Gamma-ray Burst 100924A

(All information courtesy of the instrument teams.)

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Results of Observations

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Fri 24 Sep 10 03:58:23 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      48
TRIGGER_NUM:     306993490
GRB_RA:            3.533d {+00h 14m 08s} (J2000),
                   3.673d {+00h 14m 41s} (current),
                   2.884d {+00h 11m 32s} (1950)
GRB_DEC:         +28.167d {+28d 09' 60"} (J2000),
                 +28.226d {+28d 13' 34"} (current),
                 +27.889d {+27d 53' 19"} (1950) 
GRB_ERROR:       9.88 [deg radius, statistical plus systematic]
GRB_INTEN:       430 [cnts/sec]
DATA_SIGNIF:     21.60 [sigma] 
INTEG_TIME:      1.024 [sec]
GRB_DATE:        15463 TJD;   267 DOY;   10/09/24
GRB_TIME:        14288.32 SOD {03:58:08.32} UT 
GRB_PHI:         144.00 [deg]  
GRB_THETA:        50.00 [deg]  
DATA_TIME_SCALE: 1.0240 [sec]  
HARD_RATIO:      0.57
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      94%  GRB
2nd_MOST_LIKELY:   4%  Generic Transient
DETECTORS:       0,0,0, 0,0,0, 0,0,0, 1,0,1, 0,0,
SUN_POSTN:       180.92d {+12h 03m 41s}   -0.40d {-00d 23' 58"}
SUN_DIST:        152.05 [deg]   Sun_angle= 11.8 [hr] (West of Sun) 
MOON_POSTN:        7.00d {+00h 27m 59s}   +8.44d {+08d 26' 09"}
MOON_DIST:        20.04 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      113.01,-33.99 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       15.11, 24.30 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.
COMMENTS:        This trigger occurred at longitude,latitude = 265.25,-20.13 [deg].

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Fri 24 Sep 10 03:58:43 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      58
TRIGGER_NUM:     306993490
GRB_RA:          356.720d {+23h 46m 53s} (J2000),
                 356.857d {+23h 47m 26s} (current),
                 356.084d {+23h 44m 20s} (1950)
GRB_DEC:         +14.530d {+14d 31' 48"} (J2000),
                 +14.590d {+14d 35' 23"} (current),
                 +14.252d {+14d 15' 08"} (1950) 
GRB_ERROR:       2.58 [deg radius, statistical only]
DATA_SIGNIF:     22.70 [sigma] 
DATA_INTERVAL:   2.048 [sec]   
GRB_DATE:        15463 TJD;   267 DOY;   10/09/24
GRB_TIME:        14288.32 SOD {03:58:08.32} UT 
GRB_PHI:         162.00 [deg]
GRB_THETA:        55.00 [deg]  
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   413 (Gnd S/W Version number)
SUN_POSTN:       180.92d {+12h 03m 41s}   -0.40d {-00d 23' 58"}
SUN_DIST:        165.25 [deg]   Sun_angle= -11.7 [hr] (East of Sun)
MOON_POSTN:        7.00d {+00h 28m 00s}   +8.44d {+08d 26' 13"}
MOON_DIST:        11.68 [deg]  
MOON_ILLUM:      99 [%]
GAL_COORDS:      100.36,-45.49 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:        2.90, 14.61 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.
COMMENTS:        This Notice was ground-generated -- not flight-generated.

GCN NOTICE

TITLE:          GCN/INTEGRAL NOTICE
NOTICE_DATE:    Fri 24 Sep 10 03:59:00 UT
NOTICE_TYPE:    INTEGRAL SPI ACS Trigger
TRIGGER_NUM:    6062,   Sub_Num: 0
GRB_INTEN:      9.57 [sigma]
GRB_TIME:       14287.51 SOD {03:58:07.51} UT
GRB_DATE:       15463 TJD;   267 DOY;   10/09/24 
COMMENTS:       INTEGRAL SPI_ACS GRB Trigger.
COMMENTS:
COMMENTS:       NOTE: This SPIACS event is temporally(1.0<100sec) coincident with the FERMI_GBM event (trignum=306993490).
COMMENTS:
COMMENTS:       The SPIACS lightcurve can be found at:
COMMENTS:       ftp://isdcarc.unige.ch/arc/FTP/ibas/spiacs/2010-09/2010-09-24T03-58-07.2745-12012-00007-0.lc

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 24 Sep 10 04:05:47 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     434843,   Seg_Num: 0
GRB_RA:            0.671d {+00h 02m 41s} (J2000),
                   0.809d {+00h 03m 14s} (current),
                   0.031d {+00h 00m 07s} (1950)
GRB_DEC:          +7.015d {+07d 00' 54"} (J2000),
                  +7.075d {+07d 04' 29"} (current),
                  +6.737d {+06d 44' 12"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       5863 [cnts]    Image_Peak=307 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   147     E_range: 25-100 keV
BKG_INTEN:       28460 [cnts]
BKG_TIME:        14273.79 SOD {03:57:53.79} UT
BKG_DUR:         8 [sec]
GRB_DATE:        15463 TJD;   267 DOY;   10/09/24
GRB_TIME:        14288.89 SOD {03:58:08.89} UT
GRB_PHI:          99.48 [deg]
GRB_THETA:        33.11 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     40.89 [sigma]
IMAGE_SIGNIF:    12.02 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  +1  -5  +0 +99  +0 
SUN_POSTN:       180.93d {+12h 03m 42s}   -0.40d {-00d 24' 05"}
SUN_DIST:        173.33 [deg]   Sun_angle= -12.0 [hr] (East of Sun)
MOON_POSTN:        7.05d {+00h 28m 13s}   +8.46d {+08d 27' 37"}
MOON_DIST:         6.34 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      102.11,-53.87 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:        3.42,  6.17 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This Notice was delayed by more than 60 sec past the end of the trigger integration interval;  
COMMENTS:        probably due to it occurring during a Malindi downlink session.  
COMMENTS:        This is a rate 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 = 259.24,19.06 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 24 Sep 10 04:06:14 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     434843,   Seg_Num: 0
GRB_RA:            0.671d {+00h 02m 41s} (J2000),
                   0.809d {+00h 03m 14s} (current),
                   0.031d {+00h 00m 07s} (1950)
GRB_DEC:          +7.015d {+07d 00' 54"} (J2000),
                  +7.075d {+07d 04' 29"} (current),
                  +6.737d {+06d 44' 12"} (1950)
GRB_DATE:        15463 TJD;   267 DOY;   10/09/24
GRB_TIME:        14288.89 SOD {03:58:08.89} UT
TRIGGER_INDEX:   147
GRB_PHI:          99.48 [deg]
GRB_THETA:        33.11 [deg]
DELTA_TIME:      -70.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     40.89 [sigma]
IMAGE_SIGNIF:    12.02 [sigma]
LC_URL:          sw00434843000msb.lc
SUN_POSTN:       180.93d {+12h 03m 42s}   -0.40d {-00d 24' 05"}
SUN_DIST:        173.33 [deg]   Sun_angle= -12.0 [hr] (East of Sun)
MOON_POSTN:        7.06d {+00h 28m 14s}   +8.46d {+08d 27' 42"}
MOON_DIST:         6.34 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      102.11,-53.87 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:        3.42,  6.17 [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 a rate 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 = 259.24,19.06 [deg].

GCN Circular #11294
V. Mangano (INAF-IASFPA), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (NASA/UMBC), N. Gehrels (NASA/GSFC), E. A. Hoversten (PSU), C. B. Markwardt (NASA/GSFC) and B. Sbarufatti (INAF-OAB/IASFPA) report on behalf of the Swift Team:
At 03:58:08 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 100924A (trigger=434843). Swift did not slew to the burst. The BAT on-board calculated location is RA, Dec 0.671, +7.015 which is
```
   RA(J2000) = 00h 02m 41s
   Dec(J2000) = +07d 00' 54"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multi-peaked structure with a duration of about 90 sec. The peak count rate was ~5457 counts/sec (15-350 keV), at ~0 sec after the trigger.
Due to an Moon observing constraint, Swift cannot slew to the BAT position until 13:21 UT on 2010 September 25. There will thus be no XRT or UVOT data for this trigger before this time.
Burst Advocate for this burst is V. Mangano (vanessa AT ifc.inaf.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.)
GCN Circular #11295
S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), V. Mangano (INAF-IASFPA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (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 100924A (trigger #434843) (Mangano, et al., GCN Circ. 11294). The BAT ground-calculated position is RA, Dec = 0.672, 7.004 deg which is
```
   RA(J2000)  =  00h 02m 41.3s 
   Dec(J2000) = +07d 00' 15.0" 
```
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 25%.
The mask-weighted light curve shows an initial cluster of two peaks starting at ~T-4 sec, peaking at ~T_zero, and returning to essentially background at ~T+20 sec. The second cluster has approximately 8 peakis starting at ~T+20 sec, with main peaks at ~T+35, +45, +52, +60, amd +68, and returning to background around T+120 sec. T90 (15-350 keV) is 96.0 +- 16.0 sec (estimated error including systematics).
The time-averaged spectrum from T-15.1 to T+128.9 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.53 +- 0.06. The fluence in the 15-150 keV band is 8.3 +- 0.3 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+56.40 sec in the 15-150 keV band is 1.5 +- 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/434843/BA/
GCN Circular #11297
P. Schady, T. Kruehler, and J. Greiner (all MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 100924A (Mangano et al., GCN 11294) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPI/ESO telescope at La Silla Observatory (Chile).
Observations started at 04:32 UT on September 24, 0.57 hours after the GRB and were performed under very challenging observing conditions, in particular a full moon at close distance. A second epoch of imaging was performed starting at 00:36 UT on September 25.
In the first epoch we detect a bright point source in all channels at:
```
RA = 00:02:42.26
Dec = 07:00:02.8
```
inside the refined BAT error circle (Barthelmy et al., GCN 11295) and with a preliminary magnitude of r' = 17.19. Both, photometry and astrometry have been tied to the SDSS catalog. The object faded below r' > 20 in the second epoch and is not present in the much deeper archival SDSS frames. We hence conclude that this is the optical/NIR afterglow of GRB 100924A.
GCN Circular #11311
David Gruber (MPE) reports on behalf of the Fermi GBM Team:
"At 03:58:08.32 UT on 24 September 2010, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 100924A (trigger 306993490 / 100924165). which was also detected by the Swift-BAT (Mangano et al. 2010, GCN 11294). The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 57 degrees.
This burst was also independently detected by INTEGRAL SPI-ACS.
The GBM light curve shows a bright initial peak with a duration (T90) of about 9.0 +/- 0.4 s (50-300 keV). Fermi entered the SAA ~ 35 s after the trigger. Thus, the observation of additional emission episodes, as reported in Mangano et al. 2010, GCN 11294, was not possible.
The time-averaged spectrum from T0+0.003 s to T0+9.088 s is best fit by a simple power law function with index -1.59 +0.02/-0.02 (Castor C-STAT 1767 for 725 d.o.f.).
The event fluence (10-1000 keV) in this time interval is (3.33 +/- 0.04)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.384 s in the 10-1000 keV band is 7.3 +/- 0.2 ph/s/cm^2.
GCN Circular #11313
S. Sugita (Nagoya U.), T. Uehara, Y. Hanabata, T. Takahashi, Y. Fukazawa (Hiroshima U.), N. Vasquez (Tokyo Tech.) K. Yamaoka (Aoyama Gakuin U.), Y. Terada, M. Tashiro, W. Iwakiri, K. Takahara, T. Yasuda (Saitama U.), M. Ohno, M. Suzuki, M. Kokubun, T. Takahashi (ISAS/JAXA), Y. E. Nakagawa, T. Tamagawa (RIKEN), N. Ohmori, A. Daikyuji, Y. Nishioka, M. Yamauchi (Univ. of Miyazaki), Y. Urata, P. Tsai (NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo), S. Hong (Nihon U.), on behalf of the Suzaku WAM team, report:
The multi-spiked long GRB 100924A (Swift/BAT trigger #434843, GCN 11294; Mangano et al.,) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 03:58:09.027 UT (=T0).
The observed light curve shows a multi-peaked structure starting at T0-1s, ending at T0+65s with a duration (T90) of about 60 seconds. The fluence in 100 - 1000 keV was 5.90 (+0.86/-0.84) x 10^-6 erg/cm^2. The 1-s peak flux measured from T0s was 1.44 (+-0.23) photons/cm^2/s in the same energy range.
Preliminary result shows that the time-averaged spectrum from T0-1s to T0+65s is well fitted by a single power-law with a photon index of 2.55 (+0.38/-0.29) (chi^2/d.o.f = 25.1/15). All the quoted errors are at statistical 90% confidence level.
The light curves for this burst are available at: http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html

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Jochen Greiner, last update: 24-Sep-2010 [Disclaimer]