GRB160408A

This page lists all entries on GRB160408A in GRBweb

Summary Fermi GBM IPN Swift GCN 19260 GCN 19261 GCN 19262 GCN 19263 GCN 19265 GCN 19266 GCN 19267 GCN 19268 GCN 19269 GCN 19270 GCN 19294 GCN 19297 GCN 19508

Summary table
Variable Value Source
GRB_name_Fermi GRB160408268
T0 6:25:43 UTC GCN_circulars,Swift Det
ra 122.6246° Swift
decl 71.1283° Swift
pos_error 2.07e-04° Swift
T90 1.056 s Fermi_GBM
T90_error 0.604 s Fermi_GBM
T90_start 6:25:43.313 UTC Fermi_GBM
fluence 6.98e-07 erg/cm² Fermi_GBM
fluence_error 2.80e-08 erg/cm² Fermi_GBM
T100 1.369 s
GBM_located False
mjd 57486.267858796295 GCN_circulars,Swift Det
Fermi GBM table
GRB_name_Fermi GRB160408268
trigger_name bn160408268
ra 122.6229°
decl 71.1283°
pos_error 4.18e+00°
datum 2016-04-08
t_trigger 6:25:43.857 UTC
T90 1.056 s
T90_error 0.604 s
T90_start 6:25:43.313 UTC
fluence 6.98e-07 erg/cm²
fluence_error 2.80e-08 erg/cm²
flux_1024 4.05e+00 erg/cm²/s
flux_1024_error 2.55e-01 erg/cm²/s
flux_1024_time -5.76e-01 erg/cm²/s
flux_64 1.27e+01 erg/cm²/s
flux_64_error 1.33e+00 erg/cm²/s
IPN table
GRB_name GRB160408A
ra 122.5583°
decl 71.1333°
pos_error 5.00e-02°
Swift table
GRB_name GRB160408A
t_trigger 6:25:43 UTC
ra 122.6246°
decl 71.1283°
pos_error 2.07e-04°
T90 0.32 s
fluence 1.60e-07 erg/cm²
GCN 19260 table
GRB_name GRB160408A
GCN_number 19260
Detection_method Swift Det
t_trigger 6:25:43 UTC
ra 122.5570°
decl 71.1400°
Circular_text TITLE: GCN CIRCULAR NUMBER: 19260 SUBJECT: GRB 160408A: Swift detection of a short burst DATE: 16/04/08 06:39:08 GMT FROM: David Palmer at LANL P.A. Evans (U Leicester), S. D. Barthelmy (GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the Swift Team: At 06:25:43 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 160408A (trigger=682059). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 122.557, +71.140, which is RA(J2000) = 08h 10m 14s Dec(J2000) = +71d 08' 25" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single spike with a duration of about 0.5 sec. The peak count rate was ~5000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 06:27:18.5 UT, 94.8 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 122.6235, 71.1284 which is equivalent to: RA(J2000) = 08h 10m 29.64s Dec(J2000) = +71d 07' 42.3" with an uncertainty of 2.2 arcseconds (radius, 90% containment). This location is 87 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 in excess of the Galactic value (4.18 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 3.9 (+3.04/-2.61) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 98 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers none of the XRT error circle. 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 0.03. Burst Advocate for this burst is P.A. Evans (pae9 AT star.le.ac.uk). 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.)
GCN 19261 table
GRB_name GRB160408A
GCN_number 19261
Detection_method Swift-XRT Det
ra 122.6247°
decl 71.1283°
Circular_text TITLE: GCN CIRCULAR NUMBER: 19261 SUBJECT: GRB 160408A: Enhanced Swift-XRT position DATE: 16/04/08 09:58:51 GMT FROM: Phil Evans at U of Leicester J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team. Using 1293 s of XRT Photon Counting mode data and 2 UVOT images for GRB 160408A, 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 = 122.62470, +71.12831 which is equivalent to: RA (J2000): 08h 10m 29.93s Dec (J2000): +71d 07' 41.9" 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.
GCN 19262 table
GRB_name GRB160408A
GCN_number 19262
Detection_method Optical
ra 122.6242°
Circular_text TITLE: GCN CIRCULAR NUMBER: 19262 SUBJECT: GRB 160408A: Gemini optical observations DATE: 16/04/08 10:45:28 GMT FROM: Andrew Levan at U.of Leicester A.J. Levan (U. Warwick) and N.R. Tanvir (U. Leicester) report for a larger collaboration: “We observed the location of the short GRB 160408A (Evans et al. GCN 19260) with Gemini-North and GMOS. Observations were taken in the r-band, starting at 07:23 UT, approximately 58 minutes after the burst. Several objects are present in the field close to the refined XRT position (Osborne et al. GCN 19261). The closest objects are a compact source (A) and a more extended galaxy (B). The locations of these sources are: Source A: RA(J2000) 08h 10m 29.81s DEC(J2000) 71d 07’ 43.7” Source B: RA(J2000) 08h 10m 29.32s DEC(J2000) 71d 07’ 40.5” with an uncertainty of approximately 0.3” in each co-ordinate. Conditions were not photometric at the time of the observations, but comparison with USNO-B1 sources in the field of view suggests that source A has a magnitude of r~24.5, source B is approximately a magnitude brighter. We thank the Gemini staff for the rapid execution of these observations.“
GCN 19263 table
GRB_name GRB160408A
GCN_number 19263
Detection_method Swift-BAT Det
ra 122.5610°
decl 71.1280°
Circular_text TITLE: GCN CIRCULAR NUMBER: 19263 SUBJECT: GRB 160408A: Swift-BAT refined analysis DATE: 16/04/08 13:13:33 GMT FROM: Scott Barthelmy at NASA/GSFC D. M. Palmer (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), P.A. Evans (U Leicester), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-120 to T+302 sec from the recent telemetry downlinks, we report further analysis of BAT GRB 160408A (trigger #682059) (Evans, et al., GCN Circ. 19260). The BAT ground-calculated position is RA, Dec = 122.561, 71.128 deg, which is RA(J2000) = 08h 10m 14.6s Dec(J2000) = +71d 07' 40.0" with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 33%. The mask-weighted light curve starts at ~T0, peaks at ~T+0.1 sec, and ends at ~T+0.4 sec. T90 (15-350 keV) is 0.32 +- 0.04 sec (estimated error including systematics). The time-averaged spectrum from T+0.02 to T+0.37 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 0.85 +- 0.25. The fluence in the 15-150 keV band is 1.6 +- 0.2 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-0.30 sec in the 15-150 keV band is 2.1 +- 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/682059/BA/ We note that this burst was detected by Fermi-GBM, CALET-GBM, Swift-BAT, and INTEGRAL-SPIACS.
GCN 19265 table
GRB_name GRB160408A
GCN_number 19265
Detection_method Fermi GBM Det
t_trigger 6:25:43.860 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 19265 SUBJECT: GRB 160408A: Fermi GBM detection DATE: 16/04/08 15:23:19 GMT FROM: Oliver Roberts at UCD/Fermi O.J. Roberts (UCD) reports on behalf of the Fermi GBM Team: "At 06:25:43.86 UT on the 8th of April 2016, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 160408A (trigger 481789547 / 160408268), which was also detected by Swift (Evans et al. 2008, GCN 19620). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time using the Swift XRT position is about 7 degrees. The GBM light curve consists of two bright, short emission episodes, with a duration (T90) of about 0.9 s (50-300 keV). The time-averaged spectrum from T0-0.064 s to T0+0.384 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.76 +/- 0.10 and the cutoff energy, parameterized as Epeak, is 914 +/- 184 keV. The event fluence (10-1000 keV) in this time interval is (1.25 +/- 0.08)E-06 erg/cm^2. The 64 ms peak photon flux measured starting from T0+0 s in the 10-1000 keV band, is 12.4 +/- 1.4 ph/s/cm^2. A Band function fits the spectrum equally well, with Epeak = 765 +/- 198 keV, alpha = -0.70 +/- 0.12, and beta = -2.27 +/- 0.41. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN 19266 table
GRB_name GRB160408A
GCN_number 19266
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 19266 SUBJECT: GRB 160408A: Swift-XRT refined Analysis DATE: 16/04/08 18:14:24 GMT FROM: Phil Evans at U of Leicester J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), C. Pagani (U. Leicester), A. D'Ai (INAF-IASFPA), A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), D.N. Burrows (PSU) and P.A. Evans report on behalf of the Swift-XRT team: We have analysed 6.2 ks of XRT data for GRB 160408A (Evans et al. GCN Circ. 19260), from 103 s to 23.4 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN Circ. 19261). The light curve can be modelled with a power-law decay with a decay index of alpha=1.3 (+/-0.3). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.1 (+/-0.4). The best-fitting absorption column is 1.6 (+1.4, -1.1) x 10^21 cm^-2, in excess of the Galactic value of 4.2 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 3.4 x 10^-11 (4.6 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.6 (+1.4, -1.1) x 10^21 cm^-2 Galactic foreground: 4.2 x 10^20 cm^-2 Excess significance: 1.9 sigma Photon index: 2.1 (+/-0.4) If the light curve continues to decay with a power-law decay index of 1.3, the count rate at T+24 hours will be 8.4 x 10^-5 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.8 x 10^-15 (3.8 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/00682059. This circular is an official product of the Swift-XRT team.
GCN 19267 table
GRB_name GRB160408A
GCN_number 19267
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 19267 SUBJECT: GRB 160408A: Swift/UVOT Upper Limits DATE: 16/04/08 20:15:45 GMT FROM: Mike Siegel at PSU/Swift MOC M. H. Siegel (PSU) and P. A. Evans (U Leicester) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 160408A 98 s after the BAT trigger (Evans et al., GCN Circ. 19260). No optical afterglow consistent with the XRT position (Osborne et al. GCN Circ. 19261) or the possible optical counterparts (Levan et al., GCN Circ. 19262) 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 98 248 147 >21.0 u_FC 311 561 246 >19.7 white 98 1365 373 >21.8 v 641 1414 97 >19.4 b 566 1340 78 >19.6 u 311 1316 304 >19.9 w1 691 1291 58 >19.5 m2 838 1092 39 >18.8 w2 617 1390 97 >19.9 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998).
GCN 19268 table
GRB_name GRB160408A
GCN_number 19268
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 19268 SUBJECT: GRB 160408A: TLS Tautenburg observations DATE: 16/04/09 09:34:20 GMT FROM: Sebastian Schmidl at TLS Tautenburg J. I. Avalos (University of Leipzig), N. P. Plaza (Universidad Autonoma de Madrid), M. Blunck (University of Leipzig), L. Lalounta (University of Patras), E. Komucyeya (Mbarara University), S. Schmidl, S. Klose, D. A. Kann, A. Nicuesa Guelbenzu, and F. Ludwig (all TLS Tautenburg) report: We observed the field of the short GRB 160408A (Evans et al., GCN 19260) with the Tautenburg 1.34-m Schmidt telescope at as mid-time of about 15.3 hrs after the GRB trigger, at a mean airmass of 1.2. We obtained 10 x 300 sec exposures in the Ic band. Inside the 1".9 enhanced XRT error circle (Osborne et al.,GCN 19261), we do not detect the possible optical counterparts reported by Levan et al. (GCN Circ. 19262). We estimate a preliminary upper limit of Ic > 21.3 mag, calibrated against USNO-B1 field stars. These observations were performed as part of the Tautenburg Observing School at the Thueringer Landessternwarte. [GCN OPS REPORT(14apr16): Per author's request, the institutional affiliations of the authors was corrected, and the last sentence was added.]
GCN 19269 table
GRB_name GRB160408A
GCN_number 19269
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 19269 SUBJECT: GRB 160408A: Gemini afterglow confirmation DATE: 16/04/09 15:04:49 GMT FROM: Andrew Levan at U.of Leicester A.J. Levan (U. Warwick), N.R. Tanvir (U. Leicester), A. Cucchiara (GSFC/STScI), W. Fong (Arizona), D. Perley (DARK/NBI) report for a larger collaboration: “We obtained a second epoch of Gemini-North observations of the short GRB 160408A (Evans et al. GCN 19260, Palmer et al. GCN 19263) on 9 April 2016, approximately 22 hours after our previous observations. Although the images are somewhat shallower than the first epoch, the previously identified source A (Levan & Tanvir GCN 19262) has clearly faded by at least a magnitude between the two epochs, and is not detected in our new imaging. This confirms it as the optical afterglow of GRB 160408A.”
GCN 19270 table
GRB_name GRB160408A
GCN_number 19270
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 19270 SUBJECT: GRB 160408A: GMG observation limit DATE: 16/04/10 02:50:48 GMT FROM: Jirong Mao at Yunnan Obs W.-M. Yi, J. Mao and J.-M. Bai (YNAO) report: We observed the field of GRB 160408A (Evans et al., GCN 19260) with the 2.4-meter optical telescope at Gao-Mei-Gu (GMG) station of Yunnan Observatories. Observations began from 15:10:26 UT, Apr. 8th, 2016, about 9 hours after the trigger. We did not detect any source at the afterglow position (Levan et al. GCN 19269) down to a limit of R~23.3 mag.
GCN 19294 table
GRB_name GRB160408A
GCN_number 19294
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 19294 SUBJECT: GRB 160408A: 6.0 GHz VLA upper limit DATE: 16/04/11 19:13:39 GMT FROM: Wen-fai Fong at U of Arizona W. Fong (University of Arizona) reports: "We observed the field of the short-duration GRB 160408A (Evans et al., GCN 19260) with the Karl G. Jansky Very Large Array (VLA) beginning on 2016 Apr 8.889 UT (14.91 hr post-burst) at a mean frequency of 6.0 GHz. In 1 hour of observations, we do not detect any radio source within or around the enhanced XRT position (Osborne et al., GCN 19261) or the optical afterglow position (Levan et al., GCNs 19262, 19269) to a 3-sigma limit of 21.5 microJy. We therefore place a 3-sigma limit of 21.5 microJy on the radio afterglow of GRB 160408A at 14.91 hr after the burst. We thank the VLA staff for quickly executing these observations."
GCN 19297 table
GRB_name GRB160408A
GCN_number 19297
Detection_method CALET
Circular_text TITLE: GCN CIRCULAR NUMBER: 19297 SUBJECT: GRB 160408A: CALET Gamma-Ray Burst Monitor detection DATE: 16/04/12 02:48:31 GMT FROM: Takanori Sakamoto at AGU W. Ishizaki (ICRR), A. Yoshida, T. Sakamoto, Y. Kawakubo, M. Moriyama, Y. Yamada (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), I. Takahashi (IPMU), Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena) and the CALET collaboration: The short-duration GRB 160408A (Swift, Evans et al. GCN Circ. 19260; Fermi-GBM, Roberts et al. GCN Circ. 19265; INTEGRAL-ACS, Trigger #7441) triggered the CALET Gamma-Ray Burst Monitor (CGBM) at 6:25:37.4 on 8 April 2016. The burst signal was detected by all CGBM instruments. The light curve of the SGM shows a single peak. The emission starts at T0+6.4 sec, peaks at T0+6.5 sec and ends at T0+7.1 sec. The T90 duration measured by the SGM data is 0.38 +- 0.18 sec (40-1000 keV). The CGBM data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University.
GCN 19508 table
GRB_name GRB160408A
GCN_number 19508
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 19508 SUBJECT: GRB 160408A: 15 GHz upper limits from AMI DATE: 16/06/08 15:12:47 GMT FROM: Kunal Mooley at Oxford U K. P. Mooley, T. D. Staley, R. P. Fender (Oxford), G. E. Anderson (Curtin), T. Cantwell (Manchester), C. Rumsey, D. Titterington, S. Carey, J. Hickish, Y. C. Perrott, N. Razavi-Ghods, P. Scott (Cambridge), K. Grainge, A. Scaife (Manchester) The AMI Large Array robotically triggered on the Swift alert for GRB 160408A (Evans et al., GCN 19260) as part of the 4pisky program, and subsequent follow up observations were obtained up to 10 days post-burst. Our observations at 15 GHz on 2016 Apr 08.61, Apr 09.77, Apr 13.87, Apr 15.74, and Apr 19.78 (UT) do not reveal any radio source at the XRT location (Osborne et al., GCN 19261), with 3sigma upper limits of 117 uJy, 144 uJy, 102 uJy, 204 uJy, and 145 uJy respectively. We thank the AMI staff for scheduling these observations. The AMI-GRB database is a log of all GRB follow up observations with the AMI, and is available at http://4pisky.org/ami-grb/.