//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16098 SUBJECT: Swift Trigger 595616: a possible GRB DATE: 14/04/13 00:29:27 GMT FROM: Valerio D'Elia at ASDC V. D'Elia (ASDC), S. T. Holland (STScI), L. Izzo (URoma/ICRA), F. E. Marshall (NASA/GSFC) and B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team: At 00:09:40 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 140413A (trigger=595616). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 65.449, -51.205 which is RA(J2000) = 04h 21m 48s Dec(J2000) = -51d 12' 17" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). This is an image trigger and we cannot say much about the light curve. However, since it is 12.5 sigma detection at 64 sec exposure in the image domain, it is likely to be real. Due to an observing constraint, Swift will not slew until T0+33.6 minutes. There will be no XRT or UVOT data until this time. Burst Advocate for this burst is V. D'Elia (delia AT asdc.asi.it). 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: 16099 SUBJECT: GRB 140413A: GROND afterglow candidate DATE: 14/04/13 01:37:26 GMT FROM: Ana Nicuesa at TLS Tautenburg K. Varela, C. Delvaux (both MPE Garching), A. Nicuesa Guelbenzu (TLS Tautenburg), and J. Greiner (MPE Garching) report on behalf of the GROND team: We observed the field of GRB 140413A (Swift trigger 595616; D'Elia et al., GCN #16098) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at La Silla Observatory (Chile). Observations started at 00:13 UT on 13 April 2014, less than 5 min after the GRB trigger, and are continuing. They are performed at a mean airmass of 1.9 and a mean seeing of 0.9". We find a single point source within the 5.8" Swift/XRT error circle at coordinates RA(J2000) = 04:21:49.23 Dec(J2000) = -51:10:58.0. At a midtime of 00:17 UT we measure the following preliminary AB magnitudes: r' = 20.2 +/- 0.1, i' = 19.6 +/- 0.1, z' = 19.3 +/- 0.1. The source is also visible in g. At present we cannot decide if the source is fading. Data processing is still ongoing, observations are continuing. Given magnitudes 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)=0.02 mag in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16101 SUBJECT: GRB 140413A: Swift-XRT observations DATE: 14/04/13 08:44:37 GMT FROM: Luca Izzo at ICRA V. D'Elia (ASDC) and L. Izzo (URoma/ICRA) report for the Swift/XRT team: The XRT began observing the field of GRB 140413A at 00:46:31.37 UT, 2211.2 seconds after the BAT trigger. We find an uncatalogued X-ray source located at RA, Dec 65.4544, -51.1831 which is equivalent to:  RA(J2000)  =+04h 21m 49.0s  Dec(J2000) =-51d 10' 59.1" with an uncertainty of 4.7 arcseconds (radius, 90% containment). This location is 80 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16102 SUBJECT: GRB 140413A: TAROT La Silla observatory optical observations DATE: 14/04/13 10:43:21 GMT FROM: Alain Klotz at IRAP-CNRS-OMP Klotz A., Turpin D. (IRAP-CNRS-OMP), Boer M., Gendre B., Siellez K., Dereli H., Bardho O. (UNS-CNRS-OCA), Atteia J.L. (IRAP-CNRS-OMP) report: We imaged the field of GRB 140413A detected by SWIFT (trigger 595616) with the TAROT robotic telescope (D=25cm) located at the European Southern Observatory, La Silla observatory, Chile. The observations started 92.3s after the GRB trigger (16.4s after the notice) probably during the end of the prompt gamma emission regarding the BAT light curve. The elevation of the field decreased from 36 degrees above horizon and weather conditions were good. The first image is trailed with a duration of 60.0s (see the description in Klotz et al., 2006, A&A 451, L39). We do not detect the GROND OT candidate (Varela et al. GCNC 16099) with a limiting magnitude of: t0+92.3s to t0+152.3s : Rlim = 17.0 The second image is 30.0s exposure in tracking mode: t0+165.6s to t0+195.6s : Rlim = 17.6 We co-added series of exposures: t0+165.6s to t0+457.5s : Rlim = 19.3 t0+468.3s to t0+ 1362s : Rlim = 19.3 Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16105 SUBJECT: GRB 140413A: Swift-BAT refined analysis DATE: 14/04/13 16:31:11 GMT FROM: Scott Barthelmy at NASA/GSFC S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), V. D'Elia (ASDC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/UMBC), C. B. Markwardt (GSFC), 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-239 to T+963 sec from recent telemetry downlinks, we report further analysis of BAT GRB 140413A (trigger #595616) (D'Elia, et al., GCN Circ. 16098). The BAT ground-calculated position is RA, Dec = 65.439, -51.188 deg, which is RA(J2000) = 04h 21m 45.4s Dec(J2000) = -51d 11' 15.1" with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 12%. The mask-weighted light curve shows a slow rise starting at ~T-65 sec, peaking at ~T+80 sec, and a faster decay out to ~T+115 sec. T90 (15-350 keV) is 139.6 +- 12.6 sec (estimated error including systematics). The time-averaged spectrum from T-52.0 to T+120.4 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.49 +- 0.08. The fluence in the 15-150 keV band is 9.4 +- 0.5 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+77.05 sec in the 15-150 keV band is 2.3 +- 0.5 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/595616/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16106 SUBJECT: GRB 140413A: Swift-XRT refined Analysis DATE: 14/04/14 11:39:30 GMT FROM: Luca Izzo at ICRA L. Izzo (URoma/ICRA) and V. D'Elia (ASDC) report on behalf of the Swift-XRT team: We have analysed 13 ks of XRT data for GRB 140413A, from 2.2 ks to 83.3 ks after the BAT trigger. The data comprise 2.1 ks in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. Using 3951 s of PC mode data and 4 UVOT images, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 65.45475, -51.18310 which is equivalent to: RA (J2000): 04h 21m 49.14s Dec(J2000): -51d 10' 59.2" with an uncertainty of 1.6 arcsec (radius, 90% confidence). The late-time light curve (from T0+38.1 ks) can be modelled with a power-law decay with a decay index of alpha=1.7 (+/-0.4). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.989 (+0.025, -0.024). The best-fitting absorption column is 4.04 (+/-0.13) x 10^21 cm^-2, in excess of the Galactic value of 1.4 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.9 x 10^-11 (6.0 x 10^-11) erg cm^-2 count^-1. A summary of the WT-mode spectrum is thus: Total column: 4.04 (+/-0.13) x 10^21 cm^-2 Galactic foreground: 1.4 x 10^20 cm^-2 Excess significance: 49.9 sigma Photon index: 1.989 (+0.025, -0.024) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00595616. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16107 SUBJECT: Konus-Wind observation of GRB 140413A DATE: 14/04/14 12:09:24 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, and T. Cline on behalf of the Konus-Wind team, report: The long GRB 140413A (Swift-BAT trigger #595616: D'Elia et al., GCN 16098; T0(BAT)=00:09:40 UT) was detected by Konus-Wind in the waiting mode. The light curve shows a broad emission pulse which started ~65 s before the BAT trigger, peaked at ~T0(BAT)+80 s, and lasted till ~T0(BAT)+120 s. A possible soft precursor is seen at ~T0(BAT)-950 s in the softest KW energy band, however its association with GRB 140413A is not confirmed yet. The K-W light curve of this burst is available at http://www.ioffe.rssi.ru/LEA/GRBs/GRB140413A/ As observed by Konus-Wind, the burst had a fluence of (2.9 ± 0.3)x10^-5 erg/cm2 and a 2.944-s peak energy flux, measured from ~T0(BAT)+80 s, of (5.2 ± 0.5)x10^-7 erg/cm2 (both in the 20 - 10000 keV energy range). Modeling the KW 3-channel time-integrated spectrum (from T0(BAT)-60 s to T0(BAT)+121 s) by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) yields alpha = -1.37 ± 0.11, and Ep = 228 ± 42 keV. All the quoted errors are estimated at the 1 sigma confidence level. All the presented results are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16109 SUBJECT: GRB 140413A: Swift/UVOT Observations of the Optical Afterglow DATE: 14/04/14 12:50:51 GMT FROM: Stephen Holland at STScI S. T. Holland (STScI) and V. D'Elia (ASDC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 140413A 2221 s after the BAT trigger (D'Elia et al., 2014, GCNC 16098). The preliminary UVOT position is RA (J2000) 04:21:49.23 = 65.45512 (deg) Dec (J2000) -51:10:58.0 = -51.18278 (deg) with an estimated uncertainty of 1.79 arcsec (radius, 90% confidence, statistical + systematic). We detect the optical afterglow at the position reported by Varela et al. (2014, GCNC 16099). Preliminary UVOT photometry and 3-sigma upper limits are presented below. ---------------------------------------------------------------- Filter TSTART TSTOP Exposure Mag Err Sigma ---------------------------------------------------------------- v 2377 4303 375 >19.7 b 2476 3747 235 >21.0 u 2451 3542 236 >19.9 uvw1 2427 3336 236 >19.8 uvm2 2931 3131 197 >19.5 uvw2 3957 4157 197 >20.1 white 2221 2370 147 >20.3 3752 3951 197 21.10 0.29 3.8 ---------------------------------------------------------------- The quoted magnitudes and upper limits have not been corrected for the Galactic extinction along the line of sight to this burst of E_{B-V} = 0.01 mag (Schlafly et al. 2011, ApJS, 737, 103). The photometry is in the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16172 SUBJECT: GRB 140413A: GROND Afterglow Confirmation DATE: 14/04/25 12:56:00 GMT FROM: Alexander Kann at TLS Tautenburg C. Delvaux (MPE Garching), D. A. Kann, S. Schmidl (both TLS Tautenburg), and J. Greiner (MPE Garching) report on behalf of the GROND team: We re-observed the field of GRB 140413A (Swift trigger 595616; D'Elia et al., GCN # 16098) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at La Silla Observatory (Chile). Further epochs were obtained at 1, 2, 3 and 5 days after the trigger. The source detected in the XRT error circle in early observations (Varela et al., GCN # 16099) has faded by about 3 magnitudes in the r' band, confirming that it is the afterglow of GRB 140413A. In the later epochs we obtain detections in g'r'i'z'J at a constant level, possibly the host galaxy of the GRB. If it is the host galaxy, this may be indicative of a relatively low redshift.