{
  "bibcode": "2017GCN.21574....1K",
  "body": "D. Kaplan (UWM), T. Murphy (University of Sydney), K. Bannister (CSIRO), C. Lynch (University of Sydney), D. Dobie (University of Sydney) on behalf of the VAST collaboration.\n\nFollowing Bannister et al. (LVC GCN 21559), who reported ATCA detections of a radio source consistent with the position of NGC 4993 that is also seen with the VLA (Alexander et al. LVC GCN 21548), we present upper limits to the radio emission of any source at the position of the potential optical counterpart, SSS17a (Coulter et al., LVC GCN 21529).\n\nWe fit and subtracted a point-source at the optical position of NGC 4993 (13:09:47.706, -23:23:01.79; Skrutskie et al. 2003, 2MASS Extended Source Catalog).  The flux densities were consistent with the values reported by Bannister et al. (LVC GCN 21559).  We then measured the rms noise at the position of SSS17a as well as 3 other source-free positions nearby.  In all cases there was no detectable emission at the position of SSS17a (9.9 arcsec away), and the noise was essentially identical across all positions.  \n\nAssuming that all of the emission originates with the center of NGC 4993, our flux density for the galaxy and 3-sigma upper limits to emission at the position of SSS17a are:\n\nFrequency\tNGC 4993 Flux Density\t3-sigma Limit for SSS17a\n8.5 GHz: \t0.66 mJy\t\t\t120 uJy\n10.5 GHz:\t0.54 mJy\t\t\t150 uJy\n16.7 GHz: \t0.42 mJy\t\t\t130 uJy\n21.2 GHz: \t0.34 mJy\t\t\t140 uJy\n\nThank you to CSIRO staff for supporting these observations.",
  "circularId": 21574,
  "createdOn": 1503087540000,
  "email": "kaplan@uwm.edu",
  "subject": "LIGO/Virgo G298048: ATCA upper limits on radio emission from optical source SSS17a in NGC 4993",
  "submitter": "David Kaplan at UW-Milwaukee  <kaplan@uwm.edu>",
  "eventId": "LIGO/Virgo G298048"
}