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 13 06:22:08 EST 2014
Host Name: batevent1
Current Working Dir: /local/data/batevent/batevent_reproc/trigger515976
======================================================================
Trigger: 00515976 Segment: 000
BAT Trigger Time: 351751204.416 [s; MET]
Trigger Stop: 351751208.512 [s; MET]
UTC: 2012-02-24T04:39:56.492380 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 40.9754640993993 Dec: -17.7926294691115 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.8
Image Trigger?: NO
Rate S/N Ratio: 9.8488578017961 [ if not an image trigger ]
Image S/N Ratio: 7.8
Analysis Position: [ source = BAT ]
RA: 40.9754640993993 Dec: -17.7926294691115 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 40.9352492353547 Dec: -17.7805838114318 [deg; J2000]
{ 02h 43m 44.5s , -17d 46' 50.1" }
+/- 2.36674659485247 [arcmin] (estimated 90% radius based on SNR)
+/- 1.09760698224247 [arcmin] (formal 1-sigma fit error)
SNR: 8.88414962720802
Angular difference between the analysis and refined position is 2.408552 arcmin
Partial Coding Fraction: 0.296875 [ including projection effects ]
Duration
T90: 7 +/- 2.23606797749979
Measured from: -1.41600000858307
to: 5.58399999141693 [s; relative to TRIGTIME]
T50: 4 +/- 1
Measured from: -0.416000008583069
to: 3.58399999141693 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.416000008583069
to: 0.583999991416931 [s; relative to TRIGTIME]
Total Fluence
Measured from: -1.41600000858307
to: 6.58399999141693 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.171260 0.184099 0.052321 0.032755
0.026116 0.026961 0.023974 0.022327 [error]
Peak 0.032861 0.039973 0.011694 0.009748
0.009204 0.009491 0.008499 0.007739 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 8.000 -1.416 6.584
T90 7.000 -1.416 5.584
T50 4.000 -0.416 3.584
Peak 1.000 -0.416 0.584
====== 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 -2.341 -0.415 0.356 - - - 2.81e-03 -8.12e-04 7.88e-04 45.140 57
CPL -1.955 N/A N/A 4.437 N/A N/A 4.87e-03 N/A N/A 44.990 56
=== 1-s peak spectral analysis ===
(Best model with acceptable fit: N/A)
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 -2.459 -0.847 0.578 - - - 4.43e-03 -4.43e-03 2.17e-03 55.680 57
CPL -1.853 N/A N/A 10.463 N/A N/A 9.88e-03 N/A N/A 55.620 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 6.36e-08 7.03e-08 5.55e-08 7.24e-08 2.16e-07 2.62e-07 erg/cm2
90%_error_low -1.38e-08 -1.41e-08 -2.06e-08 -4.10e-08 -4.83e-08 -7.34e-08 erg/cm2
90%_error_hi 1.40e-08 1.36e-08 2.27e-08 6.70e-08 5.10e-08 9.34e-08 erg/cm2
Peak flux PL 4.62e-01 2.66e-01 9.66e-02 4.64e-02 8.49e-01 8.71e-01 ph/cm2/s
90%_error_low -1.59e-01 -9.31e-02 -5.99e-02 -4.64e-02 -2.40e-01 -2.50e-01 ph/cm2/s
90%_error_hi 1.67e-01 8.39e-02 6.76e-02 7.77e-02 2.40e-01 2.52e-01 ph/cm2/s
Fluence CPL N/A N/A N/A N/A N/A N/A erg/cm2
90%_error_low -1.38e-08 -1.41e-08 -2.06e-08 -4.10e-08 -4.83e-08 -7.34e-08 erg/cm2
90%_error_hi 1.40e-08 1.36e-08 2.27e-08 6.70e-08 5.10e-08 9.34e-08 erg/cm2
Peak flux CPL N/A N/A N/A N/A N/A N/A ph/cm2/s
90%_error_low -1.59e-01 -9.31e-02 -5.99e-02 -4.64e-02 -2.40e-01 -2.50e-01 ph/cm2/s
90%_error_hi 1.67e-01 8.39e-02 6.76e-02 7.77e-02 2.40e-01 2.52e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 40.9352 -17.7806 0.0216 35.5738 -113.5179 0.4945639 8.884 TRIG_00515976 Foreground time interval of the image: -1.416 6.584 (delta_t = 8.000 [sec]) Background time interval of the image: -515.215 -496.569 (delta_t = 18.646 [sec]) -239.416 -1.416 (delta_t = 238.000 [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 -1.416 sec. to 6.584 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -2.34101 ( -0.41549 0.355647 ) Norm@50keV : 2.80748E-03 ( -0.000812369 0.000788379 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 45.14 using 59 PHA bins. # Reduced chi-squared = 0.7919 for 57 degrees of freedom # Null hypothesis probability = 8.718559e-01 Photon flux (15-150 keV) in 8 sec: 0.502142 ( -0.087172 0.08718 ) ph/cm2/s Energy fluence (15-150 keV) : 2.16382e-07 ( -4.82885e-08 5.09744e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.416 sec. to 6.584 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.95458 ( ) Epeak [keV] : 4.43745 ( ) Norm@50keV : 4.86667E-03 ( ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 44.99 using 59 PHA bins. # Reduced chi-squared = 0.8033 for 56 degrees of freedom # Null hypothesis probability = 8.540077e-01 Photon flux (15-150 keV) in 8 sec: 0.496925 ( -0.088234 0.086884 ) ph/cm2/s Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.416 sec. to 0.584 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -2.45904 ( -0.847412 0.578123 ) Norm@50keV : 4.43184E-03 ( -0.00443184 0.00217024 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 55.68 using 59 PHA bins. # Reduced chi-squared = 0.9769 for 57 degrees of freedom # Null hypothesis probability = 5.245289e-01 Photon flux (15-150 keV) in 1 sec: 0.849352 ( -0.239915 0.240138 ) ph/cm2/s Energy fluence (15-150 keV) : 4.38571e-08 ( -1.60856e-08 1.73949e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.416 sec. to 0.584 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.85349 ( ) Epeak [keV] : 10.4631 ( ) Norm@50keV : 9.88012E-03 ( ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 55.62 using 59 PHA bins. # Reduced chi-squared = 0.9933 for 56 degrees of freedom # Null hypothesis probability = 4.890036e-01 Photon flux (15-150 keV) in 1 sec: ( ) ph/cm2/s Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 7.0 sec. Hardness ratio (energy fluence ratio) = 0.789532594593
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 1.3394373e-07 S(50-150 keV) = 8.243919e-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 = -2.854052604166931E-01, IMY = 6.558275520128743E-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: -515.215400 -496.569100 -239.416000 -1.416000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 83.6336 22.0131 0.3 22.3 58.0 10.6004 44.0 0.1 Crab 75.2035 27.5277 3.2 23.1 33.5 0.7689 3.6 ------ UNKNOWN 68.3973 25.3142 2.4 19.9 18.0 0.9569 4.8 ------ UNKNOWN 81.4657 -51.9624 2.6 58.4 -171.8 5.4540 4.5 ------ UNKNOWN 43.5451 -41.1528 2.9 51.8 -138.6 4.5835 4.0 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -1.416000 6.584000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 83.4896 22.1314 6.8 22.3 57.6 -0.0564 -1.7 10.6 Crab 109.1579 0.4680 3.1 41.1 113.2 0.4157 3.6 ------ UNKNOWN 103.3959 -31.4524 2.6 49.8 157.7 0.4279 4.4 ------ UNKNOWN 40.9352 -17.7806 1.3 35.6 -113.5 0.4947 8.9 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 93.084600 962.645700 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 43.6596 -46.1520 2.2 28.5 178.2 2.3995 5.3 ------ UNKNOWN 33.7254 -74.6547 4.3 57.0 -175.6 5.6798 2.7 ------ UNKNOWN 21.4382 -24.7601 2.8 19.5 -112.3 1.8800 4.1 ------ UNKNOWN 16.0026 15.0251 2.8 41.0 -36.4 2.9549 4.2 ------ UNKNOWN 352.0843 -41.9545 3.4 48.0 -128.9 6.8738 3.4 ------ UNKNOWN