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: Wed May 6 17:38:36 EDT 2015
Host Name: bat1
Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger310785
======================================================================
Trigger: 00310785 Segment: 000
BAT Trigger Time: 231510376.192 [s; MET]
Trigger Stop: 231510376.256 [s; MET]
UTC: 2008-05-03T12:26:13.429140 [includes UTCF correction]
Where From?: (*SHORT BURST*) TDRSS scaled map message
BAT
RA: 286.617169964645 Dec: 68.7780078042036 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 8.79
Image Trigger?: NO
Rate S/N Ratio: 20.1990098767242 [ if not an image trigger ]
Image S/N Ratio: 8.79
Analysis Position: [ source = BAT ]
RA: 286.617169964645 Dec: 68.7780078042036 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 286.617 Dec: 68.778 [deg; J2000]
{ 19h 06m 28.1s , +68d 46' 40.8" }
+/- 2.40455375227 [arcmin] (estimated 90% radius based on SNR)
SNR: 8.6864077563
Angular difference between the analysis and refined position is 0.003721 arcmin
Partial Coding Fraction: 0.7578125 [ including projection effects ]
Duration
T90: 176 +/- 48
Measured from: -2.19200000166893
to: 173.807999998331 [s; relative to TRIGTIME]
T50: 64 +/- 16
Measured from: 13.8079999983311
to: 77.8079999983311 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 37.3079999983311
to: 38.3079999983311 [s; relative to TRIGTIME]
Total Fluence
Measured from: -2.19200000166893
to: 221.807999998331 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 1.346465 1.419820 0.852922 0.233665
0.073703 0.076213 0.067349 0.060187 [error]
Peak 0.022110 0.027603 0.032855 -0.001375
0.005174 0.005402 0.004822 0.004001 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 224.000 -2.192 221.808
T90 176.000 -2.192 173.808
T50 64.000 13.808 77.808
Peak 1.000 37.308 38.308
====== 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 -1.873 -0.122 0.119 - - - 9.89e-04 -7.23e-05 7.14e-05 40.340 57
CPL -1.679 -0.417 0.488 73.222 -57.326 -73.222 1.26e-03 -4.13e-04 1.06e-03 39.800 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 -1.405 -0.333 0.328 - - - 5.51e-03 -1.04e-03 1.03e-03 58.570 57
CPL -1.227 N/A N/A 226.611 N/A N/A 6.72e-03 N/A N/A 58.490 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 4.02e-07 5.88e-07 6.43e-07 1.32e-06 2.04e-06 2.95e-06 erg/cm2
90%_error_low -3.84e-08 -3.62e-08 -6.49e-08 -2.55e-07 -1.47e-07 -3.21e-07 erg/cm2
90%_error_hi 3.93e-08 3.62e-08 6.55e-08 2.95e-07 1.49e-07 3.52e-07 erg/cm2
Peak flux PL 2.07e-01 2.20e-01 1.66e-01 2.04e-01 6.72e-01 7.98e-01 ph/cm2/s
90%_error_low -6.37e-02 -4.39e-02 -3.99e-02 -8.58e-02 -1.24e-01 -1.52e-01 ph/cm2/s
90%_error_hi 6.94e-02 4.31e-02 3.91e-02 1.17e-01 1.24e-01 1.55e-01 ph/cm2/s
Fluence CPL 3.93e-07 6.01e-07 6.41e-07 9.23e-07 1.99e-06 2.56e-06 erg/cm2
90%_error_low -4.39e-08 -4.19e-08 -6.81e-08 -4.93e-07 -1.77e-07 -5.34e-07 erg/cm2
90%_error_hi 4.40e-08 4.69e-08 6.75e-08 6.77e-07 1.70e-07 5.21e-07 erg/cm2
Peak flux CPL 1.99e-01 2.24e-01 1.70e-01 1.66e-01 6.66e-01 7.59e-01 ph/cm2/s
90%_error_low -7.93e-02 -4.65e-02 -4.19e-02 -1.66e-01 -1.26e-01 -1.88e-01 ph/cm2/s
90%_error_hi 7.53e-02 4.94e-02 4.55e-02 1.07e-01 1.28e-01 1.90e-01 ph/cm2/s
======================================================================
Image
Pre-slew 25.0-100.0 keV image (Event data)
#RAcent DECcent POSerr Theta Phi Peak_Cts SNR Name 286.617 68.778 0.000 32.336 -6.729 0.026 8.686 TRIG_00310785 Image time interval: 0.000 to 0.064 [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 -2.192 sec. to 221.808 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.87271 ( -0.12159 0.118815 ) Norm@50keV : 9.88582E-04 ( -7.23395e-05 7.14028e-05 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 40.34 using 59 PHA bins. # Reduced chi-squared = 0.7077 for 57 degrees of freedom # Null hypothesis probability = 9.536366e-01 Photon flux (15-150 keV) in 224 sec: 0.140265 ( -0.008764 0.008772 ) ph/cm2/s Energy fluence (15-150 keV) : 2.03605e-06 ( -1.4737e-07 1.49287e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -2.192 sec. to 221.808 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.67943 ( -0.417134 0.488465 ) Epeak [keV] : 73.2221 ( -57.3271 -73.2228 ) Norm@50keV : 1.26439E-03 ( -0.000413436 0.00106474 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 39.80 using 59 PHA bins. # Reduced chi-squared = 0.7106 for 56 degrees of freedom # Null hypothesis probability = 9.500640e-01 Photon flux (15-150 keV) in 224 sec: 0.138801 ( -0.009334 0.009365 ) ph/cm2/s Energy fluence (15-150 keV) : 1.99195e-06 ( -1.76902e-07 1.69515e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 37.308 sec. to 38.308 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.40498 ( -0.332562 0.327633 ) Norm@50keV : 5.50960E-03 ( -0.00104355 0.00103161 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 58.57 using 59 PHA bins. # Reduced chi-squared = 1.028 for 57 degrees of freedom # Null hypothesis probability = 4.175866e-01 Photon flux (15-150 keV) in 1 sec: 0.671742 ( -0.124246 0.124454 ) ph/cm2/s Energy fluence (15-150 keV) : 5.319e-08 ( -1.12199e-08 1.14334e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 37.308 sec. to 38.308 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.22683 ( ) Epeak [keV] : 226.611 ( ) Norm@50keV : 6.71571E-03 ( ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 58.49 using 59 PHA bins. # Reduced chi-squared = 1.044 for 56 degrees of freedom # Null hypothesis probability = 3.841686e-01 Photon flux (15-150 keV) in 1 sec: 0.666477 ( -0.126244 0.127704 ) ph/cm2/s Energy fluence (15-150 keV) : 5.26054e-08 ( -1.17142e-08 1.18056e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 176.0 sec. Hardness ratio (energy fluence ratio) = 1.09226983436
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 9.90153e-07 S(50-150 keV) = 1.0459064e-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 = 0.628686079164, IMY = 0.0741715436521
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: -751.791400 -634.155000 -239.192000 -2.192000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 136.8662 19.4539 4.9 56.9 179.2 3.2774 2.4 ------ UNKNOWN 107.1371 56.0783 2.6 31.7 -128.5 1.1799 4.4 ------ UNKNOWN 332.2716 50.8877 4.8 56.3 -28.3 2.8038 2.4 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -2.192000 11.908590 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 255.9805 65.7414 2.5 27.4 15.6 0.1868 4.6 ------ UNKNOWN 286.6595 68.7730 2.1 32.3 -6.7 0.2189 5.4 ------ UNKNOWN 4.9828 71.6963 2.2 36.5 -50.8 0.2830 5.2 ------ UNKNOWN 72.1440 59.0365 2.2 39.1 -98.4 0.5789 5.2 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 64.108580 962.902000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.4698 35.2915 3.1 37.9 73.3 5.2145 3.7 3.1 Her X-1 299.5883 35.1989 0.2 34.3 9.4 31.2079 49.0 0.2 Cyg X-1 308.0662 40.9672 2.1 30.0 -5.1 3.1084 5.5 2.2 Cyg X-3 326.1119 38.3791 3.5 37.1 -27.4 2.2533 3.3 4.4 Cyg X-2 279.7490 58.4702 3.2 10.7 48.0 1.5419 3.6 ------ UNKNOWN 146.7658 50.7235 5.2 56.9 179.2 7.5359 2.2 ------ UNKNOWN 302.1740 61.9005 3.0 9.4 -22.3 1.7427 3.8 ------ UNKNOWN 314.5537 13.7849 2.4 57.8 -4.2 13.0364 4.8 ------ UNKNOWN 137.4894 51.8710 3.4 57.2 -173.8 9.9532 3.4 ------ UNKNOWN 319.0851 15.0524 3.0 57.5 -9.6 9.8358 3.8 ------ UNKNOWN 7.4905 50.1753 3.4 41.2 -77.8 8.5033 3.4 ------ UNKNOWN