//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15986 SUBJECT: GRB 140318A: Swift detection of a burst DATE: 14/03/18 00:35:21 GMT FROM: Jamie A. Kennea at PSU/Swift-XRT S. B. Cenko (GSFC), M. G. Bernardini (INAF-OAB), D. N. Burrows (PSU), P. D'Avanzo (INAF-OAB), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), A. Y. Lien (NASA/GSFC/ORAU), F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB), T. Sakamoto (AGU), B. Sbarufatti (INAF-OAB/PSU) and M. H. Siegel (PSU) report on behalf of the Swift Team: At 00:09:07 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 140318A (trigger=592204). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 184.053, +20.207 which is RA(J2000) = 12h 16m 13s Dec(J2000) = +20d 12' 27" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single peak structure with a duration of about 30 sec. The peak count rate was ~1320 counts/sec (15-350 keV), at ~5 sec after the trigger. The XRT began observing the field at 00:11:12.7 UT, 124.8 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 184.0906, 20.2080 which is equivalent to: RA(J2000) = +12h 16m 21.74s Dec(J2000) = +20d 12' 28.8" with an uncertainty of 6.9 arcseconds (radius, 90% containment). This location is 127 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy. The initial flux in the 2.5 s image was 3.63e-10 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 132 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. Results from the 2.7'x2.7' sub-image are not available at this time. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.02. Burst Advocate for this burst is S. B. Cenko (brad.cenko 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: 15987 SUBJECT: GRB 140318A: NOT detection of the afterglow DATE: 14/03/18 02:04:47 GMT FROM: Steve Schulze at U of Iceland S. Schulze (PUC and MCSS), T. Kruehler (ESO Chile), N. R. Tanvir (U Leicester), A. A. Djupvik (NOT), and P. Jakobsson (U Iceland) report on behalf of a larger collaboration: We observed the field of GRB 140318A (Cenko et al., GCN 15986) with 2.5m the Nordic Optical Telescope (NOT) equipped with StanCAM. We obtained 3 x 300 s in the R band. Observations started at 00:52:00 UT on March 18 (i.e. 43 min after the burst). We detect a bright point source at the position R.A.(J2000) = 12:16:21.40 Dec. (J2000) = +20:12:31.9 We measure R = 19.7 +/- 0.1 mag at 45 min after the trigger. The object coincides with a faint galaxy in the SDSS catalog which we identify as the putative host galaxy. SDSS J121621.38+201232.1 has a r'-band magnitude of 22.87 +/-0.26 mag(AB) and a photometric redshift of 0.42 +/- 0.02. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15988 SUBJECT: GRB 140318A: WHT spectroscopy DATE: 14/03/18 04:25:02 GMT FROM: Nial Tanvir at U.Leicester N. R. Tanvir (U. Leicester), T. Kruehler (ESO Chile), S. Schulze (PUC and MCSS), R. Karjalainen (ING) report: We observed the afterglow of GRB 140318A (Cenko et al. GCN 15986; Schulze et al. GCN 15987) with the WHT using the ACAM spectrograph, beginning March 18 02:06 UT, approximately 2 hours post-trigger. The wavelength range covered was from about 5000 AA to 9500 AA. In our provisional reduction, the continuum trace of the aftergow+host is well detected, and a single emission line is seen at ~7520 AA. It is most likely that this is OII 3727, given the absence of any other lines. We therefore infer a redshift of z=1.02, and tentatively identify this as the redshift of the burst. Further analysis is ongoing. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15989 SUBJECT: GRB140318A: Discovery Channel Telescope Optical Detection DATE: 14/03/18 06:55:48 GMT FROM: John Capone at UMD J. Capone (UMD), E. Troja (NASA-GSFC), V. Toy (UMD), S.B. Cenko (NASA-GSFC), A. Kutyrev (NASA-GSFC), A. Cucchiara (NASA-GSFC), S. Veilleux (UMD), and S. Gezari (UMD) report on behalf of a larger collaboration: We observed the field of GRB140318A (Cenko et al., GCN 15986) with the Large Monolithic Imager (LMI) on the recently commissioned 4.3m Discovery Channel Telescope (DCT) at Happy Jack, AZ. We started a sequence of r', i' and z' images beginning at 2014-03-18 03:32 UTC (approximately 3.5 hours after the Swift trigger). A source is clearly detected in all filters at the location of the optical afterglow (Schulze et al, GCN 15987). Using nearby point sources from SDSS for calibration, we measure preliminary magnitudes of r' = 21.6 +/- 0.2, i' = 21.14 +/- 0.06 and z' = 20.86 +/- 0.04 at an average time of ~5 hours after the GRB. These values are not corrected for Galactic extinction in the direction of the GRB. The source shows evidence of fading when compared with the NOT observation, confirming that this is the optical afterglow. Additional multi-band observations are ongoing. We thank the staff of the Discovery Channel Telescope for assistance with these observations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15990 SUBJECT: GRB 140318A: RATIR Optical and NIR Detections DATE: 14/03/18 08:32:11 GMT FROM: Owen Littlejohns at Az State U Owen Littlejohns (ASU), Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Enrico Ramirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 140318A (Cenko, et al., GCN 15986) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2014/03 18.15 to 2014/03 18.31 UTC (3.36 to 7.40 hours after the BAT trigger) obtaining a total of 0.99 hours exposure in the r and i bands and 0.60 hours exposure in the Z, Y, J, and H bands. We detect the previously reported optical counterpart (Schulze, et al. GCN 15987). In comparison with the SDSS DR9 and 2MASS, we obtain the following detections: r 21.88 +/- 0.33 i 21.37 +/- 0.18 Z 20.67 +/- 0.20 Y 20.76 +/- 0.29 J 20.60 +/- 0.21 H 20.29 +/- 0.19 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. In comparison to the observations of Schulze, et al. (GCN 15987) the measured r-band magnitude is consistent with a power-law decay with a temporal index alpha = -1.0. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15991 SUBJECT: GRB 140318A: Enhanced Swift-XRT position DATE: 14/03/18 08:51:12 GMT FROM: Phil Evans at U of Leicester M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team. Using 2346 s of XRT Photon Counting mode data and 5 UVOT images for GRB 140318A, 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 = 184.08924, +20.20902 which is equivalent to: RA (J2000): 12h 16m 21.42s Dec (J2000): +20d 12' 32.5" 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: 15992 SUBJECT: GRB 140318A: Liverpool Telescope optical observations DATE: 14/03/18 09:01:24 GMT FROM: Andrea Melandri at INAF-OAB A. Melandri (INAF-OAB), C. Guidorzi (U. Ferrara), A. Gomboc (U. Ljubljana), I. A. Steele and C. G. Mundell (LJMU), on behalf of a large collaboration report: The 2-m Liverpool Telescope robotically followed up Swift GRB 140318A (Cenko et al., GCN 15986) at 00:27:37 UT (~18.5 min after the burst trigger). We clearly detect the optical afterglow at the position reported by Schulze et al. (GCN 15987). In a coadded 6x10s SDSS-r image, we estimate the magnitude r' = 19.84 +- 0.11 at t_mid = 50.6 min since the Swift/BAT trigger time. The magnitude is calibrated against nearby SDSS stars. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15993 SUBJECT: GRB 140318A: Swift-XRT refined Analysis DATE: 14/03/18 19:35:04 GMT FROM: Phil Evans at U of Leicester C. Pagani (U. Leicester), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), P. D'Avanzo (INAF-OAB), V. Mangano (PSU), M.C. Stroh (PSU), D.N. Burrows (PSU), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester) and S.B. Cenko report on behalf of the Swift-XRT team: We have analysed 6.7 ks of XRT data for GRB 140318A (Cenko et al. GCN Circ. 15986), from 114 s to 46.2 ks after the BAT trigger. The data comprise 219 s in Windowed Timing (WT) mode (the first 9 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Goad et al. (GCN Circ. 15991). The light curve can be modelled with an initial power-law decay with an index of alpha=0.48 (+/-0.20), followed by a break at T+263 s to an alpha of 1.88 (+0.07, -0.06). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.21 (+0.12, -0.11). The best-fitting absorption column is 1.14 (+0.27, -0.25) x 10^21 cm^-2, in excess of the Galactic value of 2.6 x 10^20 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 2.9 x 10^-11 (3.9 x 10^-11) erg cm^-2 count^-1. A summary of the WT-mode spectrum is thus: Total column: 1.14 (+0.27, -0.25) x 10^21 cm^-2 Galactic foreground: 2.6 x 10^20 cm^-2 Excess significance: 5.8 sigma Photon index: 2.21 (+0.12, -0.11) If the light curve continues to decay with a power-law decay index of 1.88, the count rate at T+24 hours will be 2.1 x 10^-4 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 6.2 x 10^-15 (8.3 x 10^-15) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00592204. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15996 SUBJECT: GRB 140318A: Swift-BAT refined analysis DATE: 14/03/18 23:58:07 GMT FROM: Amy Lien at GSFC C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), S. B. Cenko (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/UMBC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (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 140318A (trigger #592204) (Cenko, et al., GCN Circ. 15986). The BAT ground-calculated position is RA, Dec = 184.049, 20.225 deg which is RA(J2000) = 12h 16m 11.8s Dec(J2000) = +20d 13' 30.8" with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 49%. The mask-weighted light curve shows a main single pulse starts at ~T+2 s and ends at ~T+12 s, with some weak extented emissions starting before the main pulse at ~T-20 s and extended after the pulse to ~T+50 s. T90 (15-350 keV) is 8.43 +- 1.27 sec (estimated error including systematics). The time-averaged spectrum from T+2.24 to T+11.68 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.35 +- 0.28. The fluence in the 15-150 keV band is 2.9 +- 0.5 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+5.48 sec in the 15-150 keV band is 0.5 +- 0.2 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/592204/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15997 SUBJECT: GRB 140318A: Swift/UVOT Upper Limits DATE: 14/03/19 14:07:38 GMT FROM: Mike Siegel at PSU/Swift MOC B. Porterfield (PSU) and Cenko (GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 140318A 132 s after the BAT trigger (Cenko et al., GCN Circ. 15986). No optical afterglow consistent with the XRT position (Cenko et al. GCN Circ. 15986) or NOT position (Schulze et al., GCN Circ 15987) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 132 282 147 >21.2 white 132 5340 541 >21.9 v 4115 5750 393 >19.6 b 3499 5135 393 >20.9 u 4730 4930 197 >20.1 w1 4525 6063 298 >20.5 m2 4320 5955 393 >21.2 w2 3910 5546 393 >20.7 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.02 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15998 SUBJECT: GRB 140318A: Mondy optical limit DATE: 14/03/19 15:00:05 GMT FROM: Alexei Pozanenko at IKI, Moscow A.Volnova (IKI), E. Klunko (ISTP), I. Korobtsev (ISTP), M. Eselevich (ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 140318A (Cenko et al., GCN 15986) with AZT-33IK telescope of Mondy observatory starting on Mar. 18 (UT) 13:18:36. Within enhanced Swift-XRT eror circle (Goad et al., GCN 15991) we do not detect the optical afterglow (Schulze et al., GCN 15987). Details of preliminary photometry is following: date UT start t-T0 Exp. Filter UpperLimit (3sigma) (mid, days) (s) 2014-03-18 13:18:36 0.59896 58x120 R 21.1 The photometry is based on reference star SDSS-DR9, (R mag, transformation by Lupton 2005): N SDSS_id R(Lupton) err J121613.64+200907.3 16.984 0.008 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15999 SUBJECT: GRB 140318A: Continued RATIR Optical and NIR Observations DATE: 14/03/19 21:38:45 GMT FROM: Owen Littlejohns at Az State U Owen Littlejohns (ASU), Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Enrico Ramirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 140318A (Cenko, et al., GCN 15986) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2014/03 19.13 to 2014/03 19.50 UTC (26.91 to 35.94 hours after the BAT trigger), obtaining a total of 4.88 hours exposure in the r and i bands and 2.46 hours exposure in the Z and Y bands. We continue to detect the previously reported optical counterpart (Littlejohns, et al., GCN 15990; Schulze, et al., GCN 15987). In comparison with the SDSS DR9 and 2MASS, we obtain the following detections: r 22.52 +/- 0.11 i 22.05 +/- 0.09 Z 21.58 +/- 0.12 Y 21.51 +/- 0.16 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. Fading of the source is detected for all of the four bands measured in both epochs of RATIR observations. We note that the temporal decay index between these two epochs appears to be shallower than that reported in Littlejohns, et al. (GCN 15990), with -0.5 < alpha < -0.3 for all four bands. This can be interpretted as the magnitude approaching that of the underlying SDSS galaxy reported in Schulze, et al. (GCN 15987). We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir.