TITLE: GCN CIRCULAR NUMBER: 25904 SUBJECT: LIGO/Virgo S190814bv: VLA 6 GHz observations of 75 galaxies in the 90% localization region DATE: 19/10/01 18:21:40 GMT FROM: Kate Alexander at Northwestern U K. D. Alexander, G. Schroeder, W. Fong, R. Margutti, (Northwestern), P. S. Cowperthwaite (Carnegie), E. Berger (Harvard), D. L. Coppejans (Northwestern), T. Laskar (University of Bath), A. MacFadyen (NYU), B. D. Metzger (Flatiron CCA, Columbia), G. Terreran (Northwestern), V. Ashley Villar (Harvard), and X. Xie (University of Southampton) report on behalf of a larger collaboration: We observed 75 galaxies within the 90% localization region of S190814bv (LIGO/Virgo et al., GCN 25324) with the Karl G. Jansky Very Large Array (VLA, program 19A-258, PI: Alexander). Observations were performed at a mean frequency of 6 GHz in a series of three observing blocks, with an average of 6.3 min of on-source time per galaxy. The observations were taken at mid-times of 34.4, 37.5, and 38.5 days after the merger. The galaxies were selected from the GLADE catalog (Dálya et al. 2018) using a priority ranking that combines each galaxy’s position within the 3D localization volume and its absolute magnitude in the B-band. Our observations covered 20% of the total integrated B-band luminosity within the localization volume. We created a 7 x 7 arcmin image centered on each galaxy, covering the VLA primary beam out to the half power radius. Pointing centers are listed below. Preliminary visual inspection yields detections of radio sources at or near the positions of 19 galaxies (representing 25% of our sample). The average 3-sigma limit at the center of our images is ~35 microJy. Further observations are planned to assess variability of any detected sources, and/or to detect any new sources on these timescales. We thank the VLA staff for their assistance in planning and executing these observations. Pointing Centers (RA, Dec J2000): 11.781363 -24.370647 12.180364 -23.561686 12.091079 -25.126814 11.870618 -25.440655 12.25617 -23.811317 13.173257 -25.733852 13.601437 -25.464052 12.874431 -24.642494 13.806392 -26.321253 12.828166 -26.16806 12.441799 -26.443037 12.793847 -25.954172 13.704722 -26.371256 11.543399 -24.650192 12.364808 -26.538301 11.771893 -24.238703 12.2428 -25.69345 12.178233 -23.773075 12.320091 -26.219179 13.788131 -25.455704 12.22897 -25.069471 12.473102 -24.707197 12.103154 -25.595707 12.311129 -23.858547 12.740481 -23.557995 13.490571 -24.543142 12.643789 -23.618547 11.472051 -23.772461 13.65696 -25.067099 12.42386 -25.050814 12.800914 -26.313063 11.867466 -23.02301 13.299205 -26.093979 12.726862 -23.631887 12.540436 -23.280048 13.804421 -24.044033 13.267828 -26.170792 13.064037 -24.69873 12.838246 -26.98945 12.346334 -26.507498 13.269273 -24.704401 12.551639 -25.975159 12.666141 -26.813395 12.385612 -26.538588 12.637869 -23.295488 11.9691 -25.8414 12.332034 -26.476397 13.477119 -24.077032 13.192388 -22.975018 13.358978 -26.599817 12.881038 -26.077213 11.7816 -25.66073 12.827568 -26.345284 11.264906 -25.019766 12.4675 -25.94625 13.3536 -25.8268 12.525684 -25.957939 12.808345 -26.461119 12.7184 -25.57706 11.054956 -24.327574 13.149672 -26.750933 11.555073 -25.950188 12.9027 -25.94219 13.566429 -23.535162 13.194542 -25.671635 12.6371 -25.95719 23.594837 -32.835316 11.3958 -24.24854 12.174922 -23.368631 13.570972 -23.552662 12.639195 -23.016602 13.522819 -23.194635 14.254662 -23.837297 12.8157 -25.9609 11.442945 -25.920193