TITLE: GCN CIRCULAR NUMBER: 19540 SUBJECT: LIGO/Virgo G211117/GW151226: serendipitous XMM-Newton slew observations DATE: 16/06/16 19:31:59 GMT FROM: Eleonora Troja at GSFC A. M. Read (U. Leicester), A. Tiengo (IUSS Pavia), R. Salvaterra (INAF-IASF Milano), E. Troja (NASA/GSFC), R. D. Saxton (ESAC) report: We analyzed the XMM-Newton slews made in the two weeks after the LIGO/Virgo G211117 / GW151226 event. Five slews intercept the BAYESTAR localization map in this period of time for a total coverage of about 26 square degrees: Obs ID | date | T-T_GW |coverage of localization map 9294000002 | 2015-12-28 | 2.7 d | 3 deg2 9294300002 | 2016-01-03 | 8.7 d | 4 deg2 9294400002 | 2016-01-06 | 11.6 d | 2 deg2 9294500002 | 2016-01-08 | 13.6 d | 2 deg2 9294600002 | 2016-01-10 | 15.5 d | 15 deg2 For each dataset (EPIC pn data with the Medium filter) we performed the source detection following the method described in Troja et al. 2016 (ApJ, 822, L8). Typical sensitivity limits of slew observations are ~6e-13 ergs cm-2 s-1 in the 0.2-2 keV band and ~4e-12 ergs cm-2 s-1 in the 2-12 keV band. The list of the most significant 0.2-12 keV band detections (DET_ML>12) in each slew intersecting the GW151226 localization map with no counterpart within 30 arcsec in the ROSAT All Sky Survey (Boller et al. 2016, A&A 588, A103) is reported below. The flux and counts are computed in the 0.2-12 keV energy band. ---------- Revolution 2940, Observation ID 9294000002 RA (deg) DEC (deg) POS_ERR (") CTS CTS_ERR DET_ML EXPOSURE (s) FLUX (ergs cm-1 s-1) 27.3262 -1.1849 4.1 6.2 2.6 20.1 12.0 5.2e-12 ---------- Revolution 2943, Observation ID 9294300002 RA (deg) DEC (deg) POS_ERR (") CTS CTS_ERR DET_ML EXPOSURE (s) FLUX (ergs cm-1 s-1) 15.6690 -20.0254 3.3 6.6 2.8 18.7 7.8 8.5e-12 14.6309 -17.6256 4.7 4.8 2.4 12.9 3.3 1.4e-11 ---------- Revolution 2944, Observation ID 9294400002 RA (deg) DEC (deg) POS_ERR (") CTS CTS_ERR DET_ML EXPOSURE (s) FLUX (ergs cm-1 s-1) Notes 186.5515 5.5650 5.1 5.0 2.4 14.8 9.4 5.3e-12 Detected also in Revolution 2945 186.7524 6.0297 3.5 4.8 2.3 17.9 11.3 4.2e-12 186.2499 5.0154 4.5 4.7 2.3 13.7 10.8 4.3e-12 185.0333 2.4117 4.2 7.8 3.0 20.0 6.2 1.2e-11 ---------- Revolution 2945, Observation ID 9294500002 RA (deg) DEC (deg) POS_ERR (") CTS CTS_ERR DET_ML EXPOSURE (s) FLUX (ergs cm-1 s-1) Notes 186.5545 5.5635 3.3 8.6 3.0 34.1 8.8 9.8e-12 Detected also in Revolution 2944 186.9961 6.5894 3.6 4.5 2.2 18.6 13.4 3.3e-12 186.6783 5.9833 5.2 5.5 2.5 16.8 12.0 4.5e-12 185.7506 3.7284 5.4 4.4 2.2 14.4 10.3 4.3e-12 ---------- Revolution 2946, Observation ID 92946 00002 RA (deg) DEC (deg) POS_ERR (") CTS CTS_ERR DET_ML EXPOSURE (s) FLUX (ergs cm-1 s-1) 187.2622 7.6581 4.5 8.2 3.2 12.4 5.8 1.4e-11 192.9292 -2.5083 4.9 5.7 2.6 15.4 5.5 1.0e-11 201.3687 -17.3449 8.7 4.9 2.3 12.5 8.0 6.2e-12