PSR J1856+0245: Arecibo Discovery of a Young, Energetic Pulsar Coincident with the TeV γ-Ray Source HESS J1857+026
Abstract
We present the discovery of the Vela-like radio pulsar J1856+0245 in the Arecibo PALFA survey. PSR J1856+0245 has a spin period of 81 ms, a characteristic age of 21 kyr, and a spin-down luminosity Ė = 4.6 × 1036 ergs s-1. It is positionally coincident with the TeV γ-ray source HESS J1857+026, which has no other known counterparts. Young, energetic pulsars create wind nebulae, and more than a dozen pulsar wind nebulae have been associated with very high energy (100 GeV-100 TeV) γ-ray sources discovered with the HESS telescope. The γ-ray emission seen from HESS J1857+026 is potentially produced by a pulsar wind nebula powered by PSR J1856+0245; faint X-ray emission detected by ASCA at the pulsar's position supports this hypothesis. The inferred γ-ray efficiency is epsilonγ = Lγ/Ė =3.1 % (1-10 TeV, for a distance of 9 kpc), comparable to that observed in similar associations.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 2008
- DOI:
- 10.1086/590908
- arXiv:
- arXiv:0806.1200
- Bibcode:
- 2008ApJ...682L..41H
- Keywords:
-
- gamma rays: observations;
- pulsars: general;
- pulsars: individual: PSR J1856&plus0245;
- stars: neutron;
- X-rays: individual: AX J185651&plus0245;
- Astrophysics
- E-Print:
- 13 pages, 1 figure, accepted for publication in The Astrophysical Journal Letters