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Transient pulsed radio emission from a magnetar
Fernando Camilo1, Scott M Ransom, Jules P Halpern
1Columbia Astrophysics Laboratory, Columbia University, 550 West 120th Street, New York, New York 10027, USA. fernando@astro.columbia.edu
Nature
|August 25, 2006
Summary
Anomalous X-ray pulsars (AXPs), or magnetars, have been shown to emit radio pulses, a first for these objects. This discovery links magnetars to ordinary pulsars and opens new avenues for studying their magnetic fields and coronae.
Area of Science:
- * Astronomy and Astrophysics
- * High-Energy Astrophysics
- * Neutron Star Physics
Background:
- * Anomalous X-ray pulsars (AXPs) are neutron stars with ultra-strong magnetic fields (>10^14 G), known as magnetars.
- * Magnetars exhibit bright, variable X-ray emission but have never been observed to emit radio pulsations, unlike ordinary pulsars.
- * XTE J1810-197, an AXP, showed a significant X-ray outburst in 2003, followed by a radio source detection.
Purpose of the Study:
- * To investigate the radio emission properties of the anomalous X-ray pulsar XTE J1810-197.
- * To determine if magnetars can exhibit radio pulsar behavior.
- * To connect magnetar observations with those of ordinary radio pulsars.
Main Methods:
- * Observation of radio pulsations from XTE J1810-197 using radio telescopes.
- * Analysis of the characteristics of the detected radio pulses, including polarization and flux.
- * Comparison of radio emission properties with those of ordinary pulsars and magnetars in quiescent states.
Main Results:
- * XTE J1810-197 was detected emitting bright, narrow, and highly linearly polarized radio pulses at every rotation.
- * No radio emission was observed from XTE J1810-197 before its 2003 X-ray outburst.
- * The radio flux of XTE J1810-197 varied daily and was nearly constant across radio frequencies, becoming the brightest neutron star known above 20 GHz.
Conclusions:
- * Magnetars can indeed function as radio pulsars, bridging the gap between magnetars and ordinary radio pulsars.
- * The findings rule out alternative accretion-based models for AXPs.
- * These observations provide crucial insights into the magnetospheric coronae of magnetars.
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