Analysis Summary
Notes:
- 1) No attempt has been made to eliminate the non-significant decimal places.
- 2) This batgrbproduct analysis is done using the HEASARC data.
- 3) This batgrbproduct analysis is using the flight position for the mask-weighting calculation.
======================================================================
BAT GRB EVENT DATA PROCESSING REPORT
Process Script Ver: batgrbproduct v2.46
Process Start Time: Mon Jan 20 00:50:39 EST 2014
Host Name: batevent1
Current Working Dir: /local/data/batevent/batevent_reproc/trigger315710
======================================================================
Trigger: 00315710 Segment: 000
BAT Trigger Time: 236692246.592 [s; MET]
Trigger Stop: 236692247.104 [s; MET]
UTC: 2008-07-02T11:50:43.681940 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 312.852867899564 Dec: 72.3078003909001 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 6.6
Image Trigger?: NO
Rate S/N Ratio: 13.0384048104053 [ if not an image trigger ]
Image S/N Ratio: 6.6
Analysis Position: [ source = BAT ]
RA: 312.852867899564 Dec: 72.3078003909001 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 313.061753110931 Dec: 72.2810323561386 [deg; J2000]
{ 20h 52m 14.8s , +72d 16' 51.7" }
+/- 3.00510932153163 [arcmin] (estimated 90% radius based on SNR)
+/- 1.08414045350372 [arcmin] (formal 1-sigma fit error)
SNR: 6.31627228279742
Angular difference between the analysis and refined position is 4.136195 arcmin
Partial Coding Fraction: 0.8125 [ including projection effects ]
Duration
T90: 0.512000024318695 +/- 0.181019344581714
Measured from: -0.0480000078678131
to: 0.464000016450882 [s; relative to TRIGTIME]
T50: 0.192000031471252 +/- 0.230755278125048
Measured from: 0.0799999833106995
to: 0.272000014781952 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.22800001502037
to: 0.77199998497963 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.0480000078678131
to: 0.527999997138977 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.013324 0.021166 0.020281 0.001564
0.004494 0.005028 0.004429 0.003926 [error]
Peak 0.015939 0.018017 0.020823 -0.000746
0.005784 0.006219 0.005631 0.005100 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 0.576 -0.048 0.528
T90 0.512 -0.048 0.464
T50 0.192 0.080 0.272
Peak 1.000 -0.228 0.772
====== Spectral Analysis Summary =====================================
Model : spectral model: simple power-law (PL) and cutoff power-law (CPL)
Ph_index : photon index: E^{Ph_index}
Ph_90err : 90% error of the photon index
Epeak : Epeak in keV
Epeak_90err: 90% error of Epeak
Norm : normalization at 50 keV in both the PL model and CPL model
Nomr_90err : 90% error of the normalization
chi2 : Chi-Squared
dof : degree of freedo
=== Time-averaged spectral analysis ===
(Best model with acceptable fit: PL)
Model Ph_index Ph_90err_low Ph_90err_hi Epeak Epeak_90err_low Epeak_90err_hi Norm Nomr_90err_low Norm_90err_hi chi2 dof
PL -1.237 -0.415 0.428 - - - 6.58e-03 -1.61e-03 1.61e-03 39.220 57
CPL -0.885 -0.751 2.007 157.491 -157.491 -157.491 9.98e-03 -4.94e-03 9.26e-02 39.060 56
=== 1-s peak spectral analysis ===
(Best model with acceptable fit: PL)
Model Ph_index Ph_90err_low Ph_90err_hi Epeak Epeak_90err_low Epeak_90err_hi Norm Nomr_90err_low Norm_90err_hi chi2 dof
PL -1.264 -0.514 0.518 - - - 3.92e-03 -1.18e-03 1.18e-03 38.500 57
CPL -0.078 -1.609 4.024 83.744 -54.286 -83.744 1.48e-02 -1.48e-02 8.65e-01 37.700 56
=== Fluence/Peak Flux Summary ===
Model Band1 Band2 Band3 Band4 Band5 Total
15-25 25-50 50-100 100-350 15-150 15-350 keV
Fluence PL 3.78e-09 8.17e-09 1.39e-08 5.40e-08 3.80e-08 7.98e-08 erg/cm2
90%_error_low -1.53e-09 -2.20e-09 -4.21e-09 -2.81e-08 -1.04e-08 -3.23e-08 erg/cm2
90%_error_hi 1.69e-09 2.14e-09 4.16e-09 4.49e-08 1.07e-08 4.66e-08 erg/cm2
Peak flux PL 1.29e-01 1.49e-01 1.24e-01 1.74e-01 4.65e-01 5.76e-01 ph/cm2/s
90%_error_low -6.17e-02 -4.97e-02 -4.54e-02 -1.02e-01 -1.40e-01 -1.80e-01 ph/cm2/s
90%_error_hi 7.15e-02 4.83e-02 4.46e-02 1.64e-01 1.40e-01 1.91e-01 ph/cm2/s
Fluence CPL 3.59e-09 8.52e-09 1.42e-08 3.08e-08 3.69e-08 5.71e-08 erg/cm2
90%_error_low -1.77e-09 -2.47e-09 -4.47e-09 -2.74e-08 -1.17e-08 -3.07e-08 erg/cm2
90%_error_hi 1.83e-09 2.82e-09 4.69e-09 3.20e-08 1.15e-08 3.48e-08 erg/cm2
Peak flux CPL 1.01e-01 1.63e-01 1.37e-01 6.00e-02 4.42e-01 4.61e-01 ph/cm2/s
90%_error_low -7.72e-02 -5.83e-02 -5.29e-02 -6.00e-02 -1.50e-01 -1.67e-01 ph/cm2/s
90%_error_hi 8.26e-02 6.22e-02 5.67e-02 1.58e-01 1.47e-01 2.18e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 313.0618 72.2810 0.0306 17.0897 -98.2310 0.0568554 6.316 TRIG_00315710 Foreground time interval of the image: -0.048 0.528 (delta_t = 0.576 [sec]) Background time interval of the image: -588.491 -508.521 (delta_t = 79.971 [sec]) -239.592 -0.048 (delta_t = 239.544 [sec])
Light Curves
Note: The mask-weighted lightcurves have units of either count/det or counts/sec/det, where a det is 0.4 x 0.4 = 0.16 sq cm.
Full-time range; 1 s binning
Other quick-look light curves:
- 64 ms binning (zoomed)
- 16 ms binning (zoomed)
- 8 ms binning (zoomed)
- 2 ms binning (zoomed)
- SN=5 or 10 s binning (full-time range)
- Raw light curve
Spectra
- 64 ms binning (zoomed)
- 16 ms binning (zoomed)
- 8 ms binning (zoomed)
- 2 ms binning (zoomed)
- SN=5 or 10 s binning (full-time range)
- Raw light curve
Spectra
Notes:
- 1) The fitting includes the systematic errors.
- 2) When the burst includes telescope slew time periods, the fitting uses an average response file made from multiple 5-s response files through out the slew time plus single time preiod for the non-slew times, and weighted by the total counts in the corresponding time period using addrmf. An average response file is needed becuase a spectral fit using the pre-slew DRM will introduce some errors in both a spectral shape and a normalization if the PHA file contains a lot of the slew/post-slew time interval.
- 3) For fits to more complicated models (e.g. a power-law over a cutoff power-law), the BAT team has decided to require a chi-square improvement of more than 6 for each extra dof.
Time averaged spectrum fit using the average DRM
Power-law model
Time interval is from -0.048 sec. to 0.528 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.23734 ( -0.414525 0.428408 ) Norm@50keV : 6.57717E-03 ( -0.0016105 0.00160559 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 39.22 using 59 PHA bins. # Reduced chi-squared = 0.6880 for 57 degrees of freedom # Null hypothesis probability = 9.652376e-01 Photon flux (15-150 keV) in 0.576 sec: 0.776335 ( -0.190717 0.191014 ) ph/cm2/s Energy fluence (15-150 keV) : 3.80463e-08 ( -1.04353e-08 1.07012e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.048 sec. to 0.528 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.885052 ( -0.750877 2.00748 ) Epeak [keV] : 157.491 ( -157.514 -157.514 ) Norm@50keV : 9.97674E-03 ( -0.00493993 0.0925726 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 39.06 using 59 PHA bins. # Reduced chi-squared = 0.6976 for 56 degrees of freedom # Null hypothesis probability = 9.584724e-01 Photon flux (15-150 keV) in 0.576 sec: 0.766990 ( -0.195918 0.193934 ) ph/cm2/s Energy fluence (15-150 keV) : 3.68971e-08 ( -1.1697e-08 1.15215e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.228 sec. to 0.772 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.26422 ( -0.514421 0.517979 ) Norm@50keV : 3.92175E-03 ( -0.00118322 0.00117747 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 38.50 using 59 PHA bins. # Reduced chi-squared = 0.6755 for 57 degrees of freedom # Null hypothesis probability = 9.713851e-01 Photon flux (15-150 keV) in 1 sec: 0.464935 ( -0.139736 0.140041 ) ph/cm2/s Energy fluence (15-150 keV) : 3.91075e-08 ( -1.31185e-08 1.35645e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.228 sec. to 0.772 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.0781828 ( -1.60956 4.02393 ) Epeak [keV] : 83.7438 ( -54.2809 -83.7384 ) Norm@50keV : 1.48315E-02 ( -0.0148354 0.865211 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 37.70 using 59 PHA bins. # Reduced chi-squared = 0.6733 for 56 degrees of freedom # Null hypothesis probability = 9.712201e-01 Photon flux (15-150 keV) in 1 sec: 0.442412 ( -0.149748 0.147087 ) ph/cm2/s Energy fluence (15-150 keV) : 3.60064e-08 ( -1.34827e-08 1.47873e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 0.512 sec. Hardness ratio (energy fluence ratio) = 1.69664198649
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 1.1953629e-08 S(50-150 keV) = 2.609332e-08
The dash-dotted line and the dashed line traces the fluences calculated from the Band function with Epeak = 15 and 150 keV, respectively. Both lines assume a canonical values of alpha = -1 and beta = -2.5.
Mask shadow pattern
IMX = -4.401498145025333E-02, IMY = 3.042762687946984E-01
Spacecraft aspect plot
Bright source in the pre-burst/pre-slew/post-slew images
Pre-burst image of 15-350 keV band
Time interval of the image: -588.491400 -508.520700 -239.592000 -0.048000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.3951 35.2957 4.1 36.3 140.2 -1.3635 -2.8 4.2 Her X-1 299.5890 35.2007 0.3 21.1 64.0 11.9573 42.9 0.1 Cyg X-1 308.1594 41.0191 1.6 16.5 40.0 1.7079 7.2 4.6 Cyg X-3 325.9932 38.3934 4.6 25.5 9.4 0.6410 2.5 9.4 Cyg X-2 335.1876 80.3834 3.7 26.6 -100.5 1.0933 3.1 ------ UNKNOWN 19.0586 42.8891 3.0 50.8 -44.5 5.9754 3.8 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -0.048000 0.528000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.6439 35.3129 10.6 36.1 139.9 -0.0155 -1.1 9.3 Her X-1 299.5024 35.1198 3.2 21.2 64.2 -0.0341 -3.6 6.5 Cyg X-1 308.3474 40.9610 37.4 16.6 39.6 0.0026 0.3 10.8 Cyg X-3 326.1733 38.5067 4.2 25.5 9.0 -0.0247 -2.7 11.1 Cyg X-2 220.7310 57.3583 2.3 40.2 -168.2 0.0590 5.1 ------ UNKNOWN 313.0621 72.2810 1.8 17.1 -98.2 0.0569 6.3 ------ UNKNOWN 55.2994 76.9486 2.5 41.1 -95.5 0.1497 4.6 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 50.508640 962.497500 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 299.5939 35.1981 0.6 37.7 79.5 34.4169 18.7 0.3 Cyg X-1 308.3101 41.0457 3.0 31.3 68.3 3.2294 3.8 10.6 Cyg X-3 326.2714 38.3546 5.1 34.6 43.0 1.7413 2.3 5.1 Cyg X-2 347.2803 31.4878 3.2 44.6 18.4 3.5439 3.6 ------ UNKNOWN