{
  "id": "1107.4050",
  "version": "v1",
  "published": "2011-07-20T17:54:09.000Z",
  "updated": "2011-07-20T17:54:09.000Z",
  "title": "Extended Tails from SGR 1806-20 Bursts",
  "authors": [
    "Ersin Gogus",
    "Peter Woods",
    "Chryssa Kouveliotou",
    "Mark H. Finger",
    "Valentin Pal'shin",
    "Yuki Kaneko",
    "Sergei Golenetskii",
    "Dmitry Frederiks",
    "Carol Airhart"
  ],
  "comment": "Accepted for publication in the ApJ",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "In 2004, SGR 1806-20 underwent a period of intense and long-lasting burst activity that included the giant flare of 27 December 2004 -- the most intense extra-solar transient event ever detected at Earth. During this active episode, we routinely monitored the source with Rossi X-ray Timing Explorer and occasionally with Chandra. During the course of these observations, we identified two relatively bright bursts observed with Konus-Wind in hard X-rays that were followed by extended X-ray tails or afterglows lasting hundreds to thousands of seconds. Here, we present detailed spectral and temporal analysis of these events observed about 6 and 1.5 months prior to the 27 December 2004 Giant Flare. We find that both X-ray tails are consistent with a cooling blackbody of constant radius. These spectral results are qualitatively similar to those of the burst afterglows recorded from SGR 1900+14 and recently from SGR 1550-5418. However, the latter two sources exhibit significant increase in their pulsed X-ray intensity following the burst, while we did not detect any significant changes in the RMS pulsed amplitude during the SGR 1806-20 events. Moreover, we find that the fraction of energy partitioned to the burst (prompt energy release) and the tail (afterglow) differs by an order of magnitude between SGR 1900+14 and SGR 1806-20. We suggest that such differences can be attributed to differences in the crustal heating mechanism of these neutron stars combined with the geometry of the emitting areas.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2011-07-20T17:54:09.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "extended tails",
      "giant flare",
      "intense extra-solar transient event",
      "x-ray tails",
      "rossi x-ray timing explorer"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1088/0004-637X/740/2/55",
      "journal": "The Astrophysical Journal",
      "year": 2011,
      "month": "Oct",
      "volume": 740,
      "number": 2,
      "pages": 55
    },
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 919259,
      "adsabs": "2011ApJ...740...55G"
    }
  }
}