High Energy Astrophysics and Gravitational Wave Sources: New Results from Magnetars and Short Gamma Ray Bursts
INAF - Osservatorio Astronomico di Roma
ABSTRACT: Over the last decade considerable evidence has been found
for the existence of magnetars, neutron stars whose
electromagnetic emission is powered by the decay of their
extremely high magnetic field. A new perspective in this
field was brought about by the 2004 December 27 giant flare from
the magnetar in the soft gamma-ray source SGR 1806-20.
The enormous energy liberated in this event points to an
internal magnetic field strength of >1016 Gauss.
For such a field the gravitational wave signal in the
first few days after formation of a fast spinning magnetar
is expected to be so strong that it can be detected with
Advanced LIGO/Virgo class interferometers up to the distance
of the Virgo cluster, where ~1 magnetar per year is born.
There is now (indirect) evidence that short Gamma
Ray Bursts originate in the merging of binary systems
containing two neutron stars, or a neutron star and a black
hole. Coalescing binaries are considered among the most
promising GW sources. Recent results on short Gamma Ray
Bursts indicate that a sizeable fraction of these events take
place at low redshift and in globular clusters of stars,
where they can be more easily detected by gravitational wave