[vsnet-grb-info 23805] LIGO/Virgo S190814bv: VLA 6 GHz observations of 75 galaxies in the 90% localization region

[GCN Circulars]

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  <kate.alexander at northwestern.edu>

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