GRB170318B

This page lists all entries on GRB170318B in GRBweb

Summary Fermi GBM IPN Swift GCN 20908 GCN 20909 GCN 20910 GCN 20913 GCN 20918 GCN 20919 GCN 20921 GCN 20923 GCN 20957

Summary table
Variable Value Source
GRB_name_Fermi GRB170318644
T0 15:27:50.976 UTC Fermi_GBM
ra 284.3061° Swift
decl 6.2992° Swift
pos_error 2.33e-04° Swift
T90 4.096 s Fermi_GBM
T90_error 2.319 s Fermi_GBM
T90_start 15:27:50.976 UTC Fermi_GBM
fluence 5.08e-07 erg/cm² Fermi_GBM
fluence_error 5.16e-08 erg/cm² Fermi_GBM
T100 161.024 s
GBM_located False
mjd 57830.64434 Fermi_GBM
Fermi GBM table
GRB_name_Fermi GRB170318644
trigger_name bn170318644
ra 284.3058°
decl 6.2986°
pos_error 8.92e+00°
datum 2017-03-18
t_trigger 15:27:53.088 UTC
T90 4.096 s
T90_error 2.319 s
T90_start 15:27:50.976 UTC
fluence 5.08e-07 erg/cm²
fluence_error 5.16e-08 erg/cm²
flux_1024 1.86e+00 erg/cm²/s
flux_1024_error 2.34e-01 erg/cm²/s
flux_1024_time -7.68e-01 erg/cm²/s
flux_64 3.79e+00 erg/cm²/s
flux_64_error 1.06e+00 erg/cm²/s
IPN table
GRB_name GRB170318B
ra 284.2792°
decl 6.2667°
pos_error 5.00e-02°
Swift table
GRB_name GRB170318B
t_trigger 15:27:52 UTC
ra 284.3061°
decl 6.2992°
pos_error 2.33e-04°
T90 160.0 s
fluence 5.50e-07 erg/cm²
GCN 20908 table
GRB_name GRB170318B
GCN_number 20908
Detection_method Swift Det
t_trigger 15:27:52 UTC
ra 284.2790°
decl 6.2690°
Circular_text TITLE: GCN CIRCULAR NUMBER: 20908 SUBJECT: GRB 170318B: Swift detection of a burst DATE: 17/03/18 15:39:36 GMT FROM: Scott Barthelmy at NASA/GSFC A. Cholden-Brown (PSU), S. D. Barthelmy (GSFC), D. N. Burrows (PSU), J. A. Kennea (PSU), H. A. Krimm (CRESST/NSF/USRA), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the Swift Team: At 15:27:52 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 170318B (trigger=743086). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 284.279, +6.269, which is RA(J2000) = 18h 57m 07s Dec(J2000) = +06d 16' 10" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single peak with a duration of about 3 sec. The peak count rate was ~1900 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 15:29:06.3 UT, 73.7 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 284.30606, 6.29833 which is equivalent to: RA(J2000) = 18h 57m 13.45s Dec(J2000) = +06d 17' 54.0" with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 141 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. A power-law fit to a spectrum formed from promptly downlinked event data does not constrain the column density. The initial flux in the 2.5 s image was 5.39e-10 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 84 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 100% of the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 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 large, but uncertain extinction expected. Burst Advocate for this burst is A. Cholden-Brown (aaronb AT swift.psu.edu). 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 20909 table
GRB_name GRB170318B
GCN_number 20909
Detection_method Swift-XRT Other
ra 284.3062°
decl 6.2994°
Circular_text TITLE: GCN CIRCULAR NUMBER: 20909 SUBJECT: GRB 170318B: Prompt enhanced Swift-XRT position DATE: 17/03/18 16:17:21 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Using promptly downlinked XRT event data for GRB 170318B, we find an enhanced XRT position of the afterglow: RA, Dec: 284.3062, 6.2994 which is equivalent to: RA (J2000) = 18 57 13.49 Dec (J2000) = +06 17 57.9 with an uncertainty of 2.1 arcseconds (radius, 90% confidence). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/743086. Position enhancement is is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular is an official product of the Swift-XRT team.
GCN 20910 table
GRB_name GRB170318B
GCN_number 20910
Detection_method Swift-XRT Det
ra 284.3061°
decl 6.2992°
Circular_text TITLE: GCN CIRCULAR NUMBER: 20910 SUBJECT: GRB 170318B: Enhanced Swift-XRT position DATE: 17/03/18 17:06:50 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 839 s of XRT Photon Counting mode data and 1 UVOT images for GRB 170318B, 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 = 284.30611, +6.29924 which is equivalent to: RA (J2000): 18h 57m 13.47s Dec (J2000): +06d 17' 57.3" 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 20913 table
GRB_name GRB170318B
GCN_number 20913
Detection_method Fermi GBM Det
t_trigger 15:27:53.090 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 20913 SUBJECT: GRB 170318B: Fermi GBM observation DATE: 17/03/18 20:28:15 GMT FROM: Peter Veres at UAH P. Veres and C. Meegan (both UAH) report on behalf of the Fermi GBM Team: "At 15:27:53.09 UT on 18 March 2018, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 170318B (trigger 511543678 / 170318644). which was also detected by the Swift/BAT (Cholden-Brown et al. 2008, GCN 20908) The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time is 93 degrees. The GBM light curve shows a single peak with a duration (T90) of about 4 s (50-300 keV). The time-averaged spectrum from T0-3.3 s to T0+1.8 s is adequately fit by a simple power law function with index -1.40 +/- 0.10. The event fluence (10-1000 keV) in this time interval is (8.0 +/- 1.4)E-7 erg/cm^2. The 1-sec peak photon flux measured starting from T0-0.8 s in the 10-1000 keV band is 1.9 +/- 0.2 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN 20918 table
GRB_name GRB170318B
GCN_number 20918
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 20918 SUBJECT: GRB 170318B: Swift-XRT refined Analysis DATE: 17/03/19 05:09:13 GMT FROM: Phil Evans at U of Leicester J.A. Kennea (PSU), P.A. Evans (U. Leicester), S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU) and report on behalf of the Swift-XRT team: report on behalf of the Swift-XRT team: We have analysed 7.2 ks of XRT data for GRB 170318B, from 64 s to 41.1 ks after the BAT trigger. The data comprise 95 s in Windowed Timing (WT) mode (the first 8 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The light curve can be modelled with an initial rise, with a power-law index of alpha=-0.5 (+0.4, -0.5), followed by a break at T+134 s to an alpha of 2.96 (+0.16, -0.15). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.6 (+/-0.4). The best-fitting absorption column is 6.4 (+1.7, -1.4) x 10^22 cm^-2, in excess of the Galactic value of 1.4 x 10^22 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 2.3 (+/-0.6) and a best-fitting absorption column of 6.2 (+2.1, -1.7) x 10^22 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 8.0 x 10^-11 (3.5 x 10^-10) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 6.2 (+2.1, -1.7) x 10^22 cm^-2 Galactic foreground: 1.4 x 10^22 cm^-2 Excess significance: 4.6 sigma Photon index: 2.3 (+/-0.6) If the light curve continues to decay with a power-law decay index of 2.96, the count rate at T+24 hours will be 4.5 x 10^-8 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.6 x 10^-18 (1.6 x 10^-17) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00743086. This circular is an official product of the Swift-XRT team.
GCN 20919 table
GRB_name GRB170318B
GCN_number 20919
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 20919 SUBJECT: GRB 170318B: Swift/UVOT Upper Limits DATE: 17/03/19 08:56:36 GMT FROM: Alice Breeveld at MSSL-UCL A. A. Breeveld (UCL-MSSL) and A. Cholden-Brown (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 170318B 84 s after the BAT trigger (Cholden-Brown et al., GCN Circ. 20908). No optical afterglow consistent with the XRT position (Goad et al. GCN Circ. 20910) 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 84 234 147 >20.4 u_FC 296 546 246 >19.8 white 84 6145 530 >21.0 v 626 6557 432 >19.4 b 552 5940 236 >20.0 u 296 7172 659 >20.2 w1 675 6967 432 >19.9 m2 5123 5323 197 >19.3 w2 601 6352 216 >19.6 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 4.51 in the direction of the burst (Schlegel et al. 1998).
GCN 20921 table
GRB_name GRB170318B
GCN_number 20921
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 20921 SUBJECT: GRB 170318B: RATIR Optical and NIR Observations DATE: 17/03/19 17:09:31 GMT FROM: Alan M. Watson at Instituto de Astronomia UNAM Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report: We observed the field of GRB 170318B (Cholden-Brown et al., GCN 20908) 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 2017/03 19.47 to 2017/03 19.51 UTC (19.76 to 20.76 hours after the BAT trigger), obtaining a total of 0.71 hours exposure in the r and i bands and 0.30 hours exposure in the Z, Y, J, and H bands. For a source within the Swift-XRT enhanced error circle (Goad et al., GCN 20910), in comparison with the USNO-B1 and 2MASS catalogs, we obtain the following upper limits (3-sigma): r > 25.64 i > 24.39 Z > 22.65 Y > 22.43 J > 21.38 H > 20.98 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir.
GCN 20923 table
GRB_name GRB170318B
GCN_number 20923
Detection_method Swift-BAT Det
ra 284.2290°
decl 6.3350°
Circular_text TITLE: GCN CIRCULAR NUMBER: 20923 SUBJECT: GRB 170318B: Swift-BAT refined analysis DATE: 17/03/20 01:21:46 GMT FROM: Hans Krimm at NASA-GSFC/NSF H. A. Krimm (NSF/USRA), S. D. Barthelmy (GSFC), A. Cholden-Brown (PSU), J. R. Cummings (CPI), 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-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 170318B (trigger #743086) (Cholden-Brown, et al., GCN Circ. 20908). The BAT ground-calculated position is RA, Dec = 284.229, 6.335 deg which is RA(J2000) = 18h 56m 54.9s Dec(J2000) = +06d 20' 04.5" with an uncertainty of 3.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 67%. The mask-weighted light curve shows an initial symmetric pulse of duration ~20 sec from about T-15 sec to T+5 sec. This is followed by low-level extended emission from ~T+30 to T+160 sec. T90 (15-350 keV) is 160.0 +- 35.8 sec (estimated error including systematics). The time-averaged spectrum from T-15.33 to T+160.67 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.84 +- 0.59. The fluence in the 15-150 keV band is 5.5 +- 1.9 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-7.83 sec in the 15-150 keV band is 0.1 +- 0.1 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/743086/BA/
GCN 20957 table
GRB_name GRB170318B
GCN_number 20957
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 20957 SUBJECT: GRB 170318B: 15 GHz upper limits from AMI DATE: 17/03/31 13:32:06 GMT FROM: Kunal Mooley at Oxford U K. P. Mooley (Hintze Fellow, Oxford) , T. D. Staley, R. P. Fender (Oxford), G. E. Anderson (Curtin), T. Cantwell (Manchester), D. Titterington, S. H. 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 170318B (Cholden-Brown et al., GCN 20908) 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 Mar 19.11, Mar 21.17 and Mar 23.24 (UT) do not reveal any radio source at the XRT location (Goad et al., GCN 20910), with 3sigma upper limits of 300 uJy, 150 uJy and 315 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/.