{
  "id": "1008.1794",
  "version": "v2",
  "published": "2010-08-10T20:13:16.000Z",
  "updated": "2010-09-17T16:36:03.000Z",
  "title": "The Plerionic Supernova Remnant G21.5-0.9 Powered by PSR J1833-1034: New Spectroscopic and Imaging Results Revealed with the Chandra X-ray Observatory",
  "authors": [
    "Heather Matheson",
    "Samar Safi-Harb"
  ],
  "comment": "Accepted by ApJ. 38 pages using aastex.cls - including 4 tables and 14 figures (figures 1, 2, and 10-13 are in colour). Resolution of figures 1, 10, 11, and 13 have been reduced for astro-ph submission only. The original full-resolution version can be downloaded from: http://www.physics.umanitoba.ca/~samar/ms-G21.pdf",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "(Abridged) In 1999, Chandra revealed a 150\"-radius X-ray halo surrounding the 40\"-radius PWN G21.5-0.9. A 2005 imaging study showed that the halo is limb-brightened, and suggested this feature is a candidate for the long-sought SNR shell. We present a spectral analysis of G21.5-0.9, using the longest effective observation to date (578.6 ks with ACIS, 278.4 ks with HRC) to study unresolved questions about the spectral nature of remnant features, such as the limb-brightening of the X-ray halo and the bright knot in the northern part of the halo. The Chandra analysis favours the non-thermal interpretation of the limb. Its spectrum is well fit with a power-law model with a photon index $\\Gamma$ = 2.13 (1.94-2.33) and a luminosity of L_x (0.5-8 keV) = (2.3 +/- 0.6) x 10^33 erg/s (at an assumed distance of 5.0 kpc). An srcut model was also used to fit the spectrum between radio and X-ray energies. We find that the maximum energy to which electrons are accelerated at the shock ranges from ~60-130 TeV (B/10$\\mu$G)^(-1/2), where B is the magnetic field in units of $\\mu$G. For the northern knot, we constrain previous models and find that a two-component power-law (or srcut) + pshock model provides an adequate fit, with the pshock model requiring a very low ionization timescale and solar abundances for Mg and Si. Our spectroscopic study of J1833-1034, the highly energetic pulsar powering G21.5-0.9, shows that its spectrum is dominated by hard non-thermal X-ray emission with some evidence of a thermal component that represents ~9% of the observed non-thermal emission and that suggests non-standard rapid cooling of the neutron star. Finally, the ACIS and HRC-I images provide the first evidence for variability in the PWN, a property observed in other PWNe such as the Crab and Vela.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2010-09-17T16:36:03.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "plerionic supernova remnant g21",
      "chandra x-ray observatory",
      "imaging results",
      "energetic pulsar powering g21",
      "spectroscopic"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1088/0004-637X/724/1/572",
      "journal": "The Astrophysical Journal",
      "year": 2010,
      "month": "Nov",
      "volume": 724,
      "number": 1,
      "pages": 572
    },
    "note": {
      "typesetting": "TeX",
      "pages": 38,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 864983,
      "adsabs": "2010ApJ...724..572M"
    }
  }
}