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 03:40:30 EST 2014
Host Name: batevent1
Current Working Dir: /local/data/batevent/batevent_reproc/trigger306778
======================================================================
Trigger: 00306778 Segment: 000
BAT Trigger Time: 227622359.616 [s; MET]
Trigger Stop: 227622360.64 [s; MET]
UTC: 2008-03-19T12:25:56.961660 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 258.973352489113 Dec: 55.4098844023449 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 15.1
Image Trigger?: NO
Rate S/N Ratio: 69.3613725354393 [ if not an image trigger ]
Image S/N Ratio: 15.1
Analysis Position: [ source = BAT ]
RA: 258.973352489113 Dec: 55.4098844023449 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 259.008096885045 Dec: 55.3913388801278 [deg; J2000]
{ 17h 16m 01.9s , +55d 23' 28.8" }
+/- 0.916906688220536 [arcmin] (estimated 90% radius based on SNR)
+/- 0.273196054266063 [arcmin] (formal 1-sigma fit error)
SNR: 34.4302049307086
Angular difference between the analysis and refined position is 1.624630 arcmin
Partial Coding Fraction: 0.3046875 [ including projection effects ]
Duration
T90: 29.5519999861717 +/- 9.41457083506473
Measured from: 0.212000012397766
to: 29.7639999985695 [s; relative to TRIGTIME]
T50: 7.45600000023842 +/- 0.45291942449091
Measured from: 1.95600000023842
to: 9.41200000047684 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.127999991178513
to: 1.12799999117851 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.328000009059906
to: 43.4200000166893 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 1.062880 1.879763 1.685047 0.497519
0.056512 0.061847 0.058308 0.052195 [error]
Peak 0.122295 0.212427 0.233555 0.079877
0.010521 0.013101 0.013873 0.011627 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 43.748 -0.328 43.420
T90 29.552 0.212 29.764
T50 7.456 1.956 9.412
Peak 1.000 0.128 1.128
====== 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 -1.285 -0.068 0.068 - - - 8.10e-03 -3.02e-04 3.02e-04 48.770 57
CPL -1.018 -0.271 0.285 201.645 -76.535 4411.335 1.08e-02 -2.40e-03 3.70e-03 45.870 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 -1.067 -0.107 0.108 - - - 4.40e-02 -2.75e-03 2.75e-03 40.650 57
CPL -0.906 -0.214 0.436 380.265 -380.265 -380.265 5.23e-02 -1.05e-02 2.97e-02 40.200 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 3.70e-07 7.75e-07 1.27e-06 4.72e-06 3.51e-06 7.14e-06 erg/cm2
90%_error_low -2.71e-08 -3.38e-08 -5.71e-08 -4.66e-07 -1.43e-07 -5.01e-07 erg/cm2
90%_error_hi 2.79e-08 3.37e-08 5.70e-08 5.02e-07 1.43e-07 5.30e-07 erg/cm2
Peak flux PL 1.20e+00 1.56e+00 1.49e+00 2.52e+00 5.09e+00 6.77e+00 ph/cm2/s
90%_error_low -1.43e-01 -1.16e-01 -1.06e-01 -3.64e-01 -3.23e-01 -4.67e-01 ph/cm2/s
90%_error_hi 1.49e-01 1.15e-01 1.06e-01 4.00e-01 3.23e-01 4.76e-01 ph/cm2/s
Fluence CPL 3.48e-07 7.90e-07 1.30e-06 3.27e-06 3.45e-06 5.71e-06 erg/cm2
90%_error_low -3.41e-08 -3.73e-08 -6.48e-08 -9.63e-07 -1.57e-07 -9.63e-07 erg/cm2
90%_error_hi 3.49e-08 3.77e-08 6.55e-08 1.36e-06 1.56e-07 1.35e-06 erg/cm2
Peak flux CPL 5.82e-01 4.45e-01 2.38e-01 2.22e-01 1.35e+00 1.53e+00 ph/cm2/s
90%_error_low -1.27e-01 -1.66e-01 -6.08e-02 -1.93e-02 -4.87e-01 -4.87e-01 ph/cm2/s
90%_error_hi 1.87e-01 1.09e-01 3.68e-02 1.48e-02 3.07e-01 2.27e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 259.0081 55.3913 0.0056 33.6705 -101.4636 5.3084307 34.430 TRIG_00306778 Foreground time interval of the image: -0.328 43.420 (delta_t = 43.748 [sec]) Background time interval of the image: -132.915 -0.328 (delta_t = 132.587 [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 -0.328 sec. to 43.420 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.28538 ( -0.0680927 0.0683079 ) Norm@50keV : 8.09523E-03 ( -0.000302179 0.000302175 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 48.77 using 59 PHA bins. # Reduced chi-squared = 0.8556 for 57 degrees of freedom # Null hypothesis probability = 7.728952e-01 Photon flux (15-150 keV) in 43.75 sec: 0.963239 ( -0.037976 0.038041 ) ph/cm2/s Energy fluence (15-150 keV) : 3.51284e-06 ( -1.42851e-07 1.43264e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.328 sec. to 43.420 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.0185 ( -0.270552 0.284828 ) Epeak [keV] : 201.645 ( -76.5348 4411.34 ) Norm@50keV : 1.07585E-02 ( -0.00239631 0.00369611 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 45.87 using 59 PHA bins. # Reduced chi-squared = 0.8191 for 56 degrees of freedom # Null hypothesis probability = 8.309642e-01 Photon flux (15-150 keV) in 43.75 sec: 0.948807 ( -0.040486 0.040535 ) ph/cm2/s Energy fluence (15-150 keV) : 3.45277e-06 ( -1.56689e-07 1.5574e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.128 sec. to 1.128 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.06733 ( -0.107177 0.107926 ) Norm@50keV : 4.39965E-02 ( -0.00274632 0.00274566 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 40.65 using 59 PHA bins. # Reduced chi-squared = 0.7132 for 57 degrees of freedom # Null hypothesis probability = 9.499147e-01 Photon flux (15-150 keV) in 1 sec: 5.08836 ( -0.32261 0.32277 ) ph/cm2/s Energy fluence (15-150 keV) : 4.64954e-07 ( -3.26493e-08 3.2806e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.128 sec. to 1.128 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.906133 ( -0.21407 0.436374 ) Epeak [keV] : 380.265 ( -380.266 -380.266 ) Norm@50keV : 5.22550E-02 ( -0.0104771 0.0296523 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 40.20 using 59 PHA bins. # Reduced chi-squared = 0.7178 for 56 degrees of freedom # Null hypothesis probability = 9.449950e-01 Photon flux (15-150 keV) in 1 sec: 1.35382 ( -0.486639 0.3071 ) ph/cm2/s Energy fluence (15-150 keV) : 4.61636e-07 ( -3.40928e-08 3.38941e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 29.552 sec. Hardness ratio (energy fluence ratio) = 1.64108011465
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 1.1454112e-06 S(50-150 keV) = 2.367468e-06
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 = -1.323988251153645E-01, IMY = 6.528828242920284E-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: -132.915400 -0.328000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.3603 35.3884 12.1 29.4 -63.0 -0.1471 -0.9 5.5 Her X-1 203.1634 -3.7668 2.3 42.4 58.4 2.1083 5.0 ------ UNKNOWN 229.8173 -11.0839 2.3 48.7 20.6 1.6145 5.1 ------ UNKNOWN 162.0736 62.8832 2.3 42.8 -177.5 0.8080 5.0 ------ UNKNOWN 266.3436 10.1180 3.5 50.9 -35.4 1.2787 3.3 ------ UNKNOWN 271.0396 31.9011 3.1 43.7 -64.2 1.8640 3.7 ------ UNKNOWN 273.7099 67.1019 3.4 43.8 -116.1 1.8213 3.4 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -0.328000 43.420000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.4272 35.4760 11.9 29.4 -63.2 -0.1104 -1.0 8.2 Her X-1 259.0081 55.3914 0.3 33.7 -101.5 5.3077 34.4 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 208.084600 962.484000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.6691 35.2234 0.0 20.4 18.7 -0.2099 -0.7 12.6 Her X-1 268.3265 -1.4124 17.0 57.3 -2.5 1.2936 0.7 3.5 SW J1753.5-0127 288.6751 10.9458 5.2 50.2 -30.7 -1.9915 -2.2 7.3 GRS 1915+105 299.5648 35.2019 0.6 34.2 -62.4 11.5491 20.9 1.3 Cyg X-1 308.0971 40.9527 2.6 34.9 -77.9 3.7244 4.4 0.6 Cyg X-3 106.1979 68.7630 2.9 54.2 176.8 5.3589 4.0 ------ UNKNOWN 252.9535 87.8005 2.3 32.4 -171.8 1.8294 5.0 ------ UNKNOWN 293.4878 59.8891 2.4 18.8 -109.4 1.6589 4.8 ------ UNKNOWN 288.1969 13.5267 3.0 47.6 -31.4 3.0803 3.9 ------ UNKNOWN 310.0225 38.1816 3.5 37.9 -76.2 3.3158 3.3 ------ UNKNOWN 298.8044 14.8660 2.0 50.8 -44.5 11.7438 5.8 ------ UNKNOWN