Anomalous X-ray pulsar
Wiley Book of Astronomy:
Top
anomalous X-ray pulsar
anomalous X-ray pulsar (AXP)
A type of X-ray pulsar with a very long axial rotation period (for a pulsar), of 6 to 12 seconds, combined with a very powerful X-ray emission that cannot be explained by such a low spin rate. Two main theories exist to explain the anomalously powerful X rays. In the first model, bits of gas blown off in the supernova explosion that created the pulsar fall back onto the remnant star, whose magnetic field is assumed to be no stronger than an ordinary pulsar's. As the gas collects on the surface, it becomes hot and emits X rays. In the second model, which is now strongly supported by observation, AXPs are assumed to be magnetars—neutron stars with ultra-strong magnetic fields.
A type of X-ray pulsar with a very long axial rotation period (for a pulsar), of 6 to 12 seconds, combined with a very powerful X-ray emission that cannot be explained by such a low spin rate. Two main theories exist to explain the anomalously powerful X rays. In the first model, bits of gas blown off in the supernova explosion that created the pulsar fall back onto the remnant star, whose magnetic field is assumed to be no stronger than an ordinary pulsar's. As the gas collects on the surface, it becomes hot and emits X rays. In the second model, which is now strongly supported by observation, AXPs are assumed to be magnetars—neutron stars with ultra-strong magnetic fields.
Wikipedia on Answers.com:
Top
Anomalous X-ray pulsar
Anomalous X-ray Pulsars (AXPs) are now widely believed to be magnetars—young, isolated, highly magnetized neutron stars. These energetic X-ray pulsars are characterized by slow rotation periods of ~2–12 seconds and large magnetic fields of ~1013–1015 gauss (1 to 100 gigateslas). There are currently (as of 2009[update]) 9 known and 1 candidate AXPs.[1] The identification of AXPs with magnetars was motivated by their similarity to another enigmatic class of sources, the soft gamma repeaters.
| A list of AXP candidates and their estimated rotation period in seconds, as of 2003, follows: | ||
| AXP 1E 2259+586 | 6.98 | |
| AXP 1E 1048-59 | 6.45 | |
| AXP 4U 0142+61 | 8.69 | |
| AXP 1RXS 1708-40 | 11.0 | |
| AXP 1E 1841-045 | 11.8 | |
| AXP AXJ1844-0258 | 6.97 | |
| AXP CXJ0110-7211 | 5.44 | |
| Please note that the second, fourth, and last names were abbreviated | ||
References
- ^ SGR/AXP Online Catalog (An online catalog of SGR/AXP properties maintained by the pulsar group at McGill University)
External links
- Meissner Effect in Quark Stars (University of Calgary)
- "Magnetars" (Paper from a March 1995 conference proceedings, with first use of the term "AXP" and suggestion that AXPs are magnetars.)
 |
This variable star–related article is a stub. You can help Wikipedia by expanding it. |
This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
Post a question - any question - to the WikiAnswers community:
Copyrights:
Wiley Book of Astronomy
Copyright © 2004 by Wiley-Blackwell. Wiley and the Wiley logo are registered trademarks of John Wiley & Sons, Inc. and/or its affiliates in the United States and other countries. Used here by license. Read more
