Observational Signatures of Coalescing Neutron Star Binaries

Brian Metzger (Columbia) - September 8, 2014 at 12:10 pm

The merger of binary neutron stars (NSs) are the most promising sources for the direction detection of gravitational waves with Advanced LIGO and Virgo starting in the next few years. Maximizing the scientific potential of these discoveries will require identifying a coincident electromagnetic counterpart. Among the most promising counterparts is a day-week long supernova-like transient (a `kilonova') powered by the radioactive decay of nuclei synthesized in the merger ejecta. I will discuss recent updates in our understanding on kilonovae, including the diversity in their light curves and colors introduced by considering outflows from the remnant accretion disk and the influence of a long-lived hyper-massive NS. I will also describe a new component of bright optical/UV emission, peaking on timescales of just ~hours after the merger, powered by the beta-decay of free neutrons residing in the outermost layers of the ejecta. This neutron-powered `precursor' to the main kilonova could encode valuable information on the properties of the binary (e.g. NS-NS vs. NS-BH) and the NS equation of state. I will conclude by describing the implications of stable NS merger remnants for upcoming radio transient surveys.

The seminar will be held in 131A Campbell Hall.

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