77 research outputs found
Fermi pulsar revolution
2009 has been an extraordinary year for gamma-ray pulsar astronomy and 2010
promises to be equally good. Not only have we registered an extraordinary
increase in the number of pulsars detected in gamma rays, but we have also
witnessed the birth of new sub-families: first of all, the radio-quiet gamma
pulsars and later an ever growing number of millisecond pulsars, a real
surprise. We started with a sample of 7 gamma-ray emitting neutron stars (6
radio pulsars and Geminga) and now the Fermi-LAT harvest encompasses 24
"Geminga-like" new gamma-ray pulsars, a dozen millisecond pulsars and about
thirty radio pulsars. Moreover, radio searches targeted to LAT unidentified
sources yielded 18 new radio millisecond pulsars, several of which have been
already detected also in gamma rays. Thus, currently the family of gamma-ray
emitting neutron stars seems to be evenly divided between classical radio
pulsars, millisecond pulsars and radio quiet neutron stars.Comment: High Time Resolution Astrophysics IV - The Era of Extremely Large
Telescopes-HTRA-IV Agios Nikolaos, Crete, Greece May 5-7 2010 to be published
in Po
Neutron Stars as Particle Accelerators
According to standard theoretical interpretations, in neutron stars’ magnetospheres particles are accelerated along
the magnetic field lines where the highly-magnetized surrounding o ers the ideal conditions to make them radiate
high-energy gamma-rays (E > 100 MeV) that bear the timing signature of their parent neutron star
HST Proper Motion confirms the optical identification of the nearby pulsar PSR 1929+10
We report on the proper motion measurement of the proposed optical
counterpart of the X-ray/radio pulsar PSR 1929+10. Using images obtained with
the HST/STIS (average epoch 2001.73) we computed a yearly displacement of +97
+/- 1 mas yr^{-1} in RA and +46 +/- 1 mas yr^{-1} in Dec since the epoch
(1994.52) of the original HST/FOC detection. Both the magnitude and direction
of the optical proper motion components are found to be fully consistent with
the most recent VLBA radio measurements. This result provides an unambiguous
confirmation of the pulsar optical identification. In addition, we have used
the combined STIS/FOC datasets to derive information on the pulsar spectrum,
which seems characterized by a power law component, apparently unrelated to the
X-ray emission.Comment: 12 pages, 3 figures, submitted to ApJ Letter
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