Description:

Om Sharan Salafia, University of Milano-Bicocca

Host: Wen-fai Fong

Where and When: How to Combine Information from the GW Signal and EM Counterpart Models to Inform and Optimize the EM Follow-up Strategy

The electromagnetic follow-up of a gravitational wave event requires astronomers to scan a wide sky region for the detection and identification of a transient whose features are very uncertain a priori. A sky position posterior probability map (“skymap”) is provided by the LIGO/Virgo collaboration (containing information on "where" to search), but no timing ("when") information is available, other than conjectures based on the expected properties of the candidate EM counterparts. I will describe a novel approach to schedule observations using information from GW parameter estimation, thus allowing for an event-specific optimization of the EM follow-up strategy. I will illustrate the result of applying the approach to an example NS-NS injection with an associated SGRB oprhan afterglow and dynamical ejecta macronova, showing that the follow-up is significantly improved. I will discuss the possible application of the method to future real GW triggers, including the case when only low-latency information is available.