//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19023 SUBJECT: GRB 160220A: Swift detection of a burst DATE: 16/02/20 01:36:52 GMT FROM: David Palmer at LANL A. Y. Lien (GSFC/UMBC), P.A. Evans (U Leicester), J. A. Kennea (PSU), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the Swift Team: At 01:25:25 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 160220A (trigger=674670). Swift could not immediately slew to the burst. The BAT on-board calculated location is RA, Dec 236.925, -18.555 which is RA(J2000) = 15h 47m 42s Dec(J2000) = -18d 33' 17" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 15 sec. The peak count rate was ~500 counts/sec (15-350 keV), at ~5 sec after the trigger. Due to an observing constraint, Swift will not slew until T0+50.1 minutes. There will be no XRT or UVOT data until this time. Burst Advocate for this burst is A. Y. Lien (amy.y.lien AT nasa.gov). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19024 SUBJECT: GRB 160220A: Swift-XRT observations DATE: 16/02/20 03:13:49 GMT FROM: Phil Evans at U of Leicester S. Campana (INAF-OAB), G. Cusumano (INAF-IASF PA), P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), D.N. Burrows (PSU) and J.A. Kennea (PSU) report on behalf of the Swift-XRT team: The XRT began observing the field of GRB 160220A at 02:19:23.8 UT, 3238.1 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 236.95167, -18.56501 which is equivalent to: RA(J2000) = 15h 47m 48.40s Dec(J2000) = -18d 33' 54.0" with an uncertainty of 3.9 arcseconds (radius, 90% containment). This location is 97 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 1.09 x 10^21 cm^-2 (Willingale et al. 2013). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19025 SUBJECT: GRB 160220A: Enhanced Swift-XRT position DATE: 16/02/20 07:05:40 GMT FROM: Phil Evans at U of Leicester P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team. Using 1730 s of XRT Photon Counting mode data and 5 UVOT images for GRB 160220A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 236.95288, -18.56605 which is equivalent to: RA (J2000): 15h 47m 48.69s Dec (J2000): -18d 33' 57.8" with an uncertainty of 1.9 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19026 SUBJECT: GRB 160220A: Fermi GBM observation DATE: 16/02/20 07:21:32 GMT FROM: C. Michelle Hui at MSFC/Fermi-GBM C. M. Hui (NASA/MSFC) and E. Burns (UAH) report on behalf of the Fermi GBM Team: "At 01:25:26.968 UT on 20 February 2016, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 160220A (trigger 477624330 / 160220059), which was also detected by the Swift/BAT (Lien et al. 2016, GCN 19023). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time is 46 degrees. The GBM light curve shows a single peak with a duration (T90) of about 9 s (50-300 keV). The time-averaged spectrum from T0-3.072 s to T0+9.216 s is best fit by a simple power law function with index -1.5 +/- 0.1. The event fluence (10-1000 keV) in this time interval is (1.2 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+2.43 s in the 10-1000 keV band is 1.7 +/- 0.2 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19027 SUBJECT: GRB 160220A: GROND Optical/NIR Upper Limits DATE: 16/02/20 08:06:33 GMT FROM: Philip Wiseman at MPE/Swift P. Wiseman, F. Knust, J. Greiner (all MPE Garching) report on behalf of the GROND team: We observed the field of GRB 160220A (Swift trigger 674670; Lien et al., GCN #19023) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2m MPG telescope at ESO La Silla Observatory (Chile). Observations started at 05:46 UT on 2016-02-20, 4.5 hrs after the GRB trigger. They were performed at an average seeing of 1.5" and at an average airmass of 1.6. We do not find any single point source within the 1.9" Enhanced Swift-XRT error circle reported by Evans et al. (GCN #19025). Based on 36.00 min of total exposures in g'r'i'z' and 30.00 min in JHK, at a mid-time of 06:49 UT, we estimate preliminary upper limiting magnitudes (AB system) of g' > 23.4 mag, r' > 23.9 mag, i' > 23.6 mag, z' > 23.3 mag, J > 21.6 mag, H > 20.9 mag, and K > 18.0 mag. Given limits are calibrated against GROND zeropoints as well as 2MASS field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.12 mag in the direction of the burst (Schlafly & Finkbeiner 2011). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19028 SUBJECT: GRB 160220A: MASTER-Amur observations DATE: 16/02/20 09:39:50 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs D.Buckley, S. Potter, M.Kotze South African Astronomical Observatory A.Gabovich, V.Yurkov, Yu.Sergienko, D.Varda Blagoveschensk Educational State University, Blagoveschensk E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, N.Tyurina, P.Balanutsa, A.Kuznetsov Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow State University K.Ivanov, N.M.Budnev, O.Gres, V.A.Poleshchuk Irkutsk State University A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory R. Rebolo, M. Serra-Ricart, N. Lodieu, G. Israelian The Instituto de Astrofisica de Canarias MASTER-SAAO robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in SAAO was pointed to the GRB160220A (Lien et al., GCN #19023) 22 sec after notice time and 65 sec after trigger time at 2016-02-20 01:26:34 UT. On our first (10s exposure) set we haven`t found optical transient within SWIFT error-box (ra=15 47 41 dec=-18 33 16 r=0.050000). The 5-sigma upper limit has been about 15.5mag The automatically generated table image limits you can see below: Pro.ID Pro.type time Exp. Limit Filt. Tube UT s mag polaroid 162238 Alert 01:26:34 10 15.5 P/ EAST 162239 Alert 01:26:34 10 15.5 P\ WEST 162240 Alert 01:26:56 20 14.8 P/ EAST 162241 Alert 01:26:56 20 14.8 P\ WEST 162241 Alert 01:26:56 20 14.8 P\ WEST 162242 Alert 01:27:29 20 16.7 P/ EAST 162243 Alert 01:27:29 20 16.6 P\ WEST 162244 Alert 01:28:02 30 17.9 P/ EAST 162245 Alert 01:28:02 30 17.9 P\ WEST 162246 Alert 01:28:44 40 16.5 P/ EAST 162247 Alert 01:28:44 40 16.4 P\ WEST 162264 SumAlert 01:26:56 70 17.7 P/ EAST 162265 SumAlert 01:26:56 70 17.8 P\ WEST 162266 SumAlert 01:28:44 150 18.2 P/ EAST 162267 SumAlert 01:28:44 150 18.3 P\ WEST 162323 SumAlert 01:26:56 670 19.3 P/ EAST 162321 SumAlert 01:26:56 670 19.1 P\ WEST ........ 162338 SumAlert 01:40:23 1800 19.4 P/ EAST 162337 SumAlert 01:40:23 1800 19.2 P\ WEST The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19030 SUBJECT: GRB 160220A: TAROT Calern and TAROT La Silla observatory optical observations DATE: 16/02/20 13:43:43 GMT FROM: Alain Klotz at IRAP-CNRS-OMP Klotz A., Turpin D., Atteia J.L. (CNRS-OMP-IRAP), Boer, M., Laugier, R. (CNRS-ARTEMIS), Gendre B. (UVI - Etelman Obs.) report: We imaged the field of GRB 160220A detected by SWIFT (trigger 674670) with the TAROT robotic telescopes (D=25cm) located at the Calern observatory, France and at the European Southern Observatory, La Silla observatory, Chile. The observations started 1.64h after the GRB trigger at Calern and 4.00h after the GRB trigger at la Silla (the field was not visible at the date of the trigger). The elevation of the field increased from 20 degrees above horizon and weather conditions were good. We co-added a series of exposures. We do not detected the X-ray couterpart mentioned by Campana et al. (GCNC 19024): t1(h) t2(h) Rmag_lim Site 1.64 3.30 17.5 TAROT Calern 4.00 4.69 19.0 TAROT La Silla Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19032 SUBJECT: GRB160220A: Swift/UVOT observations DATE: 16/02/20 17:34:42 GMT FROM: Massimiliano de Pasquale at IASF-Palermo M. De Pasquale (MSSL-UCL) and A. Lien (GSFC/UMBC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 160220A 4.11 ks after the BAT trigger (Lien et al., GCN Circ. 19023). No optical afterglow consistent with the XRT position (Evans et al. GCN Circ. 19025) is detected in the UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the summed UVOT exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white 4110 5493 344 >20.6 v 4268 34517 903 >19.4 b 5088 5288 197 >19.7 u 4882 17290 424 >19.5 w1 4678 17052 1175 >20.3 m2 4472 11445 1271 >20.3 w2 5499 32840 1177 >20.5 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.13 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19038 SUBJECT: GRB 160220A: Swift-BAT refined analysis DATE: 16/02/20 21:43:14 GMT FROM: Hans Krimm at NASA-GSFC H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 160220A (trigger #674670) (Lien, et al., GCN Circ. 19023). The BAT ground-calculated position is RA, Dec = 236.942, -18.539 deg which is RA(J2000) = 15h 47m 46.2s Dec(J2000) = -18d 32' 20.6" with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 26%. The mask-weighted light curve shows a single peak of about 20 seconds total duration starting at ~0 sec. The spacecraft slewed away from the burst location at ~T+220 sec due to a pre-planned maneuver. T90 (15-350 keV) is 8.3 +- 1.2 sec (estimated error including systematics). The time-averaged spectrum from T-0.02 to T+8.99 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.55 +- 0.24. The fluence in the 15-150 keV band is 5.2 +- 0.7 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+0.33 sec in the 15-150 keV band is 1.0 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/674670/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19039 SUBJECT: GRB 160220A: Swift-XRT refined Analysis DATE: 16/02/20 22:09:50 GMT FROM: Phil Evans at U of Leicester A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), T.G.R. Roegiers (PSU), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), S.L. Gibson (U. Leicester), P. D'Avanzo (INAF-OAB) and A.Y. Lien report on behalf of the Swift-XRT team: We have analysed 7.7 ks of XRT data for GRB 160220A (Lien et al. GCN Circ. 19023), from 4.1 ks to 63.2 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN Circ. 19025). The light curve can be modelled with a power-law decay with a decay index of alpha=0.94 (+0.20, -0.18). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.67 (+0.37, -0.18). The best-fitting absorption column is consistent with the Galactic value of 1.1 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.0 x 10^-11 (4.6 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.1 (+/-1.1) x 10^21 cm^-2 Galactic foreground: 1.1 x 10^21 cm^-2 Excess significance: <1.6 sigma Photon index: 1.67 (+0.37, -0.18) If the light curve continues to decay with a power-law decay index of 0.94, the count rate at T+24 hours will be 3.9 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.5 x 10^-13 (1.8 x 10^-13) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00674670. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19040 SUBJECT: GRB 160220A: nIR observations at AAT DATE: 16/02/20 22:50:57 GMT FROM: Rhaana Starling at U of Leicester R. Starling, N. Tanvir, K. Wiersema (U. Leicester) and J. Bailey (UNSW) report on behalf of a larger collaboration: We observed the field of GRB 160220A (Swift trigger 674670, Lien et al. GCN Circ. 19023; Fermi trigger 477624330/16022005, Hui & Burns GCN Circ. 19026) with the 4m Anglo Australian Telescope, AAT, at Siding Spring, Australia on 2016 February 20th, 14 hours after burst. We obtained near-IR photometry with the Infrared Imager and Spectrograph, IRIS2, in the Ks band beginning at 15:35 UT and in the J band beginning 16:09 UT, and totalling 27 minutes exposure in each filter. No source was detected within the Swift XRT error circle (Evans et al. GCN Circ. 19025). We find the following approximate limiting magnitudes (at 5-sigma in the Vega system): J > 21 Ks > 18 We acknowledge excellent support from the Australian Astronomical Observatory staff.