PGI Virtual Seminar Series | Elias Most "Neutron star mergers: On the impact of high spins in multi-messenger gravitational wave events"

Mon, Sep 28, 2020, 12:30 pm
Location: 
via Zoom
Abstract:
Since the first detection of a gravitational wave event of the merger of two neutron stars in 2017, two more detections in the neutron star mass range have been announced earlier this year. The first one, GW190425, involved an unusually massive neutron star, the second one, GW190814, had a companion in the lower mass gap that could either have been the heaviest neutron star or the lightest black hole ever observed. One of the uncertainties in those detections is allowing for the possibility of having high initial spins before the merger.  
In this talk, I will discuss the potential observational impact of the presence of high spins in the inspiral. In particular, I will show what effect high spins can have on the emission of – yet to be observed – electromagnetic precursors and on the mass ejected dynamically during the merger process.
This will be followed by the presentation of a new method to place limits on high spins and small mass ratios in mergers involving a very massive neutron star, such as GW190425.

Finally, I will comment on potential implications for the equation of state, in case the secondary in GW190814 was (once) a neutron star. Following up on the possibility of having low mass black holes in the lower mass gap, I will present the results of an on-going study of near equal mass black hole-neutron star mergers. In particular, I will focus on the impact of initial black hole spin on the viability for electromagnetic counterparts.

Email Angela Lewis for Zoom registration.