LIGO/Virgo G299232: LOFAR follow-up
Abstract
From 2017 August 30 - September 4, we observed a large fraction of the localisation error range of the Advanced LIGO/Virgo trigger G299232 (LVC, GCN 21693) with the ILT (International Low-Frequency Array [LOFAR] Telescope). The observations were obtained with the high-band antennas (HBA) at a centre frequency of 145 MHz (bandwidth 15.8 MHz). We used 6 simultaneous beams on the sky, where each beam has a field of view of approximately 12 deg^2 (beam FWHM 3.9 deg). The observations cover roughly 300 deg^2 in total at optimum sensitivity. Each field was observed for 225 min using a number of separate 25-min snapshots. The beam centres are given below (RA and Dec in degrees); the Bayestar-HLV localisation was used as a basis for calculating the coordinates of the beams. Two beams in separate pointings were centred on the IceCube neutrino candidate at RA = 28.2 deg, Dec = 44.8 deg (Bartos et al., GCN 21694; Bartos et al., GCN 21698). Furthermore, one beam was centred on the optical transient discovered by Swift/UVOT at RA = 25.035625 deg, Dec = 34.567667 deg (Emery et al., GCN 21733). Analysis is ongoing. We thank the ASTRON Radio Observatory for promptly scheduling the observations. Pointing 1 (integration time 225 min over the period 2017-08-30 23:00 UTC - 2017-08-31 06:21 UTC) 1) 34.039151 46.299866 2) 35.248501 48.949799 3) 28.200000 44.800000 4) 31.322127 48.348415 5) 36.756176 44.251317 6) 37.965526 46.901250 Pointing 2 (integration time 225 min over the period 2017-08-30 23:26 UTC - 2017-08-31 06:47 UTC) 1) 35.780064 51.725205 2) 36.750925 54.437875 3) 31.502071 50.889684 4) 32.472933 53.602354 5) 39.087195 49.848056 6) 40.058057 52.560726 Pointing 3 (integration time 225 min over the period 2017-08-31 23:00 UTC - 2017-09-01 06:21 UTC) 1) 29.306644 35.778068 2) 30.478008 38.389034 3) 25.035625 34.567667 4) 27.105198 37.906547 5) 31.508089 33.649589 6) 32.679454 36.260555 Pointing 4 (integration time 225 min over the period 2017-08-31 23:26 UTC - 2017-09-01 06:47 UTC) 1) 31.825000 41.000000 2) 33.084178 43.610966 3) 28.199341 40.517513 4) 28.200000 44.800000 5) 34.191481 38.871521 6) 35.450659 41.482487 Pointing 5 (integration time 225 min over the period 2017-09-03 01:00-08:21 UTC) 1) 41.738945 68.095823 2) 43.350996 70.808493 3) 34.635623 67.260303 4) 36.247674 69.972972 5) 47.230217 66.218674 6) 48.842268 68.931344 Pointing 6 (integration time 225 min over the period 2017-09-03 01:26-08:47 UTC) 1) 44.937500 79.572222 2) 44.267884 76.796335 3) 31.320689 78.289239 4) 31.990306 81.065126 5) 57.884694 78.079318 6) 58.554311 80.855205 Pointing 7 (integration time 225 min over the period 2017-09-04 00:00-07:21 UTC) 1) 37.337896 57.197845 2) 38.228521 59.934164 3) 32.518303 56.247531 4) 33.408928 58.983851 5) 41.266865 55.411839 6) 42.157490 58.148159 Pointing 8 (integration time 225 min over the period 2017-09-04 00:26-07:47 UTC) 1) 39.119146 62.670484 2) 40.170071 65.406804 3) 33.432096 61.720170 4) 34.483021 64.456490 5) 43.755272 60.884478 6) 44.806196 63.620798
- Publication:
-
GRB Coordinates Network
- Pub Date:
- September 2017
- Bibcode:
- 2017GCN.21809....1B