TITLE: GCN CIRCULAR NUMBER: 21516 SUBJECT: LIGO/Virgo G298048: Potential host galaxies from the GLADE catalog DATE: 17/08/17 18:55:12 GMT FROM: Gergely Dalya at Eotvos U Gergely Dálya, Bence Bécsy and Peter Raffai (Eotvos U) reports on behalf of the GLADE team: We have found 15 galaxies in the GLADE catalog [1], within the 1 sigma GW localisation area reported by the LVC in GCN 21513, and within 40 +/- 8 Mpc distance limits. We used the localisation information obtained using data from H1, L1, and V1, without making any assumption on the orientation of the system (where the glitch coincident with the event in L1 have been removed in the analysis). The galaxies found are given in the following table, sorted based on their absolute B magnitudes (a proxy for BNS formation). All distances are luminosity distances. Note that there are 83 and 184 galaxies (not listed here) within a 50 Mpc distance limit, inside the 2 and 3 sigma localisation areas, respectively. RA[deg] Dec[deg] Distance [Mpc] app. B mag abs. B mag --------------------------------------------------------------------------- 194.366257 -19.691298 44.75 12.68 -20.574 196.89064 -24.008606 43.944 12.68 -20.5345 193.998657 -19.26899 41.944 13.27 -19.8433 197.018005 -23.796844 34.097 12.87 -19.7936 196.735474 -23.91707 33.653 13.07 -19.5651 196.774902 -23.67704 33.42 13.18 -19.44 196.907242 -23.57892 41.75 14.21 -18.8933 196.600052 -24.164007 33.431 13.78 -18.8407 196.907013 -23.938364 45.986 15.59 -17.7231 196.580811 -22.98033 39.361 15.71 -17.2653 194.55 -21.04596 41.778 15.96 -17.1447 196.348 -23.52258 39.583 16.1 -16.8875 196.354 -23.5025 43.583 16.88 -16.3166 196.892 -23.8152 42.855 17.4 -15.76 196.063 -22.8812 39.083 17.54 -15.4199 --------------------------------------------------------------------------- The total B luminosity of candidate galaxies exceeds by a factor of 4.5 the total B luminosity we would expect for the error volume from the average B luminosity of the local universe determined by Kopparapu et al. [2]. Based on this we assume that in fact the completeness of our galaxy sample within the volume is 100% in terms of integrated B luminosity. We have independently found 29 galaxies in the GLADE catalog within 40 +/- 8 Mpc distance limits, residing in the +/- 5 degree neighborhood of the IceCube neutrino candidate with Fermi GBM trigger 524666471/170817529 reported by Bartos et al. in GCN 21511. The galaxies found are given in the following table, sorted based on their absolute B magnitudes (a proxy for BNS formation). All distances are luminosity distances. RA[deg] Dec[deg] Distance [Mpc] app. B mag abs. B mag --------------------------------------------------------------------------- 177.21 -2.03229 40.365 13.00 -20.03 178.604523 -2.319723 41.306 13.79 -19.2901 178.419342 -3.996517 33.500 13.406 -19.2192 185.141 0.7882 33.153 13.77 -18.8326 185.274 0.55284 33.569 14.85 -17.7797 178.441 -8.01641 33.819 15.14 -17.5058 177.76 -4.08201 45.681 15.90 -17.3987 185.798 -3.49124 46.833 16.27 -17.0828 178.811 -6.45435 34.361 15.85 -16.8303 178.798 0.48769 46.990 16.69 -16.67 178.428 -1.65985 45.597 16.72 -16.5747 177.022 0.99129 43.194 16.96 -16.2171 178.548 -1.13135 45.75 17.12 -16.182 181.052 0.80256 41.236 17.02 -16.0564 185.169 -3.53346 45.708 17.58 -15.72 178.568 -4.63232 45.722 17.88 -15.4206 178.573 -4.02153 35.764 17.83 -14.9372 186.574 1.74166 34.806 17.81 -14.8983 185.791 0.4271 33.986 18.11 -14.5465 184.184 -2.8103 45.958 18.81 -14.5018 177.695 -3.2618 40.375 18.69 -14.3406 181.28 -0.11052 34.833 18.38 -14.33 180.632 -2.3032 40.083 18.71 -14.3048 178.049 0.74188 35.667 18.53 -14.2313 183.412 -1.29349 34.278 18.55 -14.1251 186.332 -1.599 34.833 18.77 -13.94 183.066 -0.56531 32.333 18.61 -13.9382 180.104 -4.9137 35.736 19.09 -13.6755 183.379 1.42761 42.8549 19.64 -13.52 --------------------------------------------------------------------------- [1] GLADE website: http://aquarius.elte.hu/glade/ [2] Kopparapu, R. K., Hanna, C., Kalogera, V., et al. 2008, ApJ, 675, 1459