GRB170405A

This page lists all entries on GRB170405A in GRBweb

Summary Fermi GBM IPN Swift Fermi LAT GCN 20984 GCN 20985 GCN 20986 GCN 20987 GCN 20988 GCN 20989 GCN 20990 GCN 20991 GCN 20992 GCN 20994 GCN 20995 GCN 20996 GCN 20997 GCN 20998 GCN 20999 GCN 21000 GCN 21003

Summary table
Variable Value Source
GRB_name_Fermi GRB170405777
T0 18:39:22.886 UTC Fermi_GBM
ra 219.8280° Swift
decl -25.2432° Swift
pos_error 5.44e-05° Swift
T90 78.593 s Fermi_GBM
T90_error 0.572 s Fermi_GBM
T90_start 18:39:30.310 UTC Fermi_GBM
fluence 7.40e-05 erg/cm² Fermi_GBM
fluence_error 6.62e-08 erg/cm² Fermi_GBM
redshift 3.5100
T100 189.814 s
GBM_located False
mjd 57848.77734821759 Fermi_GBM
Fermi GBM table
GRB_name_Fermi GRB170405777
trigger_name bn170405777
ra 219.8100°
decl -25.2439°
pos_error 2.74e+00°
datum 2017-04-05
t_trigger 18:39:22.886 UTC
T90 78.593 s
T90_error 0.572 s
T90_start 18:39:30.310 UTC
fluence 7.40e-05 erg/cm²
fluence_error 6.62e-08 erg/cm²
flux_1024 1.58e+01 erg/cm²/s
flux_1024_error 3.10e-01 erg/cm²/s
flux_1024_time 2.95e+01 erg/cm²/s
flux_64 1.85e+01 erg/cm²/s
flux_64_error 1.28e+00 erg/cm²/s
IPN table
GRB_name GRB170405A
ra 219.8083°
decl -25.2500°
pos_error 5.00e-02°
Swift table
GRB_name GRB170405A
t_trigger 18:39:48 UTC
ra 219.8280°
decl -25.2432°
pos_error 5.44e-05°
T90 164.7 s
fluence 3.70e-06 erg/cm²
redshift 3.5100
Fermi LAT table
GRB_name_Fermi GRB170405777
GRB_name GRB170405A
MET 513110367.0
datum 2017-04-05
t_trigger 18:39:23 UTC
ra 219.8280°
decl -25.2430°
pos_error 5.00e+00°
GCN 20984 table
GRB_name GRB170405A
GCN_number 20984
Detection_method Swift Det
t_trigger 18:39:48 UTC
ra 219.8100°
decl -25.2440°
Circular_text TITLE: GCN CIRCULAR NUMBER: 20984 SUBJECT: GRB 170405A: Swift detection of a burst with an optical counterpart DATE: 17/04/05 18:50:16 GMT FROM: Scott Barthelmy at NASA/GSFC E. Troja (NASA/GSFC/UMCP), S. D. Barthelmy (GSFC), D. N. Burrows (PSU), S. B. Cenko (GSFC), A. Cholden-Brown (PSU), A. D'Ai (INAF-IASFPA), F. E. Marshall (NASA/GSFC) and M. H. Siegel (PSU) report on behalf of the Swift Team: At 18:39:48 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 170405A (trigger=745797). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 219.810, -25.244, which is RA(J2000) = 14h 39m 14s Dec(J2000) = -25d 14' 36" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows multiple peaks with a duration of about 180 sec. The peak count rate was ~4500 counts/sec (15-350 keV), at ~4 sec after the trigger. The XRT began observing the field at 18:41:49.0 UT, 120.6 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 219.8290, -25.2438 which is equivalent to: RA(J2000) = +14h 39m 18.96s Dec(J2000) = -25d 14' 37.7" with an uncertainty of 4.7 arcseconds (radius, 90% containment). This location is 61 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. UVOT took a finding chart exposure of 150 seconds with the White filter starting 128 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 14:39:18.72 = 219.82800 DEC(J2000) = -25:14:35.3 = -25.24315 with a 90%-confidence error radius of about 0.61 arc sec. This position is 3.7 arc sec. from the center of the XRT error circle. The estimated magnitude is 16.18 with a 1-sigma error of about 0.14. No correction has been made for the expected extinction corresponding to E(B-V) of 0.09. Burst Advocate for this burst is E. Troja (eleonora.troja 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.)
GCN 20985 table
GRB_name GRB170405A
GCN_number 20985
Detection_method Swift-XRT Det
ra 219.8277°
decl -25.2437°
Circular_text TITLE: GCN CIRCULAR NUMBER: 20985 SUBJECT: GRB 170405A: Enhanced Swift-XRT position DATE: 17/04/05 20:38:10 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 368 s of XRT Photon Counting mode data and 1 UVOT images for GRB 170405A, 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 = 219.82767, -25.24368 which is equivalent to: RA (J2000): 14h 39m 18.64s Dec (J2000): -25d 14' 37.3" with an uncertainty of 1.8 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 20986 table
GRB_name GRB170405A
GCN_number 20986
Detection_method Fermi GBM Det
t_trigger 18:39:22.890 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 20986 SUBJECT: GRB 170405A: Fermi GBM observation DATE: 17/04/05 22:51:57 GMT FROM: C. Michelle Hui at MSFC/Fermi-GBM C. M. Hui (MSFC) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: At 18:39:22.89 UT on 05 April 2017, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 170405A (trigger 513110367/170405777), which was also detected by Swift (Troja et al. 2017, GCN 20984). The GBM on-ground location is consistent with the Swift position. The trigger resulted in an Autonomous Repoint Request (ARR) by the GBM Flight Software owing to the high peak flux of the GRB. This ARR was accepted and the spacecraft slewed to the GBM in-flight location. The initial angle from the Fermi LAT boresight is 52 degrees. The GBM light curve shows multiple peaks with a duration (T90) of about 78.6 s (50-300 keV). The time-averaged spectrum from T0+7.2 s to T0+86.0 s is adequately fit by a power law function with an exponential high-energy cutoff. The power law index is -1.01 +/- 0.01 and the cutoff energy, parameterized as Epeak, is 355.2 +/- 8.6 keV. The event fluence (10-1000 keV) in this time interval is (7.85 +/- 0.07)E-05 erg/cm^2. The 1s peak photon flux measured starting from T0+29.5 s in the 10-1000 keV band is 15.8 +/- 0.3 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog.
GCN 20987 table
GRB_name GRB170405A
GCN_number 20987
Detection_method Fermi LAT Det
t_trigger 18:39:22.890 UTC
ra 219.3700°
decl -25.2300°
Circular_text TITLE: GCN CIRCULAR NUMBER: 20987 SUBJECT: GRB 170405A: Fermi-LAT detection DATE: 17/04/06 00:24:15 GMT FROM: Giacomo Vianello at SLAC G.Vianello (Stanford), D.Kocevski (NASA/MSFC) report on behalf of the Fermi-LAT team: At 18:39:22.89 on April, 05, 2017 Fermi-LAT detected high-energy emission from GRB 170405A, which was also detected by Swift (Troja et al., GCN 20984) and Fermi/GBM (trigger 513110367/170405777). The best LAT on-ground location is found to be: RA, Dec = 219.37, -25.23 (J2000) with an error radius of 0.51 deg (90 % containment, statistical error only). This was 53 deg from the LAT boresight at the time of the trigger and triggered an autonomous repoint of the spacecraft. This position is compatible with the XRT position reported by Evans et al. (GCN 20985). The data from the Fermi-LAT show a significant increase in the event rate that is spatially and temporally correlated with the trigger with high significance. More than 13 events have been observed above 100 MeV which are spatially and temporally correlated with the GRB. The highest-energy photon is a 900 MeV event which is observed 445 seconds after the GBM trigger. We note that roughly 5 ks of data are currently available. We will provide an update, if necessary, as more data become available. The Fermi-LAT point of contact for this burst is Giacomo Vianello (giacomov@stanford.edu) The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.
GCN 20988 table
GRB_name GRB170405A
GCN_number 20988
Detection_method Optical
ra 219.8280°
decl -25.2431°
Circular_text TITLE: GCN CIRCULAR NUMBER: 20988 SUBJECT: GRB 170405A: NOT optical observations DATE: 17/04/06 01:22:36 GMT FROM: Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst Daniele Malesani (DARK/NBI), K. E. Heintz (DARK/NBI and Univ. Iceland), and Tapio Pursimo (NOT) report on behalf of a larger collaboration: We observed the optical afterglow of GRB 170405A (Troja et al., GCN 20984; Hui & Meegan, GCN 20986; Vianello & Kocevski, GCN 20987) with the Nordic Optical Telescope (NOT) equipped with the ALFOSC imager. Observations were carried out in the SDSS griz filters, with a sub-optimal PSF (1.6-2.0"). Inspection of the r-band image (with mean time Apr 6.01 UT, that is 5.47 hr after the trigger) clearly shows the optical afterglow first localized by UVOT (Troja et al., GCN 20984), which has now faded to r = 21.05 +- 0.08 AB, calibrated against nearby stars from the Pan-STARRS catalog. In our images, the afterglow coordinates are perfectly consistent with the UVOT values: RA(J2000) = 14:39:18.72 Dec(J2000) = -25:14:35.3 We also note the presence of a nearby object approximately 2.3" W of the afterglow, also visible in the Pan-STARRS archival images (with a Pan-STARRS magnitude r = 21.82 +- 0.19 AB). Its relation to the GRB is not clear, but its proximity may affect the afterglow photometry.
GCN 20989 table
GRB_name GRB170405A
GCN_number 20989
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 20989 SUBJECT: GRB 170405A: TAROT Reunion observatory optical observations DATE: 17/04/06 02:22:43 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.) Thierry P. (Auragne Observatory, France), Klotz A.N.O. (Guitalens Observatory, France) report: We imaged the field of GRB 170405A detected by SWIFT (trigger 745797) with the TAROT robotic telescope (D=18cm) located at the Reunion observatory, France. The observations started 3.84h after the GRB trigger. We detected the OT (Troja et al., GCN 20984; Hui & Meegan, GCN 20986; Vianello & Kocevski, GCN 20987; Malesani, GCNC 20988): t0+3.84h to t0+3.97h : R=19.0 +/- 0.2 Magnitudes were estimated with the nearby NOMAD1 stars and are not corrected for galactic dust extinction.
GCN 20990 table
GRB_name GRB170405A
GCN_number 20990
Detection_method Other
redshift 3.5100
Circular_text TITLE: GCN CIRCULAR NUMBER: 20990 SUBJECT: GRB 170405A: Redshift from OSIRIS/GTC DATE: 17/04/06 03:10:20 GMT FROM: Antonio de Ugarte Postigo at IAA-CSIC A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), D.A. Kann (IAA-CSIC), C.C. Thoene (IAA-CSIC), L. Izzo (IAA-CSIC), N.R. Tanvir (U. Leicester), G. Lombardi (GTC, IAC), and A. Marante (GTC) report on behalf of a larger collaboration: We observed the field of GRB 170405A (Troja et al., GCN 20984; Hui & Meegan, GCN 20986; Vianello & Kocevski, GCN 20987) using OSIRIS on the 10.4m GTC at the Roque de los Muchachos observatory (La Palma, Spain). The observation consisted of 3x900s using the R1000B grism, covering the range between 3700 and 7800 Ã…. The first spectrum started at 2:14 UT (7.57 hr after the burst). On a preliminary reduction based on archival calibrations we detect a spectral continuum with strong absorption features, which we identify as due to Ly-alpha, SiII, OI, CII, SiIV, CIV, FeII and AlII at a common redshift of z = 3.510, which we identify as the redshift of the GRB.
GCN 20991 table
GRB_name GRB170405A
GCN_number 20991
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 20991 SUBJECT: GRB 170405A: Watcher optical detection DATE: 17/04/06 07:36:55 GMT FROM: Antonio Martin-Carrillo at UCD,Space Science Group A. Martin-Carrillo (UCD), D. Murphy (UCD), L. Hanlon (UCD), H. J. van Heerden (UFS), B. van Soelen (UFS) and P. J. Meintjes (UFS) We observed the field of GRB 170405A (Troja et al, GCN 20984; Hui & Meegan, GCN 20986; Vianello & Kocevski, GCN 20987) using the 40cm UCD Watcher telescope at Boyden Observatory in South Africa. Due to bad weather observations started at 19:31:13 UT, about 51.4 minutes after the burst trigger (T0=18:39:48 UT). A faint source consistent with the UVOT coordinates reported by Troja et al. is detected on our combined images taken with the SDSS r’ filter. At a mid-time of 20:00 UT, we derive a preliminary magnitude of r’=18.0 (AB system), confirming that the source has faded since the UVOT detection. Magnitudes were calibrated using several nearby APASS stars. No correction for Galactic extinction in the direction of the GRB has been applied.
GCN 20992 table
GRB_name GRB170405A
GCN_number 20992
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 20992 SUBJECT: GRB 170405A: ISON/Terskol optical observations DATE: 17/04/06 12:12:17 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), V. Agletdinov (KIAM), A. Pozanenko (IKI), A. Volnova (IKI), I. Molotov (KIAM) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 170405A (Troja et al., GCN 20984) with K-800 (0.8m) telescope of ISON/Terskol observatory starting on April, 05 (UT) 19:12:55, i.e. 45 minutes after GRB onset. We obtained several unfiltered images of 15 s exposure. The optical afterglow Troja et al., GCN 20984; Malesani et al., GCN 20988; Klotz et al., GCN 20989; Ugarte Postigo et al., GCN 20990; Martin-Carrillo et al., GCN 20991) is clearly visible in combined images. Preliminary photometry of the afterglow is following Date UT start t-T0 Filter Exp. OT Err. UL (mid, days) (s) 2017-04-05 19:12:55 0.03139 CR 72*15 17.27 0.10 20.1 2017-04-05 19:34:33 0.04300 CR 48*15 17.96 0.13 19.8 2017-04-05 19:49:05 0.06019 CR 110*15 18.39 0.14 20.4 2017-04-05 20:23:55 0.08543 CR 110*15 19.18 0.22 20.2 2017-04-05 21:01:48 0.11099 CR 107*15 n/d n/d 18.9 Photometry is based on nearby USNO-B1.0 stars USNO-B.1_id R2 0647-0315771 15.13 0647-0315754 15.45 0647-0315872 15.34 0647-0315921 15.08 0647-0315788 14.92 Preliminary light curve of the afterglow can be found in http://grb.rssi.ru/GRB170405A/GRB170405A_light_curve.png
GCN 20994 table
GRB_name GRB170405A
GCN_number 20994
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 20994 SUBJECT: GRB 170405A: LCO FTN observations DATE: 17/04/06 13:02:36 GMT FROM: Cristiano Guidorzi at Ferrara U,Italy C. Guidorzi (U. Ferrara), S. Kobayashi, I.A. Steele (LJMU), A. Gomboc (U. Nova Gorica), C.G. Mundell (U. Bath) on behalf of a large collaboration report: We observed Swift GRB 170405A (Troja et al. GCN 20984) on April 06, from 10:23 to 11:01 UT (0.66 to 0.68 days since the GRB) with the 2-m LCO Faulkes Telescope North with the SDSS i and r filters. We do not detect the optical afterglow (Troja et al; Malesani et al. GCN 20988; Klotz et al. GCN 20989; de Ugarte Postigo et al. GCN 20990; Martin-Carrillo et al. GCN 20991; Mazaeva et al. GCN 20992) down to the following limits: Mid Time Exposure Filter Magnitude (AB) (days) (s) ------------------------------------------------------- 0.66 5x120 SDSS-R > 21.6 0.68 4x120 SDSS-I > 21.6 ------------------------------------------------------- as calibrated against nearby Pan-STARRS objects. The nearby Pan-STARRS object mentioned by Malesani et al. is clearly visible in our stacked frames.
GCN 20995 table
GRB_name GRB170405A
GCN_number 20995
Detection_method Konus-Wind Det
t_trigger 18:39:41.254 UTC
redshift 3.5100
Circular_text TITLE: GCN CIRCULAR NUMBER: 20995 SUBJECT: Konus-Wind observation of GRB 170405A DATE: 17/04/06 14:57:40 GMT FROM: Dmitry Frederiks at Ioffe Institute D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline, on behalf of the Konus-Wind team, report: The long GRB 170405A (Swift-BAT detection: Troja et al.,GCN 20984; Fermi-GBM detection: Hui & Meegan., GCN 20986; Fermi-LAT detection: Vianello & Kocevski, GCN 20987) triggered Konus-Wind at T0=67181.254 s UT (18:39:41.254) The light curve shows a multi-peaked structure with a total duration of ~100 s and a hint of a subsequent weak/soft emission lasting until ~T0+200 s. The emission is seen up to ~10 MeV. As observed by Konus-Wind, the burst had a fluence of (1.05 ± 0.12)x10^-4 erg/cm2 and a 64-ms peak energy flux, measured from T0+15.744, of (5.9 ± 0.9)x10^-6 erg/cm2 (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum (measured from T0 to T0+73.984 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.53 (-0.17,+0.19), the high energy photon index beta = -2.36 (-0.25,+0.15), the peak energy Ep = 244 (-27,+32) keV, chi2 = 98/96 dof. The spectrum near the peak count rate (measured from T0+8.448 s to T0+24.832 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.54 (-0.22,+0.24), the high energy photon index beta = -2.56 (-1.02,+0.27), the peak energy Ep = 265 (-36,+51) keV, chi2 = 71/96 dof. Assuming the redshift z=3.510 (de Ugarte Postigo et al., GCN 20990) and a standard cosmology model with H_0 = 70 km/s/Mpc, Omega_M = 0.3, and Omega_Lambda = 0.7, we estimate the following rest-frame parameters: the isotropic energy release E_iso is ~2.6x10^54 erg, the peak luminosity L_iso is ~6.6x10^53 erg/s, and the rest-frame peak energy of the time-integrated spectrum, Ep,i, is ~1100 keV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB170405_T67181/ All the quoted errors are estimated at the 90% confidence level. All the presented results are preliminary. [GCN OPS NOTE(06apr17): Per author's request, in the first paragraph the V&K CirNum was changed from "20827" to "20987", and in the 6th paragraph the de Ugarte Postigo CircNum was changed from "20104" to "20990".]
GCN 20996 table
GRB_name GRB170405A
GCN_number 20996
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 20996 SUBJECT: GRB 170405A: RATIR Optical and NIR Observations DATE: 17/04/06 15:58:54 GMT FROM: Eleonora Troja at GSFC Eleonora Troja (GSFC), Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara(UVI), 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 170405A (Troja, et al., GCN 20984) 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 2017/04 6.23 to 2017/04 6.48 UTC (10.93 to 16.85 hours after the BAT trigger), obtaining a total of 3.84 hours exposure in the r and i bands and 1.62 hours exposure in the Z, Y, J, and H bands. For a source within the Swift-UVOT error circle (Troja, et al., GCN 20984), in comparison with the USNO-B1 and 2MASS catalogs, we obtain the following detections: r 22.67 +/- 0.05 i 21.83 +/- 0.04 Z 21.26 +/- 0.07 Y 21.14 +/- 0.07 J 20.75 +/- 0.07 H 20.56 +/- 0.08 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. The nearby object noted by Malesani et al., (GCN 20988) is detected in all our images and might affect our photometric measurements. The reported values should be therefore considered as preliminary. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir. Further observations are planned.
GCN 20997 table
GRB_name GRB170405A
GCN_number 20997
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 20997 SUBJECT: GRB 170405A: Swift-XRT refined Analysis DATE: 17/04/06 17:03:32 GMT FROM: Phil Evans at U of Leicester K.L. Page (U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Cholden-Brown (PSU), S. J. LaPorte (PSU), J.A. Kennea (PSU), B. Mingo (U. Leicester), A.P. Beardmore (U. Leicester) and report on behalf of the Swift-XRT team: report on behalf of the Swift-XRT team: We have analysed 6.5 ks of XRT data for GRB 170405A, from 111 s to 57.3 ks after the BAT trigger. The data comprise 489 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 late-time light curve (from T0+4.5 ks) can be modelled with a power-law decay with a decay index of alpha=1.66 (+0.14, -0.12). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.592 (+0.027, -0.019). The best-fitting absorption column is consistent with the Galactic value of 8.7 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.84 (+0.09, -0.07) and a best-fitting absorption column consistent with the Galactic value. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.6 x 10^-11 (4.2 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Galactic foreground: 8.7 x 10^20 cm^-2 Intrinsic column: 8.7 (+68.1, -0.0) x 10^20 cm^-2 at z=3.51 Photon index: 1.84 (+0.09, -0.07) If the light curve continues to decay with a power-law decay index of 1.66, the count rate at T+24 hours will be 5.5 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.0 x 10^-13 (2.3 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/00745797. This circular is an official product of the Swift-XRT team.
GCN 20998 table
GRB_name GRB170405A
GCN_number 20998
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 20998 SUBJECT: GRB 170405A: Etelman observatory optical observations DATE: 17/04/06 19:41:45 GMT FROM: Bruce Gendre at UVI B. Gendre (UVI), N. Orange (OrangeWave Innovative Science, LLC), D. Morris (UVI), A. Cucchiara (UVI), D. Drost (UVI), T. Giblin (USAF Academy), J. Hakkila (College of Charleston), A. Klotz (IRAP), J. Neff (NSF), D. Smith (UVI), J. Staff (UVI), P. Thierry (Auragne Observatory), R. Watlington (UVI), and L. Wentlent (UVI) report: We observed the field of GRB 170405A (Troja et al, GCN 20984; Hui & Meegan, GCN 20986; Vianello & Kocevski, GCN 20987) with the 0.5m Virgin Island Robotic Telescope (VIRT) on February the 6th, starting at 6:15 UT (11.6 hours after the trigger). We performed a series of exposures in the clear filter. The weather conditions were good during the observations. We co-added the exposures taken between 6h15UT (t0+11.6h) and 7h29UT (t0+12.8h), for a total exposure of 3510s. At the position of the optical afterglow reported by Malesani et al. (GCN 20988), we do not detect any optical emission, with an upper limit of R = 21.3 (Johnson system) estimated from nearby NOMAD1 stars. Magnitudes have not been corrected for Galactic extinction. The VIRT is still in its commissioning phase. This message can be cited.
GCN 20999 table
GRB_name GRB170405A
GCN_number 20999
Detection_method Swift-BAT Det
ra 219.8240°
decl -25.2360°
Circular_text TITLE: GCN CIRCULAR NUMBER: 20999 SUBJECT: GRB 170405A, Swift-BAT refined analysis DATE: 17/04/07 03:25:45 GMT FROM: Amy Lien at GSFC D. M. Palmer (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), N. Gehrels (GSFC), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), T. Sakamoto (AGU), M. Stamatikos (OSU), E. Troja (NASA/GSFC/UMCP), 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 170405A (trigger #745797) (Troja et al., GCN Circ. 20984). The BAT ground-calculated position is RA, Dec = 219.824, -25.236 deg which is RA(J2000) = 14h 39m 17.8s Dec(J2000) = -25d 14' 09.7" with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 6%. The burst was outside of the BAT calibrated field of view from T-134.3 s to T+56.7 s. The mask-weighted light curve using the “detection mask” (which covers a broader field of view, but is not well calibrated; see detail description in Markwardt et al. 2007) shows a multi-peaked structure that starts at ~T-30 s and ends at ~T+240 s. The major peak occurs at ~T+5 s. T90 (15-350 keV) is 164.7 +- 35.4 sec (estimated error including systematics). The time-averaged spectrum from T+56.7 to T+242.5 sec (i.e., when the burst is in the BAT calibrated field of view) is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.59 +- 0.12. The fluence in the 15-150 keV band is 3.7 +- 0.3 x 10^-06 erg/cm2. 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/745797/BA/
GCN 21000 table
GRB_name GRB170405A
GCN_number 21000
Detection_method Swift-UVOT Det
ra 219.8280°
decl -25.2432°
redshift 3.5100
Circular_text TITLE: GCN CIRCULAR NUMBER: 21000 SUBJECT: GRB170405A, Swift-UVOT Detection DATE: 17/04/07 06:46:05 GMT FROM: Sam LaPorte at PSU GRB 170405A: Swift/UVOT Detection S. J. LaPorte (PSU) and E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 170405A 129 s after the BAT trigger (Troja et al., GCN Circ. 20984). Consistent with previous reports (Malesani et al, GCN Circ. 20988; Martin-Carrillo et al. GCN Circ. 20991), a fading source consistent with the XRT position (Evans et al. GCN Circ. 20985) is detected in the initial UVOT exposures at: RA (J2000) = 14:39:18.73 = 219.82805 (deg.) Dec (J2000) = -25:14:35.4 = -25.24317 (deg.) with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence). The upper limits in the UV bands are consistent with the reported redshift of z = 3.51 (de Ugarte-Postigo et al, GCN Circ. 20990). Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white (fc) 129 279 147 16.01 +/- 0.03 white 747 998 143 18.09 +/- 0.07 v 618 637 20 16.31 +/- 0.14 b 543 563 20 17.34 +/- 0.13 u 287 711 265 >20.2 uvw1 667 859 39 >18.9 uvm2 815 835 19 >17.5 uvw2 593 786 39 >19.1 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.09 in the direction of the burst (Schlegel et al. 1998).
GCN 21003 table
GRB_name GRB170405A
GCN_number 21003
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 21003 SUBJECT: GRB 170405A: SMARTS optical/IR afterglow observations DATE: 17/04/09 00:35:06 GMT FROM: Bethany Cobb at GWU B. E. Cobb (GWU), reports: Using the ANDICAM instrument on the 1.3m telescope at CTIO, we obtained optical/IR imaging of the error region of GRB 170405A (GCN 20984, Troja et al.) at two epochs (with mid-exposure times of 2017-04-06 02:51 UT & 06:52 UT). For each epoch, several dithered images were obtained with total summed exposure times of 15 min in V and I and 12 min in J and K. The fading afterglow of GRB 170405A (e.g. GCN 20984, Troja et al.; GCN 20988, Malesani et al.; GCN 20989, Klotz et al.) was detected with the preliminary magnitudes (or 3-sigma limits) listed below. Note that the optical photometry is calibrated against USNO-B1.0 stars in the field, so suffers from a large photometric calibration error of about +/-0.2 magnitudes, which has not been included in the errors quoted below. The IR photometry is calibrated against 2MASS stars. Additionally, the nearby source noted by Malesani et al. (GCN 20988) is seen and is likely affecting the afterglow photometry due to its proximity. mid-exposure time post-burst (hours) I mag J mag K mag 8.19000 20.4+/-0.1 >18.5 >16.9 12.1975 21.1+/-0.1 >18.8 >16.8