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 11:19:39 EST 2014
Host Name: batevent1
Current Working Dir: /local/data/batevent/batevent_reproc/trigger261880
======================================================================
Trigger: 00261880 Segment: 000
BAT Trigger Time: 194041680 [s; MET]
Trigger Stop: 194041744 [s; MET]
UTC: 2007-02-24T20:27:58.214180 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 178.989686201408 Dec: -13.3399298580834 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.5
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 7.5
Analysis Position: [ source = BAT ]
RA: 178.989686201408 Dec: -13.3399298580834 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 178.99720195201 Dec: -13.373545725744 [deg; J2000]
{ 11h 55m 59.3s , -13d 22' 24.8" }
+/- 2.29129570710923 [arcmin] (estimated 90% radius based on SNR)
+/- 0.910543767147948 [arcmin] (formal 1-sigma fit error)
SNR: 9.30500796835042
Angular difference between the analysis and refined position is 2.064121 arcmin
Partial Coding Fraction: 1 [ including projection effects ]
Duration
T90: 48 +/- 35.7770876399966
Measured from: -15
to: 33 [s; relative to TRIGTIME]
T50: 16 +/- 16
Measured from: -15
to: 1 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -7.5
to: -6.5 [s; relative to TRIGTIME]
Total Fluence
Measured from: -15
to: 49 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.361915 0.289511 0.112186 0.027142
0.037197 0.038685 0.033804 0.030114 [error]
Peak 0.009983 0.014453 -0.004225 0.000578
0.004767 0.004912 0.004304 0.003772 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 64.000 -15.000 49.000
T90 48.000 -15.000 33.000
T50 16.000 -15.000 1.000
Peak 1.000 -7.500 -6.500
====== 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 -2.289 -0.300 0.270 - - - 6.05e-04 -1.32e-04 1.30e-04 61.380 57
CPL -1.510 -0.827 1.509 22.576 -19.385 14.938 1.89e-03 -1.08e-03 1.57e-02 60.220 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 -2.157 -1.223 0.757 - - - 1.22e-03 -8.85e-04 8.57e-04 51.040 57
CPL 3.008 -3.196 -3.008 32.226 -7.286 8.711 3.04e+00 -3.04e+00 2.16e+05 46.190 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 1.04e-07 1.19e-07 9.75e-08 1.34e-07 3.70e-07 4.55e-07 erg/cm2
90%_error_low -1.72e-08 -1.81e-08 -2.76e-08 -6.04e-08 -6.45e-08 -1.02e-07 erg/cm2
90%_error_hi 1.74e-08 1.77e-08 2.99e-08 8.81e-08 6.76e-08 1.24e-07 erg/cm2
Peak flux PL 9.72e-02 6.37e-02 2.71e-02 1.59e-02 1.96e-01 2.04e-01 ph/cm2/s
90%_error_low -5.77e-02 -3.72e-02 -2.71e-02 -1.59e-02 -1.07e-01 -1.13e-01 ph/cm2/s
90%_error_hi 6.14e-02 3.69e-02 2.90e-02 4.31e-02 1.08e-01 1.17e-01 ph/cm2/s
Fluence CPL 1.02e-07 1.30e-07 N/A 1.11e-07 3.38e-07 3.81e-07 erg/cm2
90%_error_low -1.87e-08 N/A -2.76e-08 -9.20e-08 -6.58e-08 -1.08e-07 erg/cm2
90%_error_hi 1.83e-08 N/A 2.99e-08 4.35e-07 8.11e-08 1.89e-07 erg/cm2
Peak flux CPL 7.66e-02 1.24e-01 7.39e-03 4.66e-07 2.08e-01 2.09e-01 ph/cm2/s
90%_error_low -5.41e-02 -6.00e-02 -7.39e-03 -4.66e-07 -9.39e-02 -9.47e-02 ph/cm2/s
90%_error_hi 7.20e-02 6.08e-02 2.77e-02 1.60e-03 9.82e-02 9.73e-02 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 178.9972 -13.3735 0.0206 12.2877 -0.4991 0.7773800 9.305 TRIG_00261880 Foreground time interval of the image: -15.000 49.000 (delta_t = 64.000 [sec]) Background time interval of the image: -239.000 -15.000 (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 -15.000 sec. to 49.000 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -2.28896 ( -0.300418 0.270033 ) Norm@50keV : 6.05476E-04 ( -0.000131605 0.000129548 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 61.38 using 59 PHA bins. # Reduced chi-squared = 1.077 for 57 degrees of freedom # Null hypothesis probability = 3.219588e-01 Photon flux (15-150 keV) in 64 sec: 0.105178 ( -0.0140851 0.014092 ) ph/cm2/s Energy fluence (15-150 keV) : 3.69641e-07 ( -6.44864e-08 6.76493e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -15.000 sec. to 49.000 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.50955 ( -0.826979 1.50891 ) Epeak [keV] : 22.5761 ( -19.3854 14.9369 ) Norm@50keV : 1.89164E-03 ( -0.00108141 0.0157306 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 60.22 using 59 PHA bins. # Reduced chi-squared = 1.075 for 56 degrees of freedom # Null hypothesis probability = 3.255668e-01 Photon flux (15-150 keV) in 64 sec: 0.105400 ( -0.0141073 0.013968 ) ph/cm2/s Energy fluence (15-150 keV) : 3.38057e-07 ( -6.57619e-08 8.1113e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -7.500 sec. to -6.500 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -2.15739 ( -1.08746 0.89301 ) Norm@50keV : 1.21692E-03 ( -0.000872113 0.000869417 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 51.04 using 59 PHA bins. # Reduced chi-squared = 0.8954 for 57 degrees of freedom # Null hypothesis probability = 6.972080e-01 Photon flux (15-150 keV) in 1 sec: 0.195904 ( -0.107346 0.108216 ) ph/cm2/s Energy fluence (15-150 keV) : 1.10438e-08 ( -6.75101e-09 8.03276e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from -7.500 sec. to -6.500 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: 6.44076 ( -6.67693 -6.48918 ) Epeak [keV] : 32.0866 ( -7.14227 8.85436 ) Norm@50keV : 569.343 ( -661.529 215516 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 45.50 using 59 PHA bins. # Reduced chi-squared = 0.8126 for 56 degrees of freedom # Null hypothesis probability = 8.407542e-01 Photon flux (15-150 keV) in 1 sec: 0.207664 ( -0.09389 0.098156 ) ph/cm2/s Energy fluence (15-150 keV) : 9.86938e-09 ( -4.50326e-09 4.92681e-09 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 48.0 sec. Hardness ratio (energy fluence ratio) = 0.818540397333
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 2.235241e-07 S(50-150 keV) = 1.4612069e-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 = 2.178018704812982E-01, IMY = 1.897387479609091E-03
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: -239.000000 -15.000000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 179.6562 43.9069 2.9 45.0 173.7 1.1662 3.9 ------ UNKNOWN 197.6841 42.0144 2.2 46.0 -167.6 1.4909 5.2 ------ UNKNOWN 194.4151 14.4744 2.1 21.1 -144.1 0.9032 5.5 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -15.000000 49.000000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 154.5690 42.7021 1.9 49.5 149.6 1.9876 6.0 ------ UNKNOWN 176.8772 -11.6020 2.5 11.0 11.3 0.3707 4.7 ------ UNKNOWN 178.9972 -13.3736 1.2 12.3 -0.5 0.7776 9.4 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 129.100590 963.100000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 135.6042 -40.5968 5.1 46.6 -0.0 1.8253 2.2 4.3 Vela X-1 170.2892 -60.6424 5.7 47.7 -40.2 2.7231 2.0 1.4 Cen X-3 159.7756 0.1318 2.7 23.3 78.0 2.0529 4.3 ------ UNKNOWN 174.5395 -1.3048 2.9 12.8 113.9 1.4027 4.0 ------ UNKNOWN 145.3789 -33.3172 3.0 36.5 5.2 1.9049 3.8 ------ UNKNOWN 189.5516 1.6451 3.0 18.3 170.0 1.3517 3.8 ------ UNKNOWN 143.4278 -50.4883 2.4 47.0 -15.5 3.4858 4.7 ------ UNKNOWN 231.4595 15.4639 3.7 59.4 -163.2 11.2082 3.2 ------ UNKNOWN