X-ray Flares from Postmerger Millisecond Pulsars
Z. G. Dai,1*
X. Y. Wang,1
X. F. Wu,2
B. Zhang3
Recent observations support the suggestion that short-duration
gamma-ray bursts are produced by compact star mergers. The x-ray
flares discovered in two short gamma-ray bursts last much longer
than the previously proposed postmerger energy-release time
scales. Here, we show that they can be produced by differentially
rotating, millisecond pulsars after the mergers of binary neutron
stars. The differential rotation leads to windup of interior
poloidal magnetic fields and the resulting toroidal fields are
strong enough to float up and break through the stellar surface.
Magnetic reconnection–driven explosive events then occur,
leading to multiple x-ray flares minutes after the original
gamma-ray burst.
2 Purple Mountain Observatory and Joint Center for Particle Nuclear Physics and Cosmology of Purple Mountain Observatory–Nanjing University, Chinese Academy of Sciences, Nanjing 210008, China.
3 Department of Physics, University of Nevada, Las Vegas, NV 89154, USA.
* To whom correspondence should be addressed. E-mail: dzg{at}nju.edu.cn
