Gamma-ray Burst 090708

(All information courtesy of the instrument teams.)

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 08 Jul 09 03:38:58 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     356776,   Seg_Num: 0
GRB_RA:          154.629d {+10h 18m 31s} (J2000),
                 154.762d {+10h 19m 03s} (current),
                 153.927d {+10h 15m 43s} (1950)
GRB_DEC:         +26.637d {+26d 38' 12"} (J2000),
                 +26.589d {+26d 35' 19"} (current),
                 +26.887d {+26d 53' 15"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       16036 [cnts]    Image_Peak=283 [image_cnts]
TRIGGER_DUR:     4.096 [sec] 
TRIGGER_INDEX:   300     E_range: 25-100 keV
BKG_INTEN:       141772 [cnts]
BKG_TIME:        13035.10 SOD {03:37:15.10} UT
BKG_DUR:         40 [sec]
GRB_DATE:        15020 TJD;   189 DOY;   09/07/08
GRB_TIME:        13095.26 SOD {03:38:15.26} UT
GRB_PHI:         -136.70 [deg]
GRB_THETA:        42.60 [deg]
SOLN_STATUS:     0x20000003
RATE_SIGNIF:     13.03 [sigma]
IMAGE_SIGNIF:    7.69 [sigma]
MERIT_PARAMS:     +1  +0  +0  +2  +2  -2 -100  +0 -73  +0 
SUN_POSTN:       107.49d {+07h 09m 57s}  +22.46d {+22d 27' 50"}
SUN_DIST:         42.97 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      296.40d {+19h 45m 37s}  -21.75d {-21d 45' 00"}
MOON_DIST:       144.80 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      204.82, 56.03 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      146.74, 15.01 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
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 = 152.05,20.05 [deg].  
COMMENTS:           
COMMENTS:        NOTE: This BAT event is temporally(3.0<100sec) coincident with the FERMI_GBM event (trignum=268717100).

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 08 Jul 09 03:38:35 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      44
TRIGGER_NUM:     268717100
GRB_RA:          150.483d {+10h 01m 56s} (J2000),
                 150.616d {+10h 02m 28s} (current),
                 149.784d {+09h 59m 08s} (1950)
GRB_DEC:         +22.817d {+22d 48' 60"} (J2000),
                 +22.770d {+22d 46' 14"} (current),
                 +23.058d {+23d 03' 29"} (1950) 
GRB_ERROR:       26.95 [deg radius, statistical plus systematic]
GRB_INTEN:       48 [cnts/sec] 
DATA_SIGNIF:     4.70 [sigma]
INTEG_TIME:      4.096 [sec]   
GRB_DATE:        15020 TJD;   189 DOY;   09/07/08 
GRB_TIME:        13098.46 SOD {03:38:18.46} UT
GRB_PHI:          28.98 [deg]  
GRB_THETA:        60.00 [deg]  
DATA_TIME_SCALE: 4.0960 [sec]  
HARD_RATIO:      1.00
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      88%  GRB
2nd_MOST_LIKELY:   8%  Solar Flare
DETECTORS:       0,0,1, 0,0,1, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       107.49d {+07h 09m 57s}  +22.46d {+22d 27' 50"}
SUN_DIST:         39.67 [deg]   Sun_angle= -2.9 [hr] (East of Sun)
MOON_POSTN:      296.40d {+19h 45m 36s}  -21.75d {-21d 45' 02"}
MOON_DIST:       148.39 [deg]  
MOON_ILLUM:      99 [%]
GAL_COORDS:      209.74, 51.52 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      144.56, 10.09 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.
COMMENTS:        This trigger occurred at longitude,latitude = 256.93,14.42 [deg].

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 08 Jul 09 03:39:15 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      56
TRIGGER_NUM:     268717100
GRB_RA:          140.450d {+09h 21m 48s} (J2000),
                 140.587d {+09h 22m 21s} (current),
                 139.729d {+09h 18m 55s} (1950)
GRB_DEC:         +24.180d {+24d 10' 48"} (J2000),
                 +24.139d {+24d 08' 21"} (current),
                 +24.394d {+24d 23' 37"} (1950)
GRB_ERROR:       14.04 [deg radius, statistical only]
DATA_SIGNIF:     4.70 [sigma]
DATA_INTERVAL:   4.096 [sec]
GRB_DATE:        15020 TJD;   189 DOY;   09/07/08
GRB_TIME:        13098.46 SOD {03:38:18.46} UT
GRB_PHI:          21.00 [deg]
GRB_THETA:        66.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   413 (Gnd S/W Version number)
SUN_POSTN:       107.49d {+07h 09m 57s}  +22.46d {+22d 27' 50"}
SUN_DIST:         30.38 [deg]   Sun_angle= -2.2 [hr] (East of Sun)
MOON_POSTN:      296.41d {+19h 45m 37s}  -21.75d {-21d 44' 57"}
MOON_DIST:       157.63 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      204.22, 43.00 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      135.31,  8.32 [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/SWIFT NOTICE
NOTICE_DATE:     Wed 08 Jul 09 03:41:43 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     356776,   Seg_Num: 0
GRB_RA:          154.629d {+10h 18m 31s} (J2000),
                 154.762d {+10h 19m 03s} (current),
                 153.927d {+10h 15m 43s} (1950)
GRB_DEC:         +26.637d {+26d 38' 12"} (J2000),
                 +26.589d {+26d 35' 19"} (current),
                 +26.887d {+26d 53' 15"} (1950)
GRB_DATE:        15020 TJD;   189 DOY;   09/07/08
GRB_TIME:        13095.26 SOD {03:38:15.26} UT
TRIGGER_INDEX:   300
GRB_PHI:         -136.70 [deg]
GRB_THETA:        42.60 [deg]
DELTA_TIME:      64.00 [sec]
TRIGGER_DUR:     4.096 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     13.03 [sigma]
IMAGE_SIGNIF:    7.69 [sigma]
LC_URL:          sw00356776000msb.lc
SUN_POSTN:       107.49d {+07h 09m 58s}  +22.46d {+22d 27' 50"}
SUN_DIST:         42.97 [deg]   Sun_angle= -3.2 [hr] (East of Sun)
MOON_POSTN:      296.43d {+19h 45m 42s}  -21.74d {-21d 44' 37"}
MOON_DIST:       144.82 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      204.82, 56.03 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      146.74, 15.01 [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 = 152.05,20.05 [deg].

GCN Circular #9621
H. A. Krimm (CRESST/GSFC/USRA), S. D. Barthelmy (GSFC), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), C. B. Markwardt (CRESST/GSFC/UMD), K. L. Page (U Leicester), D. M. Palmer (LANL), A. Rowlinson (U Leicester), T. Sakamoto (NASA/UMBC), M. H. Siegel (PSU), M. A. Stark (PSU), T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU) report on behalf of the Swift Team:
At 03:38:15 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 090708 (trigger=356776). Swift did not slew because of Sun constraint. The BAT on-board calculated location is RA, Dec 154.629, +26.637 which is
```
   RA(J2000)  =  10h 18m 31s
   Dec(J2000) = +26d 38' 12"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows single peak with a duration of about 20 sec. The peak count rate was ~900 counts/sec (15-350 keV), at ~3 sec after the trigger.
Due to an observing constraint, Swift cannot slew to the BAT position, and it will not be observable until early October. There will thus be no XRT or UVOT data for this trigger.
Burst Advocate for this burst is H. A. Krimm (krimm AT milkyway.gsfc.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 Circular #9622
F. Yuan (U Mich), E.S. Rykoff (UCSB), H. Flewelling (IfA/Hawaii), T. Guver (U Arizona), S. B. Pandey (U Mich), W. Rujopakarn (Steward), report on behalf of the ROTSE collaboration:
ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 090708 (Swift trigger 356776; Krimm et al., GCN 9621), producing images beginning 7.4 s after the GCN notice time. An automated response took the first image at 03:39:04.5 UT, 49.2 s after the burst, under fair conditions. We took 10 5-sec, 10 20-sec and 10 60- sec exposures. These unfiltered images are calibrated relative to USNO A2.0 (R). Imaging is on going.
Comparison to the DSS (second epoch) reveals no new sources within the 3-sigma Swift/BAT error circle, for both single images and coadding into sets of 10. Individual images have limiting magnitudes ranging from 14.8-16.1; we set the following specific limits.
```
start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?
--------------------------------------------------------------------
03:39:04.5   03:39:09.5         5     15.0           49.2       N
03:39:04.5   03:40:11.6        67     16.6           49.2       Y
03:40:27.8   03:45:35.8       308     17.4          132.5       Y
```
GCN Circular #9623
D. M. Palmer (LANL), 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), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), 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+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 090708 (trigger #356776) (Krimm, et al., GCN Circ. 9621). The BAT ground-calculated position is RA, Dec = 154.632, 26.616 deg which is
```
   RA(J2000)  =  10h 18m 31.7s
   Dec(J2000) = +26d 36' 58.7"
```
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 27%.
The main pulse began at T-2 sec, peaked at ~T+4 sec and decayed by ~T+16 sec. There is a hint of some low-level emission out to ~T+100 sec. At T+160 sec, a pre-planned slew took the burst out of the BAT field of view. T90 (15-350 keV) is 15.0 +- 3.9 sec (estimated error including systematics).
The time-averaged spectrum from T-1.3 to T+17.7 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.78 +- 0.22. The fluence in the 15-150 keV band is 6.9 +- 1.0 x 10-7 erg/cm2. The 1-sec peak photon flux measured from T+3.37 sec in the 15-150 keV band is 1.3 +- 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/356776/BA/
GCN Circular #9624
J. Wren, W.T. Vestrand, P.R. Wozniak, H. Davis, B. Norman of Los Alamos National Laboratory report:
The RAPTOR telescope system responded to Swift trigger 356776 (Krimm et al., GCN 9621) under good observing conditions. A nearly full moon was above the horizon at the time of the observations, limiting sensitivity. Our narrow-field instruments began observing the location at 03:39:05.87 UTC, 50.62 s after the Swift trigger (6.9 s after receipt of GCN message). The data from our R-band filtered system was calibrated to the USNO-B1 catalog. These data show no new source within the BAT error circle (Palmer et al., GCN 9623) when compared to the DSS. We can put the following R-band (Cousins) limits on the emission:
```
t-mid(s)          exp(s)   mag    mag-err
[since trigger]
----------------------------------------------------
61.59             5.0      16.2   3 sigma limit
101.85           30.0      17.3   3 sigma limit
```
GCN Report 227.1
GCN_Report 227.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_227_1.pdf by H.A. Krimm at CRESST/GSFC/USRA titled: "Final Results on Swift GRB 090708"
GCN Circular #9631
S. McBreen (UCD/MPE) reports on behalf of the Fermi GBM Team:
"At 03:38:18.46 UT on 08 July 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 090708 (trigger 268717100 / 090708152) which was also detected by the Swift-BAT (Krimm et al. 2009, GCN 9621). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is 55 degrees.
The GBM light curve consists of one pulse with a duration of about 18 s (8-1000 keV). The time-averaged spectrum from T0-2.0 s to T0+16.2 s is adequately fit by a power law function with an exponential high energy cutoff. The power law index is -1.29 (+0.41/-0.34) and the cutoff energy, parameterized as Epeak, is 47.5 (+12.0/-9.5) keV (chi squared 359 for 361 d.o.f.).
The event fluence (8-1000 keV) in this time interval is about 4E-07 erg/cm^2. The 1-sec peak photon flux measured starting from T0+3.1 s in the 8-1000 keV band is 1.0 +/- 0.2 ph/s/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."

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Jochen Greiner, last update: 09-Jul-2009 [Disclaimer]