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 09:32:02 EST 2014
Host Name: batevent1
Current Working Dir: /local/data/batevent/batevent_reproc/trigger279898
======================================================================
Trigger: 00279898 Segment: 000
BAT Trigger Time: 201375895.232 [s; MET]
Trigger Stop: 201375899.328 [s; MET]
UTC: 2007-05-20T17:44:53.264200 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 121.951513642403 Dec: 57.6167755712018 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.32
Image Trigger?: NO
Rate S/N Ratio: 10 [ if not an image trigger ]
Image S/N Ratio: 7.32
Analysis Position: [ source = BAT ]
RA: 121.951513642403 Dec: 57.6167755712018 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 121.884543601363 Dec: 57.6040422374475 [deg; J2000]
{ 08h 07m 32.3s , +57d 36' 14.6" }
+/- 2.05374278052933 [arcmin] (estimated 90% radius based on SNR)
+/- 0.827842339031581 [arcmin] (formal 1-sigma fit error)
SNR: 10.87987794157
Angular difference between the analysis and refined position is 2.284012 arcmin
Partial Coding Fraction: 0.59375 [ including projection effects ]
Duration
T90: 96 +/- 35.7770876399966
Measured from: -15.2319999933243
to: 80.7680000066757 [s; relative to TRIGTIME]
T50: 48 +/- 16
Measured from: 0.76800000667572
to: 48.7680000066757 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 8.26800000667572
to: 9.26800000667572 [s; relative to TRIGTIME]
Total Fluence
Measured from: -15.2319999933243
to: 96.7680000066757 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.338528 0.460883 0.520753 0.164677
0.055549 0.058019 0.051689 0.044368 [error]
Peak -0.000480 0.017660 0.012065 0.003589
0.005980 0.006183 0.005571 0.004629 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 112.000 -15.232 96.768
T90 96.000 -15.232 80.768
T50 48.000 0.768 48.768
Peak 1.000 8.268 9.268
====== 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 -1.130 -0.206 0.212 - - - 9.24e-04 -1.03e-04 1.02e-04 70.650 57
CPL -1.123 -0.210 0.212 9999.300 -9999.300 -9999.300 9.29e-04 -1.02e-04 5.54e-04 70.670 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 -0.871 -0.853 1.239 - - - 2.34e-03 -2.34e-03 1.23e-03 39.430 57
CPL -0.650 2.904 5.296 340.158 N/A N/A 2.97e-03 N/A N/A 39.420 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 9.36e-08 2.16e-07 3.95e-07 1.72e-06 1.07e-06 2.42e-06 erg/cm2
90%_error_low -2.12e-08 -2.97e-08 -5.06e-08 -4.66e-07 -1.28e-07 -4.97e-07 erg/cm2
90%_error_hi 2.28e-08 2.89e-08 4.97e-08 5.84e-07 1.29e-07 5.98e-07 erg/cm2
Peak flux PL 5.30e-02 7.77e-02 8.50e-02 1.74e-01 2.69e-01 3.90e-01 ph/cm2/s
90%_error_low -5.30e-02 -5.58e-02 -4.26e-02 -1.74e-01 -1.41e-01 -1.96e-01 ph/cm2/s
90%_error_hi 7.16e-02 5.39e-02 4.20e-02 3.26e-01 1.45e-01 2.47e-01 ph/cm2/s
Fluence CPL 9.35e-08 2.14e-07 3.88e-07 1.73e-06 1.08e-06 2.29e-06 erg/cm2
90%_error_low N/A -3.93e-08 -6.40e-08 -8.63e-07 -1.81e-07 -7.18e-07 erg/cm2
90%_error_hi N/A 4.12e-08 7.74e-08 5.78e-07 1.73e-07 7.11e-07 erg/cm2
Peak flux CPL 5.04e-02 7.91e-02 8.74e-02 1.36e-01 2.68e-01 3.53e-01 ph/cm2/s
90%_error_low -5.04e-02 -5.67e-02 -4.50e-02 -1.36e-01 -1.39e-01 -2.20e-01 ph/cm2/s
90%_error_hi 7.36e-02 6.90e-02 5.66e-02 2.18e-01 1.46e-01 2.37e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 121.8845 57.6040 0.0177 30.7140 -132.9350 0.9447114 10.880 TRIG_00279898 Foreground time interval of the image: -15.232 35.669 (delta_t = 50.901 [sec]) Background time interval of the image: -239.232 -15.232 (delta_t = 224.000 [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 -15.232 sec. to 96.768 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.12997 ( -0.20622 0.212101 ) Norm@50keV : 9.24477E-04 ( -0.000102547 0.00010226 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 70.65 using 59 PHA bins. # Reduced chi-squared = 1.239 for 57 degrees of freedom # Null hypothesis probability = 1.056422e-01 Photon flux (15-150 keV) in 112 sec: 0.107566 ( -0.0124632 0.012506 ) ph/cm2/s Energy fluence (15-150 keV) : 1.07253e-06 ( -1.28448e-07 1.29152e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -15.232 sec. to 96.768 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.12307 ( -0.209488 0.212088 ) Epeak [keV] : 9999.30 ( -9999.36 -9999.36 ) Norm@50keV : 9.29080E-04 ( -0.000101956 0.000553726 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 70.67 using 59 PHA bins. # Reduced chi-squared = 1.262 for 56 degrees of freedom # Null hypothesis probability = 8.967404e-02 Photon flux (15-150 keV) in 112 sec: 0.107541 ( -0.0124639 0.012504 ) ph/cm2/s Energy fluence (15-150 keV) : 1.07765e-06 ( -1.80908e-07 1.72776e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 8.268 sec. to 9.268 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.870843 ( -0.852867 1.23875 ) Norm@50keV : 2.34332E-03 ( -0.00234332 0.00122923 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 39.43 using 59 PHA bins. # Reduced chi-squared = 0.6917 for 57 degrees of freedom # Null hypothesis probability = 9.632290e-01 Photon flux (15-150 keV) in 1 sec: 0.268940 ( -0.140622 0.14533 ) ph/cm2/s Energy fluence (15-150 keV) : 2.66042e-08 ( -1.3311e-08 1.34714e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 8.268 sec. to 9.268 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -4.32574 ( 6.57997 8.9722 ) Epeak [keV] : 340.158 ( ) Norm@50keV : 2.02619E-11 ( ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 39.30 using 59 PHA bins. # Reduced chi-squared = 0.7017 for 56 degrees of freedom # Null hypothesis probability = 9.559061e-01 Photon flux (15-150 keV) in 1 sec: 0.267587 ( -0.138906 0.145531 ) ph/cm2/s Energy fluence (15-150 keV) : 2.63263e-08 ( -1.54758e-08 1.36811e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 96.0 sec. Hardness ratio (energy fluence ratio) = 1.82772169537
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 3.0945819e-07 S(50-150 keV) = 7.630813e-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 = -4.046736628681478E-01, IMY = 4.349471981261410E-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: -239.232000 -15.232000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 163.8851 23.0641 2.5 54.1 164.9 3.3149 4.7 ------ UNKNOWN 185.4765 52.5562 3.1 22.7 143.5 0.5592 3.7 ------ UNKNOWN 301.1099 57.9528 2.4 39.0 4.4 1.0452 4.8 ------ UNKNOWN 135.0757 57.6315 2.5 27.3 -145.7 0.7291 4.6 ------ UNKNOWN 14.6201 56.6865 2.8 48.3 -49.9 3.3428 4.2 ------ UNKNOWN 19.0011 57.7697 3.5 47.2 -53.1 2.4888 3.3 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -15.232000 35.668600 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 151.8699 69.7939 2.2 13.2 -140.8 0.3325 5.1 ------ UNKNOWN 121.8845 57.6040 1.1 30.7 -132.9 0.9447 10.9 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 86.868590 489.968590 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 75.5849 61.7247 3.1 23.2 -50.0 0.8626 3.8 ------ UNKNOWN