Gamma-ray Burst 110318A

(All information courtesy of the instrument teams.)

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 18 Mar 11 13:14:36 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     449542,   Seg_Num: 0
GRB_RA:          338.274d {+22h 33m 06s} (J2000),
                 338.424d {+22h 33m 42s} (current),
                 337.605d {+22h 30m 25s} (1950)
GRB_DEC:         -15.282d {-15d 16' 55"} (J2000),
                 -15.224d {-15d 13' 26"} (current),
                 -15.540d {-15d 32' 24"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       8046 [cnts]    Image_Peak=577 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   148     E_range: 25-100 keV
BKG_INTEN:       42028 [cnts]
BKG_TIME:        47641.23 SOD {13:14:01.23} UT
BKG_DUR:         8 [sec]
GRB_DATE:        15638 TJD;    77 DOY;   11/03/18
GRB_TIME:        47659.60 SOD {13:14:19.60} UT
GRB_PHI:         -120.61 [deg]
GRB_THETA:        38.15 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     41.19 [sigma]
IMAGE_SIGNIF:    16.94 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  +5 -100  +0 -91  +0 
SUN_POSTN:       357.79d {+23h 51m 09s}   -0.96d {-00d 57' 28"}
SUN_DIST:         23.85 [deg]   Sun_angle= 1.3 [hr] (West of Sun)
MOON_POSTN:      160.27d {+10h 41m 06s}   +3.21d {+03d 12' 25"}
MOON_DIST:       167.85 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:       46.05,-55.79 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      334.24, -5.73 [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 = 11.29,-20.23 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Fri 18 Mar 11 13:14:31 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      46
TRIGGER_NUM:     322146858
GRB_RA:          327.600d {+21h 50m 24s} (J2000),
                 327.767d {+21h 51m 04s} (current),
                 326.853d {+21h 47m 25s} (1950)
GRB_DEC:         -35.067d {-35d 03' 59"} (J2000),
                 -35.014d {-35d 00' 49"} (current),
                 -35.301d {-35d 18' 01"} (1950)
GRB_ERROR:       30.03 [deg radius, statistical plus systematic]
GRB_INTEN:       48 [cnts/sec]
DATA_SIGNIF:     4.80 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        15638 TJD;    77 DOY;   11/03/18
GRB_TIME:        47656.70 SOD {13:14:16.70} UT
GRB_PHI:          48.00 [deg]
GRB_THETA:        70.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      2.52
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      44%  Solar Flare
2nd_MOST_LIKELY:  32%  GRB
DETECTORS:       0,1,1, 0,0,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       357.79d {+23h 51m 09s}   -0.96d {-00d 57' 28"}
SUN_DIST:         44.06 [deg]   Sun_angle= 2.0 [hr] (West of Sun)
MOON_POSTN:      160.27d {+10h 41m 05s}   +3.21d {+03d 12' 26"}
MOON_DIST:       146.14 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:        9.78,-50.78 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      317.61,-20.65 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 21.78,17.48 [deg].

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Fri 18 Mar 11 13:15:00 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      67
TRIGGER_NUM:     322146858
GRB_RA:          336.530d {+22h 26m 07s} (J2000),
                 336.682d {+22h 26m 44s} (current),
                 335.852d {+22h 23m 25s} (1950)
GRB_DEC:         -18.170d {-18d 10' 11"} (J2000),
                 -18.113d {-18d 06' 45"} (current),
                 -18.425d {-18d 25' 28"} (1950)
GRB_ERROR:       2.28 [deg radius, statistical only]
DATA_SIGNIF:     46.00 [sigma]
DATA_INTERVAL:   4.096 [sec]
GRB_DATE:        15638 TJD;    77 DOY;   11/03/18
GRB_TIME:        47656.70 SOD {13:14:16.70} UT
GRB_PHI:          28.00 [deg]
GRB_THETA:        70.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   413 (Gnd S/W Version number)
SUN_POSTN:       357.79d {+23h 51m 09s}   -0.96d {-00d 57' 28"}
SUN_DIST:         26.91 [deg]   Sun_angle= 1.4 [hr] (West of Sun)
MOON_POSTN:      160.28d {+10h 41m 06s}   +3.21d {+03d 12' 19"}
MOON_DIST:       164.68 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:       40.17,-55.43 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      331.60, -7.79 [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/FERMI NOTICE
NOTICE_DATE:     Fri 18 Mar 11 13:14:42 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      57
TRIGGER_NUM:     322146858
GRB_RA:          343.700d {+22h 54m 48s} (J2000),
                 343.853d {+22h 55m 25s} (current),
                 343.017d {+22h 52m 04s} (1950)
GRB_DEC:         -27.817d {-27d 48' 59"} (J2000),
                 -27.757d {-27d 45' 23"} (current),
                 -28.083d {-28d 05' 00"} (1950)
GRB_ERROR:       5.85 [deg radius, statistical plus systematic]
GRB_INTEN:       693 [cnts/sec]
DATA_SIGNIF:     32.90 [sigma]
INTEG_TIME:      1.024 [sec]
GRB_DATE:        15638 TJD;    77 DOY;   11/03/18
GRB_TIME:        47656.70 SOD {13:14:16.70} UT
GRB_PHI:          35.00 [deg]
GRB_THETA:        60.00 [deg]
DATA_TIME_SCALE: 1.0240 [sec]
HARD_RATIO:      0.61
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      96%  GRB
2nd_MOST_LIKELY:   3%  Generic Transient
DETECTORS:       0,1,1, 0,0,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       357.79d {+23h 51m 09s}   -0.96d {-00d 57' 28"}
SUN_DIST:         29.94 [deg]   Sun_angle= 0.9 [hr] (West of Sun)
MOON_POSTN:      160.27d {+10h 41m 06s}   +3.21d {+03d 12' 23"}
MOON_DIST:       155.21 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:       24.60,-64.18 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      334.04,-19.23 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 21.78,17.48 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 18 Mar 11 13:18:26 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     449542,   Seg_Num: 0
GRB_RA:          338.274d {+22h 33m 06s} (J2000),
                 338.424d {+22h 33m 42s} (current),
                 337.605d {+22h 30m 25s} (1950)
GRB_DEC:         -15.282d {-15d 16' 55"} (J2000),
                 -15.224d {-15d 13' 26"} (current),
                 -15.540d {-15d 32' 24"} (1950)
GRB_DATE:        15638 TJD;    77 DOY;   11/03/18
GRB_TIME:        47659.60 SOD {13:14:19.60} UT
TRIGGER_INDEX:   148
GRB_PHI:         -120.61 [deg]
GRB_THETA:        38.15 [deg]
DELTA_TIME:      -76.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     41.19 [sigma]
IMAGE_SIGNIF:    16.94 [sigma]
LC_URL:          sw00449542000msb.lc
SUN_POSTN:       357.79d {+23h 51m 10s}   -0.96d {-00d 57' 24"}
SUN_DIST:         23.86 [deg]   Sun_angle= 1.3 [hr] (West of Sun)
MOON_POSTN:      160.31d {+10h 41m 14s}   +3.19d {+03d 11' 27"}
MOON_DIST:       167.82 [deg]
MOON_ILLUM:      98 [%]
GAL_COORDS:       46.05,-55.79 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      334.24, -5.73 [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 = 11.29,-20.23 [deg].

GCN Circular #11798
B. Sbarufatti (INAF-OAB/IASFPA), S. D. Barthelmy (GSFC), M. M. Chester (PSU), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), J. M. Gelbord (PSU), C. Gronwall (PSU), C. Guidorzi (U Ferrara), S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU), R. Margutti (INAF-OAB), A. Melandri (INAF-OAB), K. L. Page (U Leicester), P. Romano (INAF-IASFPA), C. J. Saxton (UCL-MSSL), M. H. Siegel (PSU), E. Sonbas (GSFC/USRA/Adiyaman Univ.) and C. A. Swenson (PSU) report on behalf of the Swift Team:
At 13:14:19 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 110318A (trigger=449542). Swift did not slew to the burst because of the Sun observing constraint. The BAT on-board calculated location is RA, Dec 338.274, -15.282, which is
```
   RA(J2000)  =  22h 33m 06s
   Dec(J2000) = -15d 16' 55"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows two main peaks with a duration of about 20 sec. The peak count rate was ~7000 counts/sec (15-350 keV), at ~2 sec after the trigger.
Due to a Sun observing constraint, Swift cannot slew to the BAT position until 05:00 UT on 2011 April 11. There will thus be no XRT or UVOT data for this trigger before this time.
Burst Advocate for this burst is B. Sbarufatti (boris.sbarufatti AT brera.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 #11802
S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), B. Sbarufatti (INAF-OAB/IASFPA), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team):
Using the data set from T-114 to T+595 sec from the recent telemetry downlink, we report further analysis of BAT GRB 110318A (trigger #449542) (Sbarufatti, et al., GCN Circ. 11798). The BAT ground-calculated position is RA, Dec = 338.292, -15.278 deg, which is
```
   RA(J2000)  =  22h 33m 10.0s 
   Dec(J2000) = -15d 16' 40.9" 
```
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 27%.
The mask-weighted light curve shows a small precursor peak between T-8 and T-2 sec. The main peak starts at ~T-1 sec, peaks at ~T+1 sec, and ends at ~T+15 sec. T90 (15-350 keV) is 16.0 +- 1.7 sec (estimated error including systematics).
The time-averaged spectrum from T-13.0 to T+10.6 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 1.05 +- 0.23, and Epeak of 94.3 +- 23.7 keV (chi squared 43.1 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 4.9 +- 0.2 x 10^-6 erg/cm2 and the 1-sec peak flux measured from T+1.95 sec in the 15-150 keV band is 8.0 +- 0.5 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.58 +- 0.05 (chi squared 59.4 for 57 d.o.f.). 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/449542/BA/
GCN Circular #11805
G. Fitzpatrick (UCD) reports on behalf of the Fermi GBM Team:
"At 13:14:16.70 UT on 18th March 2011, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 110318 (trigger 322146858 / 110318552),=A0 =A0which was also detected by the Swift/BAT (Barthelmy et al. 2011,=A0 GCN 11798). The GBM on-ground location is consistent with the Swift=A0 position.
The angle from the Fermi LAT boresight is 70 degrees.
The GBM light curve consists of single peak with a duration (T90) of about 12 s (50-300 keV).=A0 The time-averaged spectrum from T0-1 s to T0+10 s is =A0 fit well with =A0a power law function with an exponential high-energy cutoff. =A0The power law index is -0.86 +/- 0.04 and the cutoff energy, parameterized as Epeak, is 114.70 +/- 3.72 keV
A Band function fits the spectrum equally well with Epeak=3D 107.00 +/- 5= .18 =A0keV, alpha =3D-0.80 +/- 0.05, and beta =3D -2.74 +/- 0.25.
The event fluence (10-1000 keV) in this time interval is=A0 (8.05 +/- 0.15)E-6 erg/cm^2. The 1-sec peak photon flux measured=A0 starting from T0-1 s in the 8-1000 keV band=A0 is 10.97 +/- 0.29 ph/s/cm^2.
The spectral analysis results presented above are preliminary;=A0 final results will be published in the GBM GRB Catalog."

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Jochen Greiner, last update: 18-Mar-2011 [Disclaimer]