L. Guillemot, T. J. Johnson, C. Venter, M. Kerr, B. Pancrazi, M. Livingstone, G. H. Janssen, P. Jaroenjittichai, M. Kramer, I. Cognard, B. W. Stappers, A. K. Harding, F. Camilo, C. M. Espinoza, P. C. C. Freire, F. Gargano, J. E. Grove, S. Johnston, P. F. Michelson, A. Noutsos, D. Parent, S. M. Ransom, P. S. Ray, R. Shannon, D. A. Smith, G. Theureau, S. E. Thorsett, N. Webb
We report the detection of pulsed gamma-ray emission from the fast
millisecond pulsars (MSPs) B1937+21 (also known as J1939+2134) and B1957+20
(J1959+2048) using 18 months of survey data recorded by the \emph{Fermi} Large
Area Telescope (LAT) and timing solutions based on radio observations conducted
at the Westerbork and Nan\c{c}ay radio telescopes. In addition, we analyzed
archival \emph{RXTE} and \emph{XMM-Newton} X-ray data for the two MSPs,
confirming the X-ray emission properties of PSR B1937+21 and finding evidence
($\sim 4\sigma$) for pulsed emission from PSR B1957+20 for the first time. In
both cases the gamma-ray emission profile is characterized by two peaks
separated by half a rotation and are in close alignment with components
observed in radio and X-rays. These two pulsars join PSRs J0034-0534 and
J2214+3000 to form an emerging class of gamma-ray MSPs with phase-aligned peaks
in different energy bands. The modeling of the radio and gamma-ray emission
profiles suggests co-located emission regions in the outer magnetosphere.
View original:
http://arxiv.org/abs/1110.1271
No comments:
Post a Comment