{
  "bibcode": "2011GCN.12260....1H",
  "body": "GRB 110807A/SGR J1834.9-0846 (D'Elia et al., GCN 12253; Guiriec et al.,\nGCN 12255; Barthelmy et al., GCN 12259) is superposed on the supernova\nremnant W41 (G23.3-0.3), a location that has been well studied by XMM\n(Tian et al. 2007, ApJ, 657, L25; Mukherjee et al. 2009, ApJ, 691, 1707)\nand Chandra (Misanovic et al. 2011, ApJ, 735, 33).  W41 is also coincident\nwith the high-energy sources HESS J1834-087 and 2FGL J1834.3-0848.\nLeahy & Tian (2008, AJ, 135, 167) derived a kinematic distance of\n3.9-4.5 kpc to W41.\n\nSwift XRT quicklook data beginning 6.7 minutes after the trigger shows\nan absorbed source with an initial 2-10 keV flux of ~1 count/s, declining\nto a plateau of 0.16 counts/s during 1547 s of exposure spanning 1.5 hr.\nNo significant periodicity is present in this PC mode data for periods\nlonger than 2.5 s with a pulsed fraction limit of ~35%.  Due to the\nsmall number of counts (~330) and low time resolution, this is not very\nconstraining of an SGR.\n\nThere is another neutron star candidate, XMMU J183435.3-084443/\nCXOU J183434.9-084443, that lies 4.4 arcmin from the Swift XRT source\ncounterpart of SGR J1834.9-0846.  Also, the source cataloged as\n2XMM J183452.4-084603, which is 6.6 arcsec from the Swift XRT position\nas noted by D'Elia et al., is not a point source, but rather a patch\nof diffuse emission. There is no obvious X-ray point source in archival\nXMM or Chandra images at the Swift XRT location of the SGR.  See the\nabove references for further details.\n\nIn addition, the radio pulsar PSR J1833-0827, which lies 24' north of W41,\nhas a characteristic age of 1.5x10^5 yr and a proper motion of 33 mas/yr\naway from W41 (Hobbs et al. 2005, MNRAS, 360, 974).  It has been considered\nby several authors as possibly originating in W41.\n\nIn summary, GRB 110807A/SGR J1834.9-0846 can be considered a third\ncandidate for a neutron star that could be associated with W41.",
  "circularId": 12260,
  "createdOn": 1312812806000,
  "email": "jules@astro.columbia.edu",
  "subject": "SGR J1834.9-0846: A Neutron Star in W41?",
  "submitter": "Jules Halpern at Columbia U.  <jules@astro.columbia.edu>"
}