Speaker
Dr
Maria Grazia Bernardini
(INAF - Osservatorio Astronomico di Brera)
Description
Newly-born millisecond magnetars are competing with black holes as source of the gamma-ray burst (GRB) power, mainly with their rotational energy reservoir. They may be formed both in the core-collapse of massive stars, and in the merger of neutron star or white dwarf binaries, or in the accretion-induced collapse of a white dwarf, being thus a plausible progenitor for long and short GRBs, respectively. In ten years of activity, Swift has provided compelling observational evidences supporting the magnetar central engine, as the presence of a plateau phase in the X-ray light curve, the extended emission in SGRBs and the precursor and flaring activity. We review the major observational evidences for the possible presence of a newly-born magnetar as the central engine for both long and short GRBs. We then discuss about the possibility that all GRBs are powered by magnetars, and we propose a unification scheme that accommodates both magnetars and black holes, connected to the different properties and energetics of GRBs.
Primary author
Dr
Maria Grazia Bernardini
(INAF - Osservatorio Astronomico di Brera)