2001/11/29 by J. P. Halpern, Halpern, J. P., E. V. Gotthelf +8
Engineering · Physics and Astronomy · #Astronomical Observations and Instrumentation #Astrophysical Phenomena and Observations #Astrophysics (astro-ph) #FOS: Physical sciences #Pulsars and Gravitational Waves Research #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0111577
6 pages, 4 figures, to appear in "Neutron Stars in Supernova Remnants" (ASP Conference Proceedings), eds P.O. Slane and B.M. Gaensler
openalex publication_date 2001/11/29 · arxiv created 2001/11/30 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
With a period of 51.6 ms and spin-down power 2.2x1037 erg s-1, PSR\nJ2229+6114 is a compelling identification for the EGRET source 3EG J2227+6122\nin which error circle it resides. Striking features of the Chandra X-ray image\nare an incomplete elliptical arc and a possible jet, similar to the structures\nthat dominate the appearance of the Vela PWN. Approximately 70% of the 2-10 keV\nX-ray emission comes from a centrally peaked, diffuse nebula of radius 100"\nwith a power-law spectrum of photon index 1.45 +/- 0.19. The pulsar itself has\na marginally harder spectrum with photon index 0.99 +/- 0.27. For an assumed\ndistance of 3 kpc the ratio of X-ray luminosity to spin-down power of PSR\nJ2229+6114 is only 8 x 10-5. We discuss a model in which such inefficient\nX-ray emission is the signature of a highly magnetized pulsar wind that\nprevents an internal MHD shock, at the location of the X-ray arc, from strongly\ncompressing the flow. The incomplete X-ray arc is consistent with beaming from\na relativistic equatorial outflow, while a surrounding radio shell is probably\nthe forward shock in the surrounding ISM. An MeV source at this location was\npreviously detected by the COMPTEL experiment on CGRO. This, plus the flat\nX-ray spectrum in the 2-10 keV band, suggests that PSR J2229+6114 is one of the\nbrightest pulsars at 1 MeV, even while it is inconspicuous at radio through\nX-ray wavelengths, and as steep as the Crab above 100 MeV. The apparent variety\nof broad-band spectra displayed by high-energy pulsars bolsters the theory that\nrotation-powered pulsars dominate the unidentified Galactic EGRET source\npopulation.\n