1,136 research outputs found
Relativistic Gravity and Binary Radio Pulsars
Following a summary of the basic principles of pulsar timing, we present a
review of recent results from timing observations of relativistic binary
pulsars. In particular, we summarize the status of timing observations of the
much celebrated original binary pulsar PSR B1913+16, draw attention to the
recent confirmation of strong evidence for geodetic precession in this system,
review the recent measurement of multiple post-Keplerian binary parameters for
PSR B1534+12, and describe the Parkes Multibeam survey, a major survey of the
Galactic Plane which promises to discover new relativistic binary pulsar
systems.Comment: 12 pages, 3 EPS figures, proceedings of 8th Canadian Conference on
General Relativity and Relativistic Astrophysics, held June 1999, McGill
University, Montreal, Quebec, Canad
High Magnetic Field Rotation-powered Pulsars
Anomalous X-ray pulsars and soft gamma repeaters have recently emerged as a
unified class of neutron stars, identified by dramatic X-ray and gamma-ray
outbursts and via luminous X-ray pulsations, both thought to be powered by the
decay of an enormous internal magnetic field. This "magnetar" hypothesis has
raised the question of these objects' physical relationship with conventional
rotation-powered pulsars (RPPs). The highest magnetic-field RPPs might
therefore be expected to be transition objects between the two populations. The
recently reported magnetar-like outburst of PSR J1846-0258, previously thought
to be purely rotation-powered, clearly supports this suggestion. Here we review
the observational properties of the highest magnetic-field RPPs known, and show
some common characteristics that are notable among RPPs, which are plausibly
related to their high fields. Using these objects, we consider the evidence for
proposed "magneto-thermal evolution" in neutron stars, and argue that while
some exists, it is not yet conclusive.Comment: 6 pages, 4 figures, Conference proceeding of "ASTROphysics of Neutron
Stars 2010 -- a conference in honor of M. Ali Alpar", 2-6 August 2010, Cesme,
Izmir, Turke
A Search for Single Radio Pulses and Bursts from Southern AXPs
We observed four southern AXPs in 1999 near 1400 MHz with the Parkes 64-m
radio telescope to search for periodic radio emission. No Fourier candidates
were discovered in the initial analysis, but the recent radio activity observed
for the AXP XTE J1810-197 has prompted us to revisit these data to search for
single radio pulses and bursts. The data were searched for both persistent and
bursting radio emission at a wide range of dispersion measures, but no
detections of either kind were made. These results further weaken the proposed
link between rotating radio transient sources and magnetars. However, continued
radio searches of these and other AXPs at different epochs are warranted given
the transient nature of the radio emission seen from XTE J1810-197, which until
very recently was the only known radio-emitting AXP.Comment: 3 pages, including 1 table. To appear in the proceedings of "40 Years
of Pulsars: Millisecond Pulsars, Magnetars, and More", August 12-17, 2007,
McGill University, Montreal, Canad
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