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 05:12:45 EST 2014
Host Name: batevent1
Current Working Dir: /local/data/batevent/batevent_reproc/trigger518626
======================================================================
Trigger: 00518626 Segment: 000
BAT Trigger Time: 354417637.312 [s; MET]
Trigger Stop: 354417637.824 [s; MET]
UTC: 2012-03-26T01:20:29.280140 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 273.92454494837 Dec: 69.2780331370331 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.23
Image Trigger?: NO
Rate S/N Ratio: 10.1488915650922 [ if not an image trigger ]
Image S/N Ratio: 7.23
Analysis Position: [ source = BAT ]
RA: 273.92454494837 Dec: 69.2780331370331 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 273.902617003907 Dec: 69.2480690336554 [deg; J2000]
{ 18h 15m 36.6s , +69d 14' 53.0" }
+/- 0.834675899999407 [arcmin] (estimated 90% radius based on SNR)
+/- 0.234094523747161 [arcmin] (formal 1-sigma fit error)
SNR: 39.3763723113846
Angular difference between the analysis and refined position is 1.857221 arcmin
Partial Coding Fraction: 0.9140625 [ including projection effects ]
Duration
T90: 69.4799999594688 +/- 8.17964784555291
Measured from: -55.2319999933243
to: 14.2479999661446 [s; relative to TRIGTIME]
T50: 5.21999990940094 +/- 0.43430867911566
Measured from: 1.84800004959106
to: 7.067999958992 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 3.58799999952316
to: 4.58799999952316 [s; relative to TRIGTIME]
Total Fluence
Measured from: -68.9839999675751
to: 21.5920000076294 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 1.849994 2.015343 1.037740 0.137300
0.050394 0.051525 0.044329 0.037140 [error]
Peak 0.189403 0.232733 0.121355 0.020770
0.007681 0.008159 0.006724 0.004514 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 90.576 -68.984 21.592
T90 69.480 -55.232 14.248
T50 5.220 1.848 7.068
Peak 1.000 3.588 4.588
====== 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: CPL)
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 -1.986 -0.071 0.070 - - - 3.20e-03 -1.26e-04 1.25e-04 62.180 57
CPL -1.400 -0.302 0.327 46.838 -6.559 7.895 6.53e-03 -1.97e-03 3.15e-03 50.460 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 -1.854 -0.082 0.081 - - - 3.37e-02 -1.64e-03 1.63e-03 62.260 57
CPL -1.234 -0.359 0.396 56.476 -7.860 18.203 7.25e-02 -2.56e-02 4.55e-02 53.040 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 5.85e-07 8.01e-07 8.09e-07 1.48e-06 2.67e-06 3.68e-06 erg/cm2
90%_error_low -3.45e-08 -2.82e-08 -4.42e-08 -1.65e-07 -1.00e-07 -2.04e-07 erg/cm2
90%_error_hi 3.52e-08 2.82e-08 4.44e-08 1.79e-07 1.01e-07 2.14e-07 erg/cm2
Peak flux PL 1.95e+00 1.59e+00 8.81e-01 7.16e-01 4.74e+00 5.14e+00 ph/cm2/s
90%_error_low -1.41e-01 -7.24e-02 -5.61e-02 -8.72e-02 -2.18e-01 -2.27e-01 ph/cm2/s
90%_error_hi 1.44e-01 7.23e-02 5.60e-02 9.44e-02 2.18e-01 2.27e-01 ph/cm2/s
Fluence CPL 5.33e-07 8.40e-07 8.03e-07 6.25e-07 2.52e-06 2.80e-06 erg/cm2
90%_error_low -4.23e-08 -3.45e-08 -4.87e-08 -2.05e-07 -1.24e-07 -2.46e-07 erg/cm2
90%_error_hi 4.30e-08 3.50e-08 4.83e-08 3.21e-07 1.25e-07 3.47e-07 erg/cm2
Peak flux CPL N/A N/A N/A N/A N/A N/A ph/cm2/s
90%_error_low -1.41e-01 -7.24e-02 -5.61e-02 -8.72e-02 -2.18e-01 -2.27e-01 ph/cm2/s
90%_error_hi 1.44e-01 7.23e-02 5.60e-02 9.44e-02 2.18e-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 273.9026 69.2481 0.0049 15.3125 -119.7098 4.4756009 39.376 TRIG_00518626 Foreground time interval of the image: -68.984 10.989 (delta_t = 79.973 [sec]) Background time interval of the image: -239.312 -68.984 (delta_t = 170.328 [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 -68.984 sec. to 21.592 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.98561 ( -0.070626 0.0697645 ) Norm@50keV : 3.19970E-03 ( -0.000125535 0.000124808 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 62.18 using 59 PHA bins. # Reduced chi-squared = 1.091 for 57 degrees of freedom # Null hypothesis probability = 2.970657e-01 Photon flux (15-150 keV) in 90.58 sec: 0.476841 ( -0.017751 0.01781 ) ph/cm2/s Energy fluence (15-150 keV) : 2.67129e-06 ( -1.00471e-07 1.01018e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -68.984 sec. to 21.592 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.39955 ( -0.302257 0.326623 ) Epeak [keV] : 46.8379 ( -6.55892 7.8951 ) Norm@50keV : 6.52736E-03 ( -0.00197346 0.00314676 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 50.46 using 59 PHA bins. # Reduced chi-squared = 0.9011 for 56 degrees of freedom # Null hypothesis probability = 6.837655e-01 Photon flux (15-150 keV) in 90.58 sec: 0.456771 ( -0.020172 0.020272 ) ph/cm2/s Energy fluence (15-150 keV) : 2.51711e-06 ( -1.24221e-07 1.25252e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 3.588 sec. to 4.588 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.85429 ( -0.0818493 0.080727 ) Norm@50keV : 3.36734E-02 ( -0.00164454 0.00163443 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 62.26 using 59 PHA bins. # Reduced chi-squared = 1.092 for 57 degrees of freedom # Null hypothesis probability = 2.944009e-01 Photon flux (15-150 keV) in 1 sec: 4.74170 ( -0.21783 0.21816 ) ph/cm2/s Energy fluence (15-150 keV) : 3.09656e-07 ( -1.51528e-08 1.52293e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 3.588 sec. to 4.588 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.23378 ( -0.359485 0.39614 ) Epeak [keV] : 56.4759 ( -7.85927 18.2031 ) Norm@50keV : 7.25104E-02 ( -0.0256064 0.0454769 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 53.04 using 59 PHA bins. # Reduced chi-squared = 0.9471 for 56 degrees of freedom # Null hypothesis probability = 5.877485e-01 Photon flux (15-150 keV) in 1 sec: ( ) ph/cm2/s Energy fluence (15-150 keV) : 2.92833e-07 ( -1.78284e-08 1.78947e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 69.48 sec. Hardness ratio (energy fluence ratio) = 0.956511080382
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 1.3731416e-06 S(50-150 keV) = 1.1439542e-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 = -1.356994435304406E-01, IMY = 2.378115082158468E-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: -239.312000 -68.984000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.4553 35.3400 382.6 22.3 21.9 0.0040 0.0 0.2 Her X-1 288.8122 10.9436 2.8 54.8 -18.2 1.8672 4.1 0.8 GRS 1915+105 299.6056 35.2256 2.2 39.0 -47.4 1.2705 5.3 1.6 Cyg X-1 308.0811 41.0057 2.4 39.2 -61.4 1.4859 4.8 3.4 Cyg X-3 246.2489 9.9980 2.5 47.7 35.6 2.1826 4.7 ------ UNKNOWN 148.5366 52.0614 3.4 53.6 160.8 2.4999 3.4 ------ UNKNOWN 193.0777 59.1035 2.6 29.6 147.0 0.7651 4.4 ------ UNKNOWN 104.6735 62.2107 2.8 57.4 -168.8 2.7539 4.2 ------ UNKNOWN 291.5502 55.9962 2.3 21.9 -74.2 0.7666 5.0 ------ UNKNOWN 319.5258 52.9212 3.1 37.6 -84.2 1.4525 3.7 ------ UNKNOWN 19.6637 69.0950 2.3 48.0 -128.9 2.9132 5.0 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -68.984000 10.988590 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.5056 35.4389 6.0 22.2 21.8 0.2131 1.9 6.2 Her X-1 288.6898 10.7723 14.9 54.9 -18.0 0.2678 0.8 12.2 GRS 1915+105 299.4284 35.0696 66.4 39.0 -47.0 0.0314 0.2 11.2 Cyg X-1 308.0573 40.9406 3.8 39.3 -61.3 0.7449 3.0 2.5 Cyg X-3 273.9026 69.2481 0.3 15.3 -119.7 4.4755 39.4 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 48.388600 332.788590 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.2715 35.3647 4.8 35.6 30.4 -0.6678 -2.4 9.2 Her X-1 288.7528 10.9315 4.2 59.1 -14.7 2.9814 2.7 2.8 GRS 1915+105 299.6108 35.1874 1.5 36.9 -33.8 2.2537 7.9 1.3 Cyg X-1 308.0602 40.9595 1.4 33.5 -47.9 2.3974 8.3 2.3 Cyg X-3 326.2774 38.3106 13.9 41.5 -67.4 0.6895 0.8 5.0 Cyg X-2 161.0203 57.5847 2.5 44.3 137.4 3.3465 4.5 ------ UNKNOWN 256.3599 27.0794 2.8 43.4 25.3 1.6972 4.2 ------ UNKNOWN 290.8042 43.4501 2.5 27.3 -25.1 0.9504 4.6 ------ UNKNOWN 10.4969 77.8488 3.3 25.1 -148.1 0.6904 3.5 ------ UNKNOWN