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 00:55:37 EST 2014
Host Name: batevent1
Current Working Dir: /local/data/batevent/batevent_reproc/trigger315615
======================================================================
Trigger: 00315615 Segment: 000
BAT Trigger Time: 236600020.544 [s; MET]
Trigger Stop: 236600021.568 [s; MET]
UTC: 2008-07-01T10:13:37.636600 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 45.8375449298875 Dec: 75.4918923999807 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 16.1
Image Trigger?: NO
Rate S/N Ratio: 26.153393661244 [ if not an image trigger ]
Image S/N Ratio: 16.1
Analysis Position: [ source = BAT ]
RA: 45.8375449298875 Dec: 75.4918923999807 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 45.9127869201079 Dec: 75.4795842537653 [deg; J2000]
{ 03h 03m 39.1s , +75d 28' 46.5" }
+/- 1.35916552399682 [arcmin] (estimated 90% radius based on SNR)
+/- 0.425668605946213 [arcmin] (formal 1-sigma fit error)
SNR: 19.6213691595353
Angular difference between the analysis and refined position is 1.351113 arcmin
Partial Coding Fraction: 0.5546875 [ including projection effects ]
Duration
T90: 17.8160000145435 +/- 6.71978603572693
Measured from: -2.07600000500679
to: 15.7400000095367 [s; relative to TRIGTIME]
T50: 4.73600000143051 +/- 1.37488909679171
Measured from: -0.571999996900558
to: 4.16400000452995 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.104000002145767
to: 0.895999997854233 [s; relative to TRIGTIME]
Total Fluence
Measured from: -2.72799998521805
to: 22.4600000083447 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.574259 0.555610 0.251320 0.066565
0.034911 0.036277 0.032957 0.031352 [error]
Peak 0.101926 0.108407 0.044157 0.009218
0.008349 0.008538 0.007413 0.006439 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 25.188 -2.728 22.460
T90 17.816 -2.076 15.740
T50 4.736 -0.572 4.164
Peak 1.000 -0.104 0.896
====== 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 -2.119 -0.159 0.153 - - - 3.16e-03 -3.30e-04 3.25e-04 53.690 57
CPL -1.646 -0.387 0.700 29.780 N/A N/A 6.02e-03 N/A N/A 51.880 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 -2.170 -0.183 0.173 - - - 1.43e-02 -1.84e-03 1.82e-03 58.330 57
CPL -0.851 -0.850 1.030 32.761 -11.352 6.860 9.21e-02 -9.21e-02 3.17e-01 50.740 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 1.82e-07 2.30e-07 2.12e-07 3.41e-07 7.41e-07 9.66e-07 erg/cm2
90%_error_low -1.95e-08 -1.79e-08 -3.03e-08 -8.76e-08 -6.83e-08 -1.24e-07 erg/cm2
90%_error_hi 2.00e-08 1.78e-08 3.12e-08 1.07e-07 6.98e-08 1.39e-07 erg/cm2
Peak flux PL 1.12e+00 7.62e-01 3.39e-01 2.08e-01 2.33e+00 2.43e+00 ph/cm2/s
90%_error_low -1.39e-01 -7.24e-02 -5.64e-02 -5.83e-02 -2.17e-01 -2.28e-01 ph/cm2/s
90%_error_hi 1.42e-01 7.22e-02 5.81e-02 7.13e-02 2.17e-01 2.28e-01 ph/cm2/s
Fluence CPL 1.76e-07 2.43e-07 2.03e-07 1.41e-07 7.00e-07 7.62e-07 erg/cm2
90%_error_low -2.17e-08 -2.32e-08 -3.70e-08 -9.16e-08 -8.08e-08 -1.28e-07 erg/cm2
90%_error_hi 2.17e-08 2.40e-08 3.48e-08 2.39e-07 8.56e-08 1.44e-07 erg/cm2
Peak flux CPL 1.03e+00 8.77e-01 2.98e-01 3.64e-02 2.24e+00 2.24e+00 ph/cm2/s
90%_error_low -1.56e-01 -1.01e-01 -7.78e-02 -3.64e-02 -2.19e-01 -2.22e-01 ph/cm2/s
90%_error_hi 1.57e-01 1.03e-01 7.35e-02 7.00e-02 2.21e-01 2.26e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 45.9128 75.4796 0.0098 27.1383 -68.0203 1.4262907 19.621 TRIG_00315615 Foreground time interval of the image: -2.728 22.460 (delta_t = 25.188 [sec]) Background time interval of the image: -485.243 -443.492 (delta_t = 41.751 [sec]) -239.544 -2.728 (delta_t = 236.816 [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 -2.728 sec. to 22.460 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -2.11949 ( -0.159437 0.152677 ) Norm@50keV : 3.15922E-03 ( -0.000330294 0.00032491 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 53.69 using 59 PHA bins. # Reduced chi-squared = 0.9419 for 57 degrees of freedom # Null hypothesis probability = 6.001044e-01 Photon flux (15-150 keV) in 25.19 sec: 0.501907 ( -0.038263 0.038275 ) ph/cm2/s Energy fluence (15-150 keV) : 7.40984e-07 ( -6.83044e-08 6.98055e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -2.728 sec. to 22.460 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.64559 ( -0.38676 0.699769 ) Epeak [keV] : 29.7802 ( ) Norm@50keV : 6.02330E-03 ( ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 51.88 using 59 PHA bins. # Reduced chi-squared = 0.9264 for 56 degrees of freedom # Null hypothesis probability = 6.314736e-01 Photon flux (15-150 keV) in 25.19 sec: 0.490773 ( -0.040564 0.040631 ) ph/cm2/s Energy fluence (15-150 keV) : 6.99839e-07 ( -8.07566e-08 8.56289e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.104 sec. to 0.896 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -2.17038 ( -0.182714 0.173087 ) Norm@50keV : 1.42676E-02 ( -0.00184292 0.00181589 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 58.33 using 59 PHA bins. # Reduced chi-squared = 1.023 for 57 degrees of freedom # Null hypothesis probability = 4.261152e-01 Photon flux (15-150 keV) in 1 sec: 2.32610 ( -0.21651 0.21652 ) ph/cm2/s Energy fluence (15-150 keV) : 1.33638e-07 ( -1.50365e-08 1.53736e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.104 sec. to 0.896 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.851116 ( -0.850288 1.02952 ) Epeak [keV] : 32.7611 ( -11.352 6.85983 ) Norm@50keV : 9.21156E-02 ( -0.0921125 0.316827 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 50.74 using 59 PHA bins. # Reduced chi-squared = 0.9061 for 56 degrees of freedom # Null hypothesis probability = 6.736613e-01 Photon flux (15-150 keV) in 1 sec: 2.23764 ( -0.21938 0.22067 ) ph/cm2/s Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 17.816 sec. Hardness ratio (energy fluence ratio) = 0.920555516246
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 4.127925e-07 S(50-150 keV) = 3.282063e-07
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 = 1.918433682149012E-01, IMY = 4.753133698941900E-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: -485.243400 -443.492000 -239.544000 -2.728000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.4913 35.2336 5.1 40.6 113.5 1.9299 2.3 6.7 Her X-1 299.6078 35.1972 0.7 41.2 56.3 10.8267 16.3 0.9 Cyg X-1 308.2852 40.8999 17.2 37.0 43.9 0.2685 0.7 8.5 Cyg X-3 325.9719 38.3015 18.2 43.2 24.6 -0.2807 -0.6 9.5 Cyg X-2 198.5852 57.1417 2.6 32.5 -171.8 0.9818 4.4 ------ UNKNOWN 172.9592 75.2812 2.5 23.3 -131.5 0.9824 4.6 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -2.728000 22.460000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.6193 35.3365 7.0 40.5 113.4 -0.3292 -1.6 7.9 Her X-1 299.7694 35.2514 7.4 41.1 56.1 -0.2881 -1.6 9.3 Cyg X-1 308.0567 40.9877 12.4 36.9 44.1 0.0901 0.9 3.2 Cyg X-3 326.0482 38.3620 8.3 43.2 24.5 0.1540 1.4 6.3 Cyg X-2 271.3869 43.4888 2.4 31.2 92.5 0.4318 4.9 ------ UNKNOWN 45.9128 75.4796 0.6 27.1 -68.0 1.4263 19.6 ------ UNKNOWN 117.2505 62.9190 2.1 41.7 -107.6 1.1481 5.4 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 633.856600 962.514100 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.4441 35.3163 5.8 34.2 -169.5 -0.6007 -2.0 1.7 Her X-1 268.2537 -1.5282 32.2 42.7 126.8 -0.3595 -0.4 8.2 SW J1753.5-0127 288.7991 10.9414 0.6 22.4 102.2 5.7405 18.1 0.3 GRS 1915+105 299.5958 35.2023 0.2 4.3 -48.9 13.5539 56.9 0.3 Cyg X-1 308.0827 40.9276 1.2 13.1 -50.6 2.4461 9.3 2.0 Cyg X-3 325.9780 38.2419 13.7 25.2 -28.1 0.2193 0.8 10.3 Cyg X-2 344.1726 9.8943 2.5 49.9 9.5 2.9540 4.6 ------ UNKNOWN 343.6535 14.7201 3.6 46.9 4.4 1.7682 3.2 ------ UNKNOWN 358.0725 36.4623 3.9 50.7 -29.0 2.0816 2.9 ------ UNKNOWN 330.8357 68.5713 3.1 41.3 -77.5 4.0724 3.7 ------ UNKNOWN