Astrophysical Journal Letters
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 γ = Lγ/Ė =3.1 % (1-10 TeV, for a distance of 9 kpc), comparable to that observed in similar associations.
"PSR J1856+0245: Arecibo Discovery of a Young, Energetic Pulsar Coincident with the TeV Gamma-ray Source HESS J1857+026" J. W. T. Hessels, D. J. Nice, B. M. Gaensler, V. M. Kaspi, D. R. Lorimer, D. J. Champion, A. G. Lyne, M. Kramer, J. M. Cordes, P. C. C. Freire, F. Camilo, S. M. Ransom, J. S. Deneva, N. D. R. Bhat, I. Cognard, F. Crawford, F. A. Jenet, L. Kasian, P. Lazarus, J. van Leeuwen, M. A. McLaughlin, I. H. Stairs, B. W. Stappers, & A. Venkataraman, Astrophysical Journal Letters, 682, L41 (2008).