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 02:38:09 EST 2014
Host Name: batevent1
Current Working Dir: /local/data/batevent/batevent_reproc/trigger310219
======================================================================
Trigger: 00310219 Segment: 000
BAT Trigger Time: 230909005.696 [s; MET]
Trigger Stop: 230909005.76 [s; MET]
UTC: 2008-04-26T13:23:22.949980 [includes UTCF correction]
Where From?: (*SHORT BURST*) TDRSS scaled map message
BAT
RA: 26.5741933788889 Dec: 69.4917855038209 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 8.32
Image Trigger?: NO
Rate S/N Ratio: 25.2586618806302 [ if not an image trigger ]
Image S/N Ratio: 8.32
Analysis Position: [ source = BAT ]
RA: 26.5741933788889 Dec: 69.4917855038209 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 26.5117622145044 Dec: 69.4686575708358 [deg; J2000]
{ 01h 46m 02.8s , +69d 28' 07.2" }
+/- 1.09380126954739 [arcmin] (estimated 90% radius based on SNR)
+/- 0.344493511880156 [arcmin] (formal 1-sigma fit error)
SNR: 26.7603667576436
Angular difference between the analysis and refined position is 1.910425 arcmin
Partial Coding Fraction: 0.4335938 [ including projection effects ]
Duration
T90: 1.7320000231266 +/- 0.383603980024552
Measured from: -0.0240000188350677
to: 1.70800000429153 [s; relative to TRIGTIME]
T50: 0.612000018358231 +/- 0.123223349376793
Measured from: 0.143999993801117
to: 0.756000012159348 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.112000018358231
to: 0.887999981641769 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.148000001907349
to: 2.08799999952316 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.238866 0.258778 0.150707 0.011165
0.013788 0.014487 0.011851 0.008832 [error]
Peak 0.176036 0.215705 0.121210 0.004363
0.010360 0.011422 0.009099 0.006175 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 2.236 -0.148 2.088
T90 1.732 -0.024 1.708
T50 0.612 0.144 0.756
Peak 1.000 -0.112 0.888
====== 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 -1.915 -0.120 0.117 - - - 1.82e-02 -1.33e-03 1.31e-03 49.870 57
CPL -1.747 -0.396 0.455 69.796 -50.958 -69.796 2.24e-02 N/A N/A 49.410 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 -1.911 -0.110 0.107 - - - 3.17e-02 -2.25e-03 2.23e-03 83.600 57
CPL -1.138 -0.455 0.508 50.547 -7.736 13.613 8.40e-02 -3.61e-02 7.44e-02 74.600 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 7.68e-08 1.10e-07 1.16e-07 2.29e-07 3.75e-07 5.32e-07 erg/cm2
90%_error_low -7.54e-09 -6.96e-09 -1.15e-08 -4.34e-08 -2.67e-08 -5.53e-08 erg/cm2
90%_error_hi 7.73e-09 6.96e-09 1.16e-08 4.97e-08 2.69e-08 5.98e-08 erg/cm2
Peak flux PL 1.94e+00 1.53e+00 8.16e-01 6.31e-01 4.58e+00 4.92e+00 ph/cm2/s
90%_error_low -1.82e-01 -9.63e-02 -7.45e-02 -1.05e-01 -2.91e-01 -3.06e-01 ph/cm2/s
90%_error_hi 1.86e-01 9.62e-02 7.45e-02 1.16e-01 2.91e-01 3.06e-01 ph/cm2/s
Fluence CPL 7.52e-08 1.12e-07 1.17e-07 1.73e-07 3.69e-07 4.77e-07 erg/cm2
90%_error_low -8.63e-09 -8.14e-09 -1.19e-08 -8.47e-08 -2.96e-08 -9.06e-08 erg/cm2
90%_error_hi 8.70e-09 8.81e-09 1.20e-08 6.87e-08 2.96e-08 7.88e-08 erg/cm2
Peak flux CPL 1.75e+00 1.67e+00 8.41e-01 2.69e-01 4.45e+00 4.53e+00 ph/cm2/s
90%_error_low -2.11e-01 -1.24e-01 -8.41e-02 -1.07e-01 -2.99e-01 -3.22e-01 ph/cm2/s
90%_error_hi 2.13e-01 1.27e-01 8.42e-02 1.69e-01 2.99e-01 3.34e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 26.5118 69.4687 0.0072 29.6888 -98.7296 0.7115681 26.760 TRIG_00310219 Foreground time interval of the image: -0.148 2.088 (delta_t = 2.236 [sec]) Background time interval of the image: -511.295 -489.616 (delta_t = 21.679 [sec]) -239.696 -0.148 (delta_t = 239.548 [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 -0.148 sec. to 2.088 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.91452 ( -0.120216 0.117233 ) Norm@50keV : 1.82122E-02 ( -0.00132707 0.00131045 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 49.87 using 59 PHA bins. # Reduced chi-squared = 0.8749 for 57 degrees of freedom # Null hypothesis probability = 7.372562e-01 Photon flux (15-150 keV) in 2.236 sec: 2.63006 ( -0.17104 0.17126 ) ph/cm2/s Energy fluence (15-150 keV) : 3.74517e-07 ( -2.66668e-08 2.68691e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.148 sec. to 2.088 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.74737 ( -0.396459 0.455013 ) Epeak [keV] : 69.7961 ( -50.958 -69.7961 ) Norm@50keV : 2.24113E-02 ( ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 49.41 using 59 PHA bins. # Reduced chi-squared = 0.8823 for 56 degrees of freedom # Null hypothesis probability = 7.208191e-01 Photon flux (15-150 keV) in 2.236 sec: 2.60954 ( -0.17838 0.17841 ) ph/cm2/s Energy fluence (15-150 keV) : 3.69369e-07 ( -2.95785e-08 2.96297e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.112 sec. to 0.888 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.91051 ( -0.109734 0.106964 ) Norm@50keV : 3.17351E-02 ( -0.00225328 0.00223101 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 83.60 using 59 PHA bins. # Reduced chi-squared = 1.467 for 57 degrees of freedom # Null hypothesis probability = 1.240227e-02 Photon flux (15-150 keV) in 1 sec: 4.57506 ( -0.29073 0.29098 ) ph/cm2/s Energy fluence (15-150 keV) : 2.91843e-07 ( -2.03366e-08 2.04771e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.112 sec. to 0.888 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.13769 ( -0.455234 0.508296 ) Epeak [keV] : 50.5474 ( -7.73588 13.613 ) Norm@50keV : 8.39868E-02 ( -0.0360594 0.0744064 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 74.60 using 59 PHA bins. # Reduced chi-squared = 1.332 for 56 degrees of freedom # Null hypothesis probability = 4.890885e-02 Photon flux (15-150 keV) in 1 sec: 4.45353 ( -0.29884 0.29903 ) ph/cm2/s Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 1.732 sec. Hardness ratio (energy fluence ratio) = 1.06108511964
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 1.8662569e-07 S(50-150 keV) = 1.8789102e-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 = -8.652968683331717E-02, IMY = 5.635253212181688E-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: -511.295400 -489.616200 -239.696000 -0.148000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.4197 35.3355 3.4 40.5 66.3 2.4066 3.4 1.9 Her X-1 299.5989 35.2059 0.5 41.1 9.0 7.3578 24.1 0.5 Cyg X-1 308.2994 40.8282 0.0 37.0 -3.5 -0.2711 -1.2 11.4 Cyg X-3 326.2742 38.4665 13.8 43.1 -23.2 0.2429 0.8 9.9 Cyg X-2 269.0112 31.0455 2.3 43.7 47.5 3.0846 5.1 ------ UNKNOWN 149.4602 44.2955 2.7 55.8 175.3 3.6296 4.3 ------ UNKNOWN 302.3640 35.6573 3.1 41.1 5.5 1.0034 3.8 ------ UNKNOWN 45.4018 69.6176 2.6 32.5 -110.3 1.2106 4.4 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -0.148000 2.088000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.4935 35.1853 9.0 40.6 66.2 -0.0668 -1.3 9.6 Her X-1 299.6018 35.0488 5.8 41.3 9.0 -0.0532 -2.0 9.2 Cyg X-1 307.9693 40.8647 6.5 36.9 -3.1 0.0394 1.8 8.3 Cyg X-3 326.1705 38.3231 149.3 43.2 -23.1 -0.0022 -0.1 0.1 Cyg X-2 244.3497 79.8299 1.9 8.4 -178.0 0.0870 6.1 ------ UNKNOWN 26.5117 69.4687 0.4 29.7 -98.7 0.7116 26.8 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 206.404590 962.365600 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 308.0334 40.9714 4.3 48.2 16.2 2.6308 2.7 3.7 Cyg X-3 326.2266 38.2899 16.0 44.2 -2.8 0.5206 0.7 3.2 Cyg X-2 156.9851 59.3347 2.5 46.4 131.8 7.5778 4.6 ------ UNKNOWN 73.4607 72.4915 2.7 15.1 156.6 1.4041 4.2 ------ UNKNOWN 113.1271 34.3081 4.7 57.0 179.0 7.3721 2.9 ------ UNKNOWN 112.8517 34.2641 5.7 56.9 179.2 7.0564 2.8 ------ UNKNOWN 7.3002 51.6128 2.6 20.0 -44.0 1.7434 4.5 ------ UNKNOWN 341.9810 20.0293 3.8 56.3 -28.2 6.5089 3.0 ------ UNKNOWN 71.5428 25.6683 4.2 51.0 -135.7 7.8885 2.8 ------ UNKNOWN