TITLE: GCN CIRCULAR NUMBER: 21628 SUBJECT: LIGO/Virgo G298048: ATCA 8.5 GHz observations of galaxies in the localisation volume DATE: 17/08/21 07:45:30 GMT FROM: Tara Murphy at U of Sydney C. Lynch (University of Sydney), T. Murphy (University of Sydney), D. Kaplan (UWM), K. Bannister (CSIRO), D. Dobie (University of Sydney) on behalf of the VAST collaboration. We have observed 54 galaxies in the localisation volume of G298048 as listed by Cook et al. (LVC GCN 21519) with the Australia Telescope Compact Array at 8.5 GHz (Bannister et al. LVC GCN 21537). The observations were taken in the EW352 configuration, with approximately 1-2 minutes on each source between 2017-08-18 01:00 UT and 2017-08-18 09:14:15 UT. We detected 8.5 GHz radio emission from 5 galaxies, as listed below: Galaxy 3-sigma flux density UGCA 331 0.33 mJy NGC 4993 0.66 mJy NGC 4968 16.1 mJy IC 4197 2.7 mJy ESO 508- G 033 3.7 mJy The rest of the sources in the list were non-detections. We list 3-sigma upper limits on the 8.5 GHz radio emission below: Galaxy 3-sigma flux density limit IC 3825 102.8 uJy ABELL 1631:[CZ2003]B0295[024] 47.1 uJy GALEXASC J125157.02-160617.8 43.7 uJy MCG -02-33-036 24.9 uJy 2MASX J12525109-1529300 33.2 uJy GALEXASC J125301.39-151007.7 36.9 uJy WINGS J125412.84-153523.6 25.9 uJy 6dF J1254495-160308 36.2 uJy GALEXASC J125520.46-170546.9 33.6 uJy HIPASS J1255-15 36.5 uJy ESO 575- G 029 46.8 uJy MCG -03-33-023 198.8 uJy WINGS J125701.38-172325.2 213.4 uJy NGC 4830 60.0 uJy GALEXASC J125811.97-210246.3 22.6 uJy GALEXASC J130415.26-225251.3 21.2 uJy ESO 575- G 053 50.4 uJy 6dF J1305235-233121 18.2 uJy GALEXASC J130525.30-233008.8 12.8 uJy 2MASX J13061939-2258491 77.5 uJy ESO 508- G 003 60.3 uJy ESO 575- G 055 85.7 uJy ESO 508- G 004 66.2 uJy UGCA 325 35.0 uJy GALEXASC J130707.37-240634.4 35.0 uJy NGC 4970 48.5 uJy ABELL 1664_11:[PSE2006] 2506 54.7 uJy ESO 508- G 010 39.2 uJy UGCA 327 39.8 uJy USGC S204 44.5 uJy HDCE 0763 39.2 uJy ESO 508 62.8 uJy ESO 508- G 014 56.0 uJy 2MFGC 10461 44.3 uJy 6dF J1309177-242256 24.6 uJy GALEXASC J130918.58-242304.8 25.6 uJy UGCA 328 23.1 uJy ESO 576- G 003 49.4 uJy [TSK2008] 0073 32.2 uJy GALEXASC J131426.62-271242.6 53.4 uJy [TSK2008] 0052 56.6 uJy ESO 508- G 035 70.5 uJy We have not yet been able to make reliable measurements for the following 7 sources, so they are excluded from the above lists: 2MASX J12505229-1454238 2MASX J12573271-1942006 2MASX J13073768-2356181 GALEXASC J125259.36-152150.9 IC 4180 2MFGC 10484 ESO 508- G 019 We did not observe GALEXASC J120652.88-040236.6. Further observations are underway. Thank you to CSIRO staff for supporting these observations.