PSR J1833-1034: Discovery of the Central Young Pulsar in the Supernova Remnant G21.5-0.9
Abstract
We have discovered the pulsar associated with the supernova remnant G21.5-0.9. PSR J1833-1034, with spin period P=61.8 ms and dispersion measure 169 cm-3 pc, is very faint, with pulse-averaged flux density of ~70 μJy at a frequency of 1.4 GHz, and was first detected in a deep search with the Parkes telescope. Subsequent observations with Parkes and the Green Bank Telescope have confirmed this detection and yield a period derivative P˙=2.02×10-13. These spin parameters imply a characteristic age τc=4.8 kyr and a spin-down luminosity E˙=3.3×1037 ergs s-1, the latter value exceeded only by the Crab pulsar among the rotation-powered pulsars known in our Galaxy. The pulsar has an unusually steep radio spectrum in the 0.8-2.0 GHz range, with power-law index ~3.0, and a narrow single-peaked pulse profile with FWHM of 0.04P. We have analyzed 350 ks of archival Chandra X-Ray Observatory HRC data and find a pointlike source of luminosity ~3×10-5E˙, offset from the center of an elliptical region of size ~7''×5'' and luminosity ~10-3E˙ within which likely lies the pulsar wind termination shock. We have searched for X-ray pulsations in a 30 ks HRC observation without success, deriving a pulsed fraction upper limit for a sinusoidal pulse shape of about 70% of the pulsar flux. We revisit the distance to G21.5-0.9 based on H I and CO observations, arguing that it is 4.7+/-0.4 kpc. We use existing X-ray and radio observations of the pulsar wind nebula, along with the measured properties of its engine and a recent detection of the supernova remnant shell, to argue that G21.5-0.9 and PSR J1833-1034 are much younger than τc and likely their true age is <~1000 yr. In that case, the initial spin period of the pulsar was >~55 ms.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 2006
- DOI:
- 10.1086/498386
- arXiv:
- arXiv:astro-ph/0509823
- Bibcode:
- 2006ApJ...637..456C
- Keywords:
-
- ISM: individual (G21.5-0.9);
- pulsars: individual (PSR J1833-1034);
- Stars: Neutron;
- ISM: Supernova Remnants;
- Astrophysics
- E-Print:
- To appear in ApJ (submitted 2005 May 22