Gamma-ray Burst 071117

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 17 Nov 07 14:50:26 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     296805,   Seg_Num: 0
GRB_RA:          335.020d {+22h 20m 05s} (J2000),
                 335.158d {+22h 20m 38s} (current),
                 334.139d {+22h 16m 33s} (1950)
GRB_DEC:         -63.441d {-63d 26' 27"} (J2000),
                 -63.401d {-63d 24' 04"} (current),
                 -63.693d {-63d 41' 32"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       13560 [cnts]    Image_Peak=2183 [image_cnts]
TRIGGER_DUR:     1.024 [sec]
TRIGGER_INDEX:   146     E_range: 25-100 keV
BKG_INTEN:       28880 [cnts]
BKG_TIME:        53389.63 SOD {14:49:49.63} UT
BKG_DUR:         8 [sec]
GRB_DATE:        14421 TJD;   321 DOY;   07/11/17
GRB_TIME:        53406.91 SOD {14:50:06.91} UT
GRB_PHI:         -25.07 [deg]
GRB_THETA:        39.40 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     152.61 [sigma]
IMAGE_SIGNIF:    25.57 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2 +28  +0  +0 -19  +1
SUN_POSTN:       232.51d {+15h 30m 04s}  -18.98d {-18d 59' 00"}
SUN_DIST:         78.57 [deg]   Sun_angle= -6.8 [hr] (East of Sun)
MOON_POSTN:      323.74d {+21h 34m 57s}  -15.39d {-15d 23' 08"}
MOON_DIST:        48.67 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      326.29,-46.23 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      307.46,-48.21 [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 = 231.31,-17.62 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 17 Nov 07 14:53:43 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     296805,   Seg_Num: 0
GRB_RA:          335.020d {+22h 20m 05s} (J2000),
                 335.158d {+22h 20m 38s} (current),
                 334.139d {+22h 16m 33s} (1950)
GRB_DEC:         -63.441d {-63d 26' 27"} (J2000),
                 -63.401d {-63d 24' 04"} (current),
                 -63.693d {-63d 41' 32"} (1950)
GRB_DATE:        14421 TJD;   321 DOY;   07/11/17
GRB_TIME:        53406.91 SOD {14:50:06.91} UT
TRIGGER_INDEX:   146
GRB_PHI:         -25.07 [deg]
GRB_THETA:        39.40 [deg]
DELTA_TIME:      32.00 [sec]
TRIGGER_DUR:     1.024 [sec]
SOLN_STATUS:     0x3
RATE_SIGNIF:     152.61 [sigma]
IMAGE_SIGNIF:    25.57 [sigma]
LC_URL:          sw00296805000msb.lc
SUN_POSTN:       232.52d {+15h 30m 04s}  -18.98d {-18d 59' 02"}
SUN_DIST:         78.57 [deg]   Sun_angle= -6.8 [hr] (East of Sun)
MOON_POSTN:      323.77d {+21h 35m 04s}  -15.37d {-15d 22' 25"}
MOON_DIST:        48.68 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      326.29,-46.23 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      307.46,-48.21 [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 = 231.31,-17.62 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 17 Nov 07 15:38:02 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     296805,   Seg_Num: 0
POINT_RA:        334.991d {+22h 19m 58s} (J2000)
POINT_DEC:       -63.396d {-63d 23' 46"} (J2000)
IMG_START_DATE:  14421 TJD;   321 DOY;   07/11/17
IMG_START_TIME:  56254.91 SOD {15:37:34.91} UT,   2848.0 [sec] since BAT Trigger Time
COUNTS:          7    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        1    Max_iter_allowed= 4
ERROR_CODE:      1
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        No source found in the image.

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 17 Nov 07 15:39:46 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     296805,   Seg_Num: 0
POINT_RA:        334.992d {+22h 19m 58s} (J2000)
POINT_DEC:       -63.396d {-63d 23' 44"} (J2000)
POINT_ROLL:      250.464d
IMG_START_DATE:  14421 TJD;   321 DOY;   07/11/17
IMG_START_TIME:  56259.28 SOD {15:37:39.28} UT,   2852.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.491
N_STARS:         42
X_OFFSET:        344 [pixels]
Y_OFFSET:        237 [pixels]
X_MAX:           1303 [pixels]
Y_MAX:           1196 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00296805000msufc2852.fits
SUN_POSTN:       232.55d {+15h 30m 12s}  -18.99d {-18d 59' 30"}
SUN_DIST:         78.55 [deg]   Sun_angle= -6.8 [hr] (East of Sun)
MOON_POSTN:      324.17d {+21h 36m 40s}  -15.20d {-15d 12' 12"}
MOON_DIST:        48.76 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      326.35,-46.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      307.48,-48.16 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 17 Nov 07 15:40:14 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     296805,   Seg_Num: 0
POINT_RA:        334.992d {+22h 19m 58s} (J2000)
POINT_DEC:       -63.396d {-63d 23' 44"} (J2000)
POINT_ROLL:      250.464d
IMG_START_DATE:  14421 TJD;   321 DOY;   07/11/17
IMG_START_TIME:  56259.28 SOD {15:37:39.28} UT,   2852.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.491
N_STARS:         42
X_OFFSET:        344 [pixels]
Y_OFFSET:        237 [pixels]
X_MAX:           1303 [pixels]
Y_MAX:           1196 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00296805000msufc2852.fits
SUN_POSTN:       232.55d {+15h 30m 12s}  -18.99d {-18d 59' 30"}
SUN_DIST:         78.55 [deg]   Sun_angle= -6.8 [hr] (East of Sun)
MOON_POSTN:      324.17d {+21h 36m 41s}  -15.20d {-15d 12' 06"}
MOON_DIST:        48.76 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      326.35,-46.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      307.48,-48.16 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 17 Nov 07 15:40:59 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     296805,   Seg_Num: 0
POINT_RA:        334.992d {+22h 19m 58s} (J2000)
POINT_DEC:       -63.396d {-63d 23' 44"} (J2000)
ROLL:            250.464d
IMG_START_DATE:  14421 TJD;   321 DOY;   07/11/17
IMG_START_TIME:  56259.28 SOD {15:37:39.28} UT,   2852.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     217006661
X_OFFSET:        663 [pixels]
Y_OFFSET:        556 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       823
Y_GRB_POS:       716
BINNING_INDEX:   1
IM_URL:          sw00296805000msuni2852.fits
SUN_POSTN:       232.55d {+15h 30m 12s}  -18.99d {-18d 59' 31"}
SUN_DIST:         78.55 [deg]   Sun_angle= -6.8 [hr] (East of Sun)
MOON_POSTN:      324.18d {+21h 36m 42s}  -15.20d {-15d 11' 56"}
MOON_DIST:        48.76 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      326.35,-46.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      307.48,-48.16 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 17 Nov 07 15:41:18 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     296805,   Seg_Num: 0
POINT_RA:        334.992d {+22h 19m 58s} (J2000)
POINT_DEC:       -63.396d {-63d 23' 44"} (J2000)
ROLL:            250.464d
IMG_START_DATE:  14421 TJD;   321 DOY;   07/11/17
IMG_START_TIME:  56259.28 SOD {15:37:39.28} UT,   2852.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     217006661
X_OFFSET:        663 [pixels]
Y_OFFSET:        556 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       823
Y_GRB_POS:       716
BINNING_INDEX:   1
IM_URL:          sw00296805000msuni2852.fits
SUN_POSTN:       232.55d {+15h 30m 12s}  -18.99d {-18d 59' 31"}
SUN_DIST:         78.55 [deg]   Sun_angle= -6.8 [hr] (East of Sun)
MOON_POSTN:      324.18d {+21h 36m 43s}  -15.20d {-15d 11' 52"}
MOON_DIST:        48.76 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      326.35,-46.25 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      307.48,-48.16 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_sources_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 17 Nov 07 15:59:13 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     296805,   Seg_Num: 0
GRB_RA:          335.0437d {+22h 20m 10.4s} (J2000),
                 335.1815d {+22h 20m 43.5s} (current),
                 334.1630d {+22h 16m 39.1s} (1950)
GRB_DEC:         -63.4423d {-63d 26' 32.2"} (J2000),
                 -63.4025d {-63d 24' 09.0"} (current),
                 -63.6938d {-63d 41' 37.6"} (1950)
GRB_ERROR:       4.3 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  14421 TJD;   321 DOY;   07/11/17
IMG_START_TIME:  56269.00 SOD {15:37:49.00} UT,   2862.1 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       232.56d {+15h 30m 15s}  -19.00d {-18d 59' 42"}
SUN_DIST:         78.55 [deg]   Sun_angle= -6.8 [hr] (East of Sun)
MOON_POSTN:      324.33d {+21h 37m 20s}  -15.13d {-15d 07' 53"}
MOON_DIST:        48.86 [deg]
MOON_ILLUM:      47 [%]
GAL_COORDS:      326.28,-46.24 [deg] galactic lon,lat of the burst
ECL_COORDS:      307.47,-48.21 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        TAM values, flux and significance fields are not valid  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper.php for details.

GCN Circular #7099
D. E. Vanden Berk (PSU) and T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift UVOT Team:
UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm) filter starting 2852 seconds after the BAT trigger. No 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 18.5 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 extinction of E(B-V) = 0.024.
GCN Circular #7098
T. N. Ukwatta (GSFC/GWU), W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU), J. R. Cummings (NASA/UMBC), G. Cusumano (INAF-IASFPA), N. Gehrels (NASA/GSFC), C. Guidorzi (Univ Bicocca&INAF-OAB), S. T. Holland (CRESST/USRA/GSFC), F. E. Marshall (NASA/GSFC), P. T. O'Brien (U Leicester), D. M. Palmer (LANL), P. Romano (Univ. Bicocca & INAF-OAB) and D. E. Vanden Berk (PSU) report on behalf of the Swift Team:
At 14:50:06 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 071117 (trigger=296805). Swift did not slew immediately to the burst due to an Earth constraint. The BAT on-board calculated location is RA, Dec 335.020, -63.441 which is
```
   RA(J2000) = 22h 20m 05s
   Dec(J2000) = -63d 26' 27"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single FRED peak with a duration of about 5 sec. The peak count rate was ~16000 counts/sec (15-350 keV), at ~0 sec after the trigger.
Because of an Earth limb constraint, the spacecraft did not slew promptly to the BAT position, and so there are no immediate XRT data products to analyze. NFI observations are expected at T+43 minutes, when it comes out of constraint.
Burst Advocate for this burst is T. N. Ukwatta (tilan.ukwatta AT gmail.com). 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 #7100
P. Romano, C. Guidorzi (Univ. Bicocca & INAF-OAB), A. Moretti (OAB) and T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift XRT Team:
Using prompt downlinked data (482.4 s), we find an X-ray source located at RA, Dec 335.0437, -63.4424 which is
```
   RA(J2000)  = 22 20 10.49
   Dec(J2000) = -63 26 32.6
```
with an uncertainty of 4.2 arcsec (radius, 90% containment). This is 37.2 arcseconds from the BAT position (Ukwatta et al., GCN Circ. 7098). Further analysis will be reported in a subsequent circular.
This circular is an official product of the Swift XRT Team.
GCN Circular #7102
H. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), C. Markwardt (GSFC/UMD), D. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU) (i.e. the Swift-BAT team):
Using the data set from T-119 to T+183 sec from recent telemetry downlinks, we report further analysis of BAT GRB 071117 (trigger #296805) (Ukwatta, et al., GCN Circ. 7098). The BAT ground-calculated position is RA, Dec = 335.026, -63.442 deg which is
```
   RA(J2000)  =  22h 20m 06.3s 
   Dec(J2000) = -63d 26' 31" 
```
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 53%.
The mask-weighted light curve shows a single FRED-like peak starting at ~T-0.5 sec, peaking at ~T+0.5 sec, and decaying away out to ~T+15 sec. T90 (15-350 keV) is 6.6 +- 1.8 sec (estimated error including systematics).
The time-averaged spectrum from T-0.4 to T+13.9 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.57 +- 0.06. The fluence in the 15-150 keV band is 2.4 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+0.02 sec in the 15-150 keV band is 11.3 +- 0.4 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
GCN Circular #7103
C. Guidorzi, P. Romano (Univ. Bicocca & INAF-OAB), A. Moretti (INAF-OAB) and T.N. Ukwatta (GSFC/GWU), report on behalf of the Swift-XRT team:
Swift XRT observed the GRB 071117 (trigger=296805, Ukwatta et al., GCN Circ. 7098) beginning 2.8 ks after the BAT trigger. In 4.4 ks of Photon Counting mode data spanning 2.8-14.7 ks after the trigger the position of the X-ray afterglow is RA,Dec =335.04579,-63.44278 degrees, which corresponds to
```
RA(J2000) =  22 20 10.99
Dec(J2000)= -63 26 34.0
```
with error circle of radius 3.8 arcsec (90%, including boresight uncertainties). This lies 3.6 arcsec from the previous XRT position (Romano et al., GCN Circ. 7100) and 32 arcsec from the BAT refined position (Krimm et al., GCN Circ 7102).
The X-ray light curve can be fit by a power law from T+2.8ks to T+14.7ks, with a decay index of 0.8 +/- 0.2.
The Photon Counting spectrum can modelled with an absorbed power-law, with a photon index of 2.2 +0.4/-0.3 and a total absorbing column of NH = (2.3 +0.9/-0.8) e21 cm-2. The Galactic value is 2.3e20 cm-2 in the direction of the burst. The 0.3-10 keV observed (unabsorbed) flux during this time is 3.0e-12 (5.0e-12) erg cm-2 s-1. Uncertainties are given at 90% confidence.
Assuming the source continues to decay with the same rate, we predict an XRT count rate of 1.3e-2 counts/s at T+24 hours, which corresponds to an observed 0.3-10keV flux of 7.8e-13 ergs cm-2 s-1.
This circular is an official product of the Swift-XRT team.
GCN Circular #7104
E. Berger (Princeton/OCIW) and S. Gonzalez (LCO) report:
"We observed the XRT error circle of GRB 071117 (GCNs 7102,7103) with the Swope 40-inch telescope at LCO starting on 2007 Nov. 18.07 UT (10.8 hours after the burst). In a single 300 sec exposure we do not detect any source within the XRT error circle to a limit of i>21 mag."
GCN Circular #7105
J. S. Bloom (UC Berkeley), on behalf of the Gemini GRB collaboration, reports:
"Imaging observations of the field of GRB 071117 (Ukwatta et al., GCN 7098) were autonomously queued for Gemini South as part of the program GS-2007B-Q-2 (PI = H.-W. Chen). Starting at 2007 Nov 18 00h24m UT, we obtained 5 x 180 sec images in r-band. Within the revised XRT error circle (Guidorzi et al. GCN 7103) we find one source (s1) at position:
s1: ra= 22:20:10.63 dec = -63:26:33.7 (J2000)
The uncertainty is 350 mas in each coordinate (relative to USNO B1.0). This source, s1, is roughly R=23.3 mag at the time of observation (based upon the USNO B.10 catalog magnitude of the source at 22:20:13.33 -63:26:32.9). There is another source straddling the 90% error circle, embedded in an apparent faint extension to the southeast at:
s2: ra= 22:20:10.42 dec = -63:26:35.5 (J2000)
Further observations will be required to determine if either of these sources are variable."
A finder may be obtained at: http://lyra.berkeley.edu/~jbloom/grb071117-gemini-ep1.ps.gz
This message may be cited.
GCN Report 106.1
GCN_Report 106.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_106_1.pdf by T.N. Ukwatta at GSFC/GWU titled: "Swift Observations of GRB 071117"
GCN Circular #7108
Klotz, A. (CESR-OMP), Boer M. (OHP), Atteia J.L. (LATT-OMP) report:
We imaged the field of GRB 071117 detected by SWIFT (trigger 296805) with the TAROT robotic telescope (D=25cm) located at the European Southern Observatory, La Silla observatory, Chile.
The observations started 9.5h after the GRB trigger (GRB occured during daytime). The elevation of the field decreased from from 54 degrees above horizon and weather conditions were excellents.
We co-added series of exposures taken in VRI filters from t_trig+9.5h to t_trig+11.3h. There is no OT detected in V and R bands. A source is detected in the I-band close to the limiting magnitude I~20 at a position compatible with XRT (Romano et al. GCNC 7100) and s1,s2 sources of Bloom (GCNC 7105). Due to the spatial sampling of TAROT (3.3arcsec/pixel) and to the very low signal to noise ratio we cannot discriminate between s1 and s2.
The source is also present in I-band in series 11.6-13.3 h and also in the series 13.7-15.8 h but the actual processing does not allow to say if the brightness decreases or not.
If we consider the I-band source TAROT is the same as the s1 source of Bloom (R=23.3), the corresponding (R-I)~3 is very high. The galactic extinction in R band is only 0.06 magnitude (estimated from D. Schlegel et al. 1998). As a consequence, we estimate that GRB 071117 is a good high redshift candidate (z>4.5).
This message may be cited.
GCN Circular #7110
J. S. Bloom (UC Berkeley), on behalf of the Gemini GRB collaboration, reports:
"Starting at 2007 Nov 19 00h19m, deep r-band observations of the field of GRB 071117 (Ukwatta et al., GCN 7098) were obtained with Gemini (see Bloom, GCN 7105 for information about the first epoch). Image differencing reveals that source s2 (just outside the formal XRT error circle) is fading, and is the likely optical afterglow of the GRB. To reiterate the position:
s2: ra= 22:20:10.42 dec = -63:26:35.5 (J2000)
The uncertainty is 350 mas in each coordinate (relative to USNO B1.0). Further is analysis is ongoing."
A finder may be obtained at: http://lyra.berkeley.edu/~jbloom/grb071117-diff.pdf
We thank the expert Gemini staff for carrying out this ToO.
This message may be cited.
GCN Circular #7112
S. R. Oates (MSSL-UCL) and T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift/UVOT team:
The Swift/UVOT observed the field of GRB 071117 (Ukwatta et al., GCN 7098) 48 minutes after the BAT trigger, once the Earth had come out of observing constraint. No new source is found in any of the UVOT observations in either single or co-added exposures at the position of s2 reported by Bloom et al. (GCN 7110) or within the XRT error circle (Guidorzi et al., GCN 7103).
The following 3-sigma upper limits were determined at the position of the Gemini detection (RA=22:20:10.42, DEC=-63:26:35.5, J2000 ):
```
Filter  Tstart   Tend    Exp       Magnitude
          (s)     (s)     (s)      (3-sigma UL)
-------------------------------------------------
v      2960     44497   1608        >21.2
white  2852     62512   1812        >22.9
b      3779     61600   3125        >22.5
u      3574     56599   3075        >22.2
uvw1   3369     55834   4154        >22.4
uvm2   3164     32613   2368        >21.8
uvw2   4190     62783   2227        >22.1
-------------------------------------------------
```
The values quoted above are not corrected for the expected Galactic extinction corresponding to a reddening of E(B-V) = 0.024 mag in the direction of the GRB (Schlegel et al. 1998).
GCN Circular #7114
S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P. Oleynik, M. Ulanov and T. Cline on behalf of the Konus-Wind and Konus-A teams report:
The GRB 071117 (Swift-BAT trigger #296805: Ukwatta et al., GCN 7098; Krimm et al., GCN 7102) triggered Konus-Wind at T0=53404.535 s UT (14:50:04.535). This burst also triggered Konus-A at T0=53408.587 s UT (14:50:08.587).
The Konus-Wind light curve shows a single FRED-like pulse with a duration of ~5 s. As observed by Konus-Wind the burst had a fluence of 5.84(-2.40, +0.30)x10^-6 erg/cm2, and a 64-ms peak flux measured from T0+0.160 s of 6.66(-2.95, +1.13)x10^-6 erg/cm2/s (both in the 20 keV - 1 MeV energy range). The burst shows strong hard-to-soft spectral evolution.
The time-integrated spectrum of the burst (from T0 to T0+8.448 s) is well 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 = 1.53(-0.16, +0.15) and Ep = 278 (-79, +236) keV (chi2 = 37.5/52 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.rssi.ru/LEA/GRBs/GRB071117_T53404/
GCN Circular #7115
C. Guidorzi, P. Romano (Univ. Bicocca & INAF-OAB), A. Moretti (INAF-OAB) and T.N. Ukwatta (GSFC/GWU), report on behalf of the Swift-XRT team:
We recalculated the XRT refined position of GRB 071117 (trigger=296805, Ukwatta et al., GCN Circ. 7098) by excluding the first orbit data, which were affected by the presence of a dead pixel column. In 8.3 ks of Photon Counting mode data spanning 8.7-28 ks after the trigger the position of the X-ray afterglow is RA,Dec =335.04336,-63.44278 degrees, which corresponds to
```
RA(J2000) =  22 20 10.41
Dec(J2000)= -63 26 34.0
```
with error circle of radius 3.8 arcsec (90%, including boresight uncertainties). The optical afterglow reported by Bloom et al. (GCN Circ. 7110) now lies 1.5" away from the new XRT centroid.
This circular is an official product of the Swift-XRT team.
GCN Circular #7117
P. Jakobsson (Univ. Hertfordshire), J.P.U. Fynbo, D. Malesani (DARK/NBI), N.R. Tanvir (Univ. Leicester), B. Milvang-Jensen (DARK/NBI), A.O. Jaunsen (Univ. Oslo), P.M. Vreeswijk, J. Hjorth (DARK/NBI), report on behalf of a larger collaboration:
We observed the field of GRB 071117 (Ukwatta et al., GCN 7098) with the ESO VLT, starting on 2007 Nov 18.005 UT (9.28 hr after the GRB). We clearly detect the two sources indicated by Bloom (GCNs 7105, 7110), including the afterglow s2. Source s1 appears extended in our images, while source s2 is indeed pointlike (seeing 0.85"). A faint nebulosity is apparent surrounding both objects.
A VLT spectrum was obtained with the FORS1 instrument starting on 2007 Nov 18.03 UT, placing both sources on the slit. Three exposures of 30 min each were secured. The afterglow spectrum shows a faint, blue continuum between 3700 to 9000 A, and a weak emission line is apparent at 8688 A. Interpreting this as [OII], we infer a redshift of z=1.331, which we consider as the likely redshift of the GRB. Interpreting the observed line as [OIII] or Halpha, we would expect to detect [OII] at 6466 or 4934 A, respectively, which we do not see. A more conservative upper limit to the GRB redshift comes from the nondetection of any dropout in the blue down to 3800 A, which implies z < 2.1.
The spectrum of s1 is very red, with no significant flux below 5000 A. A plot of the 2D spectrum and a finding chart showing the afterglow and the various XRT error circles is posted at:
https://grbtoo.dark-cosmology.dk/public/gcn-pages/grb-071117/.
We acknowledge excellent support from the ESO observing staff, in particular Stephane Brillant and Emanuela Pompei.
GCN Report 106.2
GCN_Report 106.2 has been posted: http://gcn.gsfc.nasa.gov/reports/report_106_2.pdf by T.N. Ukwatta at GSFC/GWU titled: "Final Swift Observations of GRB 071117"

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Jochen Greiner, last update: 21-Nov-2007 [Disclaimer]