Highly magnetic neutron stars: bewildering astrophysical laboratories and cosmological tools
Rosalba Perna
University of Colorado at Boulder
Anomalous X-ray Pulsars and Soft Gamma-Ray Repeaters (SGRs) are young
neutron stars characterized by high X-ray quiescent luminosities,
outbursts, and, in the case of SGRs, sporadic giant flares. They are
believed to be magnetars, that is neutron stars powered by ultra-strong
magnetic fields. However, the diversity of their behaviours, and,
especially, the observation of magnetar-like bursts from `low-field'
neutron stars, has been a theoretical puzzle. In the first part of
the talk, I will discuss results of long-term MHD simulations which,
by following the evolution of magnetic stresses within the neutron star
crust, have allowed to relate the observed magnetar phenomenology to the
physical properties of the neutron stars, and in particular to their age
and magnetic field strength and topology. The dichotomy of `high-B' field
pulsars versus magnetars is naturally explained, and occasional outbursts
from old, low B-field neutron stars are predicted. In the second part of
the talk, I will discuss how observations of highly magnetized neutron
stars can be handy tools in the cosmological domain, and in particular
as a way to set constraints on the hypothetical particle `axion'.
Date: | Tuesday, 3 April 2012 |
Time: | 16:00 |
Where: | McGill University |
| Ernest Rutherford Physics Building, R.E. Bell Conference Room (room 103) |
Contact: | Robert Rutledge |
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