GRB081029: Summary Image Light curves Spectra Distribution Others

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 21:10:58 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger332931
======================================================================

  Trigger: 00332931      Segment: 000

  BAT Trigger Time: 246937440   [s; MET]
      Trigger Stop: 246937504   [s; MET]
               UTC: 2008-10-29T01:43:56.788020    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 346.703787157334   Dec: -68.159638914543  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    11.49
     Image Trigger?:     YES
     Rate S/N Ratio:     0  [ if not an image trigger ]
     Image S/N Ratio:    11.49

  Analysis Position:   [ source = BAT ]
    RA: 346.703787157334   Dec: -68.159638914543  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 346.761947245779   Dec: -68.1701997611752  [deg; J2000]  
        { 23h 07m 02.9s , -68d 10' 12.7" }
         +/- 2.09465946373624 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.925258207746063 [arcmin] (formal 1-sigma fit error)
    SNR: 10.577545717326
 
  Angular difference between the analysis and refined position is 1.444329 arcmin
 
  Partial Coding Fraction: 0.5859375    [ including projection effects ]

  Duration
     T90: 275.104000031948 +/- 48.9548761810702
        Measured from: -24.0640000104904
                   to: 251.040000021458     [s; relative to TRIGTIME]
     T50: 106.511999994516 +/- 37.2252639035916
        Measured from: 15.5480000078678
                   to: 122.060000002384     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 20.5719999969006     
                   to: 21.5719999969006     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -36.2560000121593     
                   to: 270.243999987841     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.656352   1.262595   0.918684   0.320510
           0.109706   0.114528   0.102133   0.090530 [error]
 Peak      0.019444   0.017710   0.009729   0.008874
           0.006339   0.006703   0.005947   0.005177 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  306.500  -36.256  270.244
T90   275.104  -24.064  251.040
T50   106.512   15.548  122.060
Peak    1.000   20.572   21.572
 
 
====== 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      -1.407    -0.181      0.182       -           -               -         7.25e-04     -7.64e-05          7.62e-05      67.290   57
CPL     -1.101    -0.458      0.792      149.667    -149.667      -149.667      1.03e-03     -4.07e-04          1.48e-03      66.720   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      -1.739     -0.712     0.632       -           -               -         3.32e-03     -1.44e-03          1.37e-03      44.010   57
CPL     -0.447     -1.732     5.125       53.023     -53.023       -53.023      1.74e-02     -1.74e-02          1.63e+01      43.390   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   2.60e-07  5.06e-07  7.63e-07  2.50e-06  2.14e-06  4.02e-06   erg/cm2
      90%_error_low -4.76e-08 -5.81e-08 -1.00e-07 -6.42e-07 -2.46e-07 -7.23e-07   erg/cm2
      90%_error_hi   5.01e-08  5.75e-08  9.92e-08  7.80e-07  2.47e-07  8.36e-07   erg/cm2
Peak flux       PL   1.72e-01  1.50e-01  9.00e-02  8.12e-02  4.47e-01  4.93e-01   ph/cm2/s
      90%_error_low -8.91e-02 -5.69e-02 -4.74e-02 -8.12e-02 -1.68e-01 -1.87e-01   ph/cm2/s
      90%_error_hi   1.00e-01  5.67e-02  4.84e-02  1.14e-01  1.69e-01  1.89e-01   ph/cm2/s
 
Fluence        CPL   2.47e-07  5.23e-07  7.81e-07  1.58e-06  2.10e-06  3.13e-06   erg/cm2
      90%_error_low -5.61e-08 -6.80e-08 -1.08e-07 -9.68e-07 -2.72e-07 -9.99e-07   erg/cm2
      90%_error_hi   5.73e-08  7.11e-08  1.11e-07  1.67e-06  2.68e-07  1.19e-06   erg/cm2
Peak flux      CPL   1.48e-01  1.73e-01  9.22e-02  2.07e-02  4.30e-01  4.34e-01   ph/cm2/s
      90%_error_low     N/A   -7.32e-02 -9.22e-02 -2.07e-02 -1.71e-01 -1.75e-01   ph/cm2/s
      90%_error_hi      N/A    8.33e-02  5.77e-02  8.78e-02  1.73e-01  2.02e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  346.7619   -68.1702   0.0181    38.5132   -23.0966         3.2692915     10.578 TRIG_00332931                 
 
Foreground time interval of the image:
-36.256 270.244 (delta_t = 306.500 [sec])
Background time interval of the image:
-556.799 -465.950 (delta_t =  90.849 [sec])
-239.000 -36.256 (delta_t = 202.744 [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

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  -36.256 sec. to  270.244 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.40691     ( -0.18053   0.181523 )
Norm@50keV  : 7.25083E-04    ( -7.6356e-05   7.61502e-05 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          67.29 using 59 PHA bins.
# Reduced chi-squared =          1.180 for     57 degrees of freedom 
# Null hypothesis probability =   1.654318e-01
 
Photon flux (15-150 keV)    in 306.5 sec: 8.84425E-02 ( -0.0095818  0.0096054 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.14467e-06 ( -2.45645e-07  2.47382e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from  -36.256 sec. to  270.244 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.10067     ( -0.457718   0.791959 )
Epeak [keV] : 149.667      ( -149.686 -149.686 )
Norm@50keV  : 1.03195E-03    ( -0.000407135   0.00148068 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          66.72 using 59 PHA bins.
# Reduced chi-squared =          1.191 for     56 degrees of freedom 
# Null hypothesis probability =   1.547010e-01
 
Photon flux (15-150 keV)    in 306.5 sec: 8.73399E-02 ( -0.0099174  0.0099121 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.09827e-06 ( -2.71762e-07  2.67929e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   20.572 sec. to   21.572 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.739     ( -0.711834   0.631925 )
Norm@50keV  : 3.31807E-03    ( -0.00144476   0.00137176 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          44.01 using 59 PHA bins.
# Reduced chi-squared =         0.7721 for     57 degrees of freedom 
# Null hypothesis probability =   8.961031e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.446872 ( -0.168333  0.168567 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.06422e-08 ( -1.30164e-08  1.37309e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   20.572 sec. to   21.572 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.446697     ( -1.73185   5.12497 )
Epeak [keV] : 53.0231      ( -53.0207 -53.0207 )
Norm@50keV  : 1.73525E-02    ( -0.0173609   16.347 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          43.39 using 59 PHA bins.
# Reduced chi-squared =         0.7749 for     56 degrees of freedom 
# Null hypothesis probability =   8.906983e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.430009 ( -0.171355  0.172516 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.76427e-08 ( -1.23272e-08  1.50762e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 275.104 sec.
Hardness ratio (energy fluence ratio) = 1.50851639316

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

S(15-50 keV)  = 7.659945e-07
S(50-150 keV) = 1.3786756e-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 = 7.320249024235598E-01, IMY = 3.121838585141472E-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:
-556.799400 -465.950000
-239.000000 -36.256000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5107 -40.5694    5.3  46.1 -136.8   1.0889   2.2    1.2	Vela X-1                      
 38.9445 -20.9913    2.6  39.3   75.7   3.0135   4.4 ------	UNKNOWN                       

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

Time interval of the image:
-36.256000 270.244000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.7118 -40.7121    4.6  46.1 -136.5   1.4248   2.5   12.6	Vela X-1                      
338.6058 -48.0346    2.4  52.7   -2.1   3.0775   4.9 ------	UNKNOWN                       
346.7620 -68.1702    1.1  38.5  -23.1   3.2706  10.6 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
836.500600 983.093400
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.4472 -40.6243    1.9  31.2   31.0   0.9509   6.2    5.6	Vela X-1                      
170.5211 -60.5758    5.7  41.8  -16.2   0.3662   2.0    6.7	Cen X-3                       
186.3979 -62.9492    0.0  46.9  -24.8   0.0160   0.1   12.9	GX 301-2                      
138.7719  17.6044    2.4  43.3  136.8   1.7823   4.8 ------	UNKNOWN                       
127.4043 -31.4850    2.2  33.4   51.6   1.0410   5.2 ------	UNKNOWN                       
162.4623   6.8552    2.5  26.0  171.1   0.6003   4.7 ------	UNKNOWN                       
173.4278  36.9657    2.4  57.2 -179.1   3.2238   4.9 ------	UNKNOWN