Gamma-ray Burst 090401

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Wed 01 Apr 09 00:02:15 UT
  NOTICE_TYPE:     Swift-BAT GRB Position
  TRIGGER_NUM:     348128,   Seg_Num: 0
  GRB_RA:          350.909d {+23h 23m 38s} (J2000),
                   351.022d {+23h 24m 05s} (current),
                   350.294d {+23h 21m 11s} (1950)
  GRB_DEC:         +29.767d {+29d 45' 60"} (J2000),
                   +29.817d {+29d 49' 03"} (current),
                   +29.492d {+29d 29' 31"} (1950)
  GRB_ERROR:       3.00 [arcmin radius, statistical only]
  GRB_INTEN:       0 [cnts]    Image_Peak=1730 [image_cnts]
  TRIGGER_DUR:     64.000 [sec] 
  TRIGGER_INDEX:   20000     E_range: 15-50 keV
  BKG_INTEN:       0 [cnts]
  BKG_TIME:        0.00 SOD {00:00:00.00} UT
  BKG_DUR:         0 [sec]
  GRB_DATE:        14922 TJD;    91 DOY;   09/04/01
  GRB_TIME:        59.37 SOD {00:00:59.37} UT
  GRB_PHI:         -124.80 [deg]
  GRB_THETA:        36.37 [deg]
  SOLN_STATUS:     0x13
  RATE_SIGNIF:     0.00 [sigma]
  IMAGE_SIGNIF:    10.41 [sigma]
  MERIT_PARAMS:     +1  +0  +0  +6  +1  +0 -100  +0 -85  +0 
  SUN_POSTN:        10.48d {+00h 41m 56s}   +4.51d {+04d 30' 32"}
  SUN_DIST:         31.28 [deg]   Sun_angle= 1.3 [hr] (West of Sun)
  MOON_POSTN:       79.07d {+05h 16m 17s}  +26.82d {+26d 49' 09"}
  MOON_DIST:        75.48 [deg]
  MOON_ILLUM:      32 [%]
  GAL_COORDS:      101.08,-29.35 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:        4.78, 30.67 [deg] ecliptic lon,lat of the burst (or transient)
  COMMENTS:        SWIFT-BAT GRB Coordinates.  
  COMMENTS:        This is an image trigger.  (The RATE_SIGNIF & BKG_{INTEN, TIME, DUR} are undefined.)  
  COMMENTS:        A point_source was found.  
  COMMENTS:        This does not match any source in the on-board catalog.  
  COMMENTS:        This does not match any source in the ground catalog.  
  COMMENTS:        This is a GRB.  
  COMMENTS:        This trigger occurred at longitude,latitude = 146.07,-12.11 [deg].  
  

• red DSS finding chart ps-file
  
  
• GCN NOTICE
  

  TITLE:        GCN/SIMBAD_NED NOTICE
  NOTICE_DATE:  Wed Apr  1 00:02:21 UTC 2009
  NOTICE_TYPE:  Swift-BAT Position search
  TRIGGER_NUM:  348128
  RA:           350.9086 (J2000)
  DEC:          29.7666 (J2000)
   
  SIMBAD search for BAT_RA,Dec=350.9086,29.7666,radius=10.0arcmin
   
  Num   RA         Dec                    Name                        Type  Num_Pub  Distance
  
   1 350.88332917  29.71083056       1RXS J232332.0+294239                X   0      3.60
   2 350.88332917  29.71083056       1RXS J232332.0+294239                X   0      3.60
   3 351.01378292  29.67271389                   HD 220501               UV   3      7.86
   
   
   
  NED search for BAT_RA,Dec=350.9086,29.7666,radius=10.0arcmin
   
  Num    RA           Dec       Name                           Type      Distance
  
   1   350.888958    29.727361  2MASX J23233333+2943385       , IrS      2.60
   2   350.841500    29.714361  2MASX J23232195+2942517       , IrS      4.70
   3   350.863042    29.696806  2MASX J23232712+2941484       , IrS      4.80
   4   350.832125    29.657083  2MASX J23231972+2939257       , IrS      7.70
   5   351.033542    29.859444  2MASX J23240804+2951342       , IrS      8.60
   6   350.954125    29.626694  NVSS J232348+293736           , RadioS   8.70
   7   350.920917    29.613278  NVSS J232341+293647           , RadioS   9.20
  

• GCN NOTICE
  

  TITLE:          GCN/INTEGRAL NOTICE
  NOTICE_DATE:    Wed 01 Apr 09 00:03:39 UT 
  NOTICE_TYPE:    INTEGRAL SPI ACS Trigger
  TRIGGER_NUM:    5492,   Sub_Num: 0
  GRB_INTEN:      9.25 [sigma]   
  GRB_TIME:       160.77 SOD {00:02:40.77} UT
  GRB_DATE:       14922 TJD;    91 DOY;   09/04/01
  COMMENTS:       INTEGRAL SPI_ACS GRB Trigger.
  COMMENTS:
  ftp://isdcarc.unige.ch/arc/FTP/ibas/spiacs/2009-04-01T00-02-40.5664-24033-00007-0.lc
  

• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Wed 01 Apr 09 00:04:52 UT
  NOTICE_TYPE:     Swift-BAT GRB Lightcurve
  TRIGGER_NUM:     348128,   Seg_Num: 0
  GRB_RA:          350.909d {+23h 23m 38s} (J2000),
                   351.022d {+23h 24m 05s} (current),
                   350.294d {+23h 21m 11s} (1950)
  GRB_DEC:         +29.767d {+29d 45' 60"} (J2000),
                   +29.817d {+29d 49' 03"} (current),
                   +29.492d {+29d 29' 31"} (1950)
  GRB_DATE:        14922 TJD;    91 DOY;   09/04/01
  GRB_TIME:        59.37 SOD {00:00:59.37} UT
  TRIGGER_INDEX:   20000
  GRB_PHI:         -124.80 [deg]
  GRB_THETA:        36.37 [deg]
  DELTA_TIME:      0.00 [sec]
  TRIGGER_DUR:     64.000 [sec] 
  SOLN_STATUS:     0x13
  RATE_SIGNIF:     0.00 [sigma]
  IMAGE_SIGNIF:    10.41 [sigma]
  LC_URL:          sw00348128000msb.lc
  SUN_POSTN:        10.48d {+00h 41m 56s}   +4.51d {+04d 30' 35"}
  SUN_DIST:         31.28 [deg]   Sun_angle= 1.3 [hr] (West of Sun)
  MOON_POSTN:       79.10d {+05h 16m 24s}  +26.82d {+26d 49' 10"}
  MOON_DIST:        75.50 [deg]
  MOON_ILLUM:      32 [%]
  GAL_COORDS:      101.08,-29.35 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:        4.78, 30.67 [deg] ecliptic lon,lat of the burst (or transient)
  COMMENTS:        SWIFT-BAT GRB Lightcurve.  
  COMMENTS:           
  COMMENTS:        The next comments were copied from the BAT_POS Notice:  
  COMMENTS:        This is an image trigger.  
  COMMENTS:        A point_source was found.  
  COMMENTS:        This does not match any source in the on-board catalog.  
  COMMENTS:        This does not match any source in the ground catalog.  
  COMMENTS:        This is a GRB.  
  COMMENTS:        This trigger occurred at longitude,latitude = 146.07,-12.11 [deg].  
  

  
• GCN Circular #9062
  P. Schady (MSSL-UCL), S. D. Barthelmy (GSFC), N. Gehrels (NASA/GSFC), S. T. Holland (CRESST/USRA/GSFC), H. A. Krimm (CRESST/GSFC/USRA), C. B. Markwardt (CRESST/GSFC/UMD), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), A. M. Parsons (GSFC), B. A. Rowlinson (U Leicester) and L. Vetere (PSU) report on behalf of the Swift Team:
  At 00:00:59 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 090401 (trigger=348128). The BAT on-board calculated location is RA, Dec 350.909, +29.767 which is

     RA(J2000)  =  23h 23m 38s
     Dec(J2000) = +29d 46' 00"
  

  with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a small peak at ~T+30 sec and then two large peaks at ~T+100 and ~T+120 sec. The peak count rate was ~4000 counts/sec (15-350 keV), at ~120 sec after the trigger.
  Due to an observing constraint, Swift cannot slew to the BAT position. It will not be possible to observe until 2nd May due to a sun constraint. There will thus be no XRT or UVOT data for this trigger.
  Burst Advocate for this burst is P. Schady (ps AT mssl.ucl.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 Circular #9064
  G. Sato (ISAS), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), P. Schady (MSSL-UCL), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team):
  Using the data set from T-239 to T+713 sec from the recent telemetry downlink, we report further analysis of BAT GRB 090401 (trigger #348128) (Schady, et al., GCN Circ. 9062). The BAT ground-calculated position is RA, Dec = 350.920, 29.762 deg, which is

     RA(J2000)  =  23h 23m 40.8s 
     Dec(J2000) = +29d 45' 44.1" 
  

  with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 38%.
  The mask-weighted light curve starts out at T-20 sec when the burst location first came into the BAT FOV during a planned-target slew maneuver. There is evidence for emission starting prior to burst coming to the FOV. There are two small peaks at T+0 and T+30 sec. Then comes the main emission with a series of at least 7 overlapping peaks starting at ~T+95 sec and returning to background at ~T+190 sec. T90 (15-350 keV) is 112 +- 15 sec (estimated error including systematics).
  The time-averaged spectrum from T-9.4 to T+160.0 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.70 +- 0.05. The fluence in the 15-150 keV band is 1.1 +- 0.0 x 10^-5 erg/cm2. The 1-sec peak photon flux measured from T+122.05 sec in the 15-150 keV band is 10.9 +- 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/348128/BA/
• GCN Circular #9071
  S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report:
  The most intense part of the long GRB 090401A (Swift-BAT trigger #348128: Schady et al., GCN 9062; Sato et al., GCN 9064) triggered Konus-Wind at T0=170.845 s UT (00:02:50.845).
  The burst light curve shows a weak emission starting at ~T0-120s followed by the main multipeaked part at ~T0-24s, which had a duration of ~40s. There is a hint of an earlier emission.
  As observed by Konus-Wind the burst had a fluence of 2.14(-0.17, +0.19)x10^-5 erg/cm2, and a 256-ms peak flux measured from T0+7.648 s of 2.79(-0.42, +0.44)x10^-6 erg/cm2/s (both in the 20 keV - 1 MeV energy range).
  The spectrum of the most intense part (from T0 to T0+16.640 s) can be fitted (in the 20 keV - 1 MeV range) by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.26(-0.14, +0.15), and Ep = 218(-34, +51) keV (chi2 = 87.9/60 dof). Fitting by GRB (Band) model yields the same alpha and Ep, and only an upper limit on the high energy photon index: beta < -2.3 (chi2 = 87.9/59 dof).
  All the quoted errors are at the 90% confidence level.
  The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB090401_T00170/
• GCN Circular #9085
  M. Suzuki, M. Ohno, M. Kokubun, T. Takahashi (ISAS/JAXA), N. Kodaka, W. Iwakiri, M. Tashiro, Y. Terada, Y. Urata, A. Endo, K. Onda, K. Morigami, T. Sugasahara (Saitama U.), T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo), S. Sugita, K. Yamaoka (Aoyama Gakuin U.), Y. E. Nakagawa, T. Tamagawa (RIKEN), T. Uehara, T. Takahashi, Y. Fukazawa, C. Kira, Y. Hanabata (Hiroshima U.), E. Sonoda, M. Yamauchi, H. Tanaka, R. Hara, N. Ohmori, K. Kono, H. Hayashi (Univ. of Miyazaki), S. Hong (Nihon U.), N. Vasquez (Tokyo Tech.), on behalf of the Suzaku WAM team, report:
  The bright long GRB090401A (Swift/BAT trigger #348128; Schady et al., GCN 9062; Sato et al., GCN 9064) was detected by the the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 00:02:34.509 UT (=T0).
  The observed light curve shows a multi-peaked structure lasting from T0-5s to T0+38s. There is also a weak precursor starting at ~T0-103s, resulting in the total duration (T90) of about 112 seconds. The fluence in 100 - 1000 keV was 1.37(-0.10,+0.08) x10^-5 erg/cm^2. The 1-s peak flux measured from T0+27s was 5.1(-0.4,+0.5) photons/cm^2/s in the same energy range.
  Preliminary result shows that the time-averaged spectrum from T0-5s to T0+38s is fitted by a single power-law with a photon index of 2.14 (-0.13,+0.14) (chi^2/d.o.f = 21.4/24). 3 % systematic errors were included in low energy channels. All the quoted errors are at 90% confidence level.
  The light curves with 1-sec time resolution for this burst will be appeared at: http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/untrig/grb_table.html
• GCN Report 206.1
  GCN_Report 206.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_206_1.pdf by P. Schady at MSSL-UCL titled: "Final Results on Swift GRB 090401A"