Anomalous X-ray pulsar
Encyclopedia
Anomalous X-ray Pulsars are now widely believed to be magnetar
s—young, isolated, highly magnetized neutron star
s. These energetic X-ray pulsar
s are characterized by slow rotation periods of ~2–12 seconds and large magnetic field
s of ~1013–1015 gauss
(1 to 100 gigateslas). There are currently 9 known and 1 candidate AXPs. The identification of AXPs with magnetars was motivated by their similarity to another enigmatic class of sources, the soft gamma repeater
s.
Magnetar
A magnetar is a type of neutron star with an extremely powerful magnetic field, the decay of which powers the emission of copious high-energy electromagnetic radiation, particularly X-rays and gamma rays...
s—young, isolated, highly magnetized neutron star
Neutron star
A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star during a Type II, Type Ib or Type Ic supernova event. Such stars are composed almost entirely of neutrons, which are subatomic particles without electrical charge and with a slightly larger...
s. These energetic X-ray pulsar
X-ray pulsar
X-ray pulsars or accretion-powered pulsars are a class of astronomical objects that are X-ray sources displaying strict periodic variations in X-ray intensity...
s are characterized by slow rotation periods of ~2–12 seconds and large magnetic field
Magnetic field
A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;...
s of ~1013–1015 gauss
Gauss (unit)
The gauss, abbreviated as G, is the cgs unit of measurement of a magnetic field B , named after the German mathematician and physicist Carl Friedrich Gauss. One gauss is defined as one maxwell per square centimeter; it equals 1 tesla...
(1 to 100 gigateslas). There are currently 9 known and 1 candidate AXPs. The identification of AXPs with magnetars was motivated by their similarity to another enigmatic class of sources, the soft gamma repeater
Soft gamma repeater
A soft gamma repeater is an astronomical object which emits large bursts of gamma-rays and X-rays at irregular intervals. It is conjectured that they are a type of magnetar or, alternatively, neutron stars with fossil disks around them....
s.
| 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 AXP 1E 1048-59 Anomalous X-ray pulsar 1E 1048.1-5937 was the first AXP ever observed to emit an SGR-like X-ray burst.... |
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 | ||
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.)