold only few days (or hours) before merger, challenging the accurate inference of source parameters including sky localization. We extend the recently developed Bayesian inference pipeline assisted by meshfree approximation of the likelihood function for MBHBs to be seen in LISA and estimate source parameters as a function of time left before coalescence.
| sharma.abhishek@iitgn.ac.in | |
| Affiliation | Indian Institute of Technology Gandhinagar |
