Yun-Wei Yu, Bing Zhang, He Gao
A massive millisecond magnetar may survive a merger of a neutron star (NS) binary, which could continuously power the merger ejecta and accelerate it to a mildly-relativistic speed. We develop a generic dynamic model for the merger ejecta, where the transition from sub-relativistic to relativistic is well described. We show that the ejecta emission (the "merger-nova") powered by the magnetar can have an optical peak brightness comparable to a supernova, which is a few tens or hundreds times brighter than the radioactive-powered merger-novae (the so-called macro-nova or kilo-nova). However, the duration of the magnetar-powered merger-nova peaks earlier and has a duration significantly shorter than that of a supernova. An X-ray bump appears even earlier in time. Such merger-novae may be detected with NS-NS merger events with or without a short gamma-ray burst, and could be a bright electromagnetic counterpart for gravitational wave bursts due to NS-NS mergers. If detected, it suggests that the merger leaves behind a massive NS, which has important implications in understanding the equation-of-state of nuclear matter.
View original:
http://arxiv.org/abs/1308.0876
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