GRB081012

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: Sun Jan 19 21:46:17 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger331475
======================================================================

  Trigger: 00331475      Segment: 000

  BAT Trigger Time: 245509827.072   [s; MET]
      Trigger Stop: 245509829.12   [s; MET]
               UTC: 2008-10-12T13:10:23.902940    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 30.2174055107331   Dec: -17.6414535051542  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.78
     Image Trigger?:     NO
     Rate S/N Ratio:     17.606816861659  [ if not an image trigger ]
     Image S/N Ratio:    7.78

  Analysis Position:   [ source = BAT ]
    RA: 30.2174055107331   Dec: -17.6414535051542  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 30.1859159943555   Dec: -17.6295771472817  [deg; J2000]  
        { 02h 00m 44.6s , -17d 37' 46.5" }
         +/- 1.65649603543404 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.710847033993027 [arcmin] (formal 1-sigma fit error)
    SNR: 14.790717288235
 
  Angular difference between the analysis and refined position is 1.936452 arcmin
 
  Partial Coding Fraction: 0.2617188    [ including projection effects ]

  Duration
     T90: 28.972000002861 +/- 4.52475237177407
        Measured from: -21.0839999914169
                   to: 7.88800001144409     [s; relative to TRIGTIME]
     T50: 9.97200000286102 +/- 6.14550504651901
        Measured from: -7.0959999859333
                   to: 2.87600001692772     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.464000016450882     
                   to: 1.46400001645088     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -23.4600000083447     
                   to: 9.31999999284744     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.168633   0.535643   0.550150   0.232582
           0.050627   0.054299   0.050148   0.043944 [error]
 Peak      0.026922   0.042084   0.070951   0.016936
           0.009072   0.010147   0.010309   0.008341 [error]

     [ fluence units of on-axis counts / fully illuminated detector ] 

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   32.780  -23.460    9.320
T90    28.972  -21.084    7.888
T50     9.972   -7.096    2.876
Peak    1.000    0.464    1.464
 
 
====== 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      -0.958    -0.180      0.188       -           -               -         3.12e-03     -3.39e-04          3.36e-04      59.630   57
CPL     -0.412    -0.686      0.886      170.655      N/A           N/A         5.39e-03        N/A               N/A         58.050   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      -0.805     -0.330     0.359       -           -               -         1.04e-02     -2.16e-03          2.11e-03      55.290   57
CPL     -0.248     -0.841     2.021      189.456    -189.456      -189.456      1.80e-02     -9.35e-03          9.51e-02      54.860   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   7.89e-08  2.02e-07  4.17e-07  2.18e-06  1.12e-06  2.88e-06   erg/cm2
      90%_error_low -1.71e-08 -2.76e-08 -4.64e-08 -5.09e-07 -1.23e-07 -5.35e-07   erg/cm2
      90%_error_hi   1.85e-08  2.72e-08  4.61e-08  6.17e-07  1.24e-07  6.28e-07   erg/cm2
Peak flux       PL   2.22e-01  3.39e-01  3.88e-01  8.48e-01  1.20e+00  1.80e+00   ph/cm2/s
      90%_error_low -8.80e-02 -9.10e-02 -7.68e-02 -3.15e-01 -2.40e-01 -3.79e-01   ph/cm2/s
      90%_error_hi   1.04e-01  8.92e-02  7.62e-02  4.25e-01  2.41e-01  4.15e-01   ph/cm2/s
 
Fluence        CPL   6.83e-08  2.09e-07  4.42e-07  1.13e-06  1.10e-06  1.85e-06   erg/cm2
      90%_error_low -2.14e-08 -3.01e-08 -5.73e-08 -6.16e-07 -1.32e-07 -6.19e-07   erg/cm2
      90%_error_hi   2.30e-08  3.06e-08  5.87e-08  1.23e-06  1.30e-07  1.23e-06   erg/cm2
Peak flux      CPL   1.89e-01  3.45e-01  4.15e-01  5.15e-01  1.18e+00  1.46e+00   ph/cm2/s
      90%_error_low -1.11e-01 -9.81e-02 -9.74e-02 -5.15e-01 -2.48e-01 -4.59e-01   ph/cm2/s
      90%_error_hi   1.27e-01  9.90e-02  1.07e-01  4.48e-01  2.47e-01  5.32e-01   ph/cm2/s
 
======================================================================

Special notes of this burst

Image

Pre-slew 15.0-350.0 keV image (Event data)

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
   30.1859   -17.6296   0.0129    33.5823    69.7306         1.6088931     14.791 TRIG_00331475                 
 
Foreground time interval of the image:
-23.460   9.320 (delta_t =  32.780 [sec])
Background time interval of the image:
-263.771 -23.460 (delta_t = 240.311 [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

Bokeh Plot

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

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  -23.460 sec. to    9.320 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.957979     ( -0.180399   0.188244 )
Norm@50keV  : 3.12414E-03    ( -0.000339357   0.000336501 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          59.63 using 59 PHA bins.
# Reduced chi-squared =          1.046 for     57 degrees of freedom 
# Null hypothesis probability =   3.800906e-01
 
Photon flux (15-150 keV)    in 32.78 sec: 0.359022 ( -0.039413  0.039597 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.12447e-06 ( -1.23115e-07  1.23598e-07 ) ergs/cm2

Cutoff power-law model

Time interval is from  -23.460 sec. to    9.320 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.412156     ( -0.686354   0.885794 )
Epeak [keV] : 170.655      (   )
Norm@50keV  : 5.39144E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          58.05 using 59 PHA bins.
# Reduced chi-squared =          1.037 for     56 degrees of freedom 
# Null hypothesis probability =   3.995280e-01
 
Photon flux (15-150 keV)    in 32.78 sec: 0.350910 ( -0.04098  0.041075 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.09759e-06 ( -1.32116e-07  1.30274e-07 ) ergs/cm2

1-s peak spectrum fit

Power-law model

Time interval is from    0.464 sec. to    1.464 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.804901     ( -0.33017   0.35923 )
Norm@50keV  : 1.04434E-02    ( -0.00216126   0.00211217 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          55.29 using 59 PHA bins.
# Reduced chi-squared =         0.9700 for     57 degrees of freedom 
# Null hypothesis probability =   5.393908e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.20007 ( -0.239532  0.24095 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.21801e-07 ( -2.47031e-08  2.48415e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from    0.464 sec. to    1.464 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.248227     ( -0.841166   2.02143 )
Epeak [keV] : 189.456      ( -189.47 -189.47 )
Norm@50keV  : 1.79841E-02    ( -0.00935279   0.0950933 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          54.86 using 59 PHA bins.
# Reduced chi-squared =         0.9797 for     56 degrees of freedom 
# Null hypothesis probability =   5.180004e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.17788 ( -0.248002  0.24728 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.19391e-07 ( -2.69297e-08  2.58569e-08 ) ergs/cm2

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 28.972 sec.
Hardness ratio (energy fluence ratio) = 2.05915873601

S(15-50 keV) vs. S(50-150 keV) plot

S(15-50 keV)  = 2.8138333e-07
S(50-150 keV) = 8.43102e-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 = 2.300166331368824E-01, IMY = -6.228385430983757E-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:
-263.771410 -23.460000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 59.6711 -27.1443    2.7  10.2  124.5   0.5925   4.3 ------	UNKNOWN                       
321.6138 -72.5157    3.7  57.5  -26.9   3.2219   3.2 ------	UNKNOWN

Pre-slew background subtracted image of 15-350 keV band

Time interval of the image:
-23.460000 9.320000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 30.1859 -17.6296    0.8  33.6   69.7   1.6083  14.8 ------	UNKNOWN                       
 22.1163 -60.9765    2.2  34.1  -14.3   0.3300   5.3 ------	UNKNOWN

Post-slew image of 15-350 keV band

Time interval of the image:
301.828600 633.628600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
179.7047  52.6458    3.6  40.6 -172.9   0.9833   3.2 ------	UNKNOWN                       
212.2769  53.7468    4.0  57.4 -160.1   3.6691   2.9 ------	UNKNOWN                       
178.2131 -27.6402    3.9  50.7  -44.5   3.1873   3.0 ------	UNKNOWN

Analysis Summary

Notes:

Image

Pre-slew 15.0-350.0 keV image (Event data)

Light Curves

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

Notes:

Time averaged spectrum fit using the average DRM

Power-law model

Cutoff power-law model

1-s peak spectrum fit

Power-law model

Cutoff power-law model

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

S(15-50 keV) vs. S(50-150 keV) plot

Mask shadow pattern

Spacecraft aspect plot

Bright source in the pre-burst/pre-slew/post-slew images

Pre-burst image of 15-350 keV band

Pre-slew background subtracted image of 15-350 keV band

Post-slew image of 15-350 keV band

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