GRB121108A: 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 12 23:31:50 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger537921
======================================================================

  Trigger: 00537921      Segment: 000

  BAT Trigger Time: 374089668.928   [s; MET]
      Trigger Stop: 374089669.952   [s; MET]
               UTC: 2012-11-08T17:47:39.076820    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 83.1858158216827   Dec: 54.4907233392431  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.89
     Image Trigger?:     NO
     Rate S/N Ratio:     12.9228479833201  [ if not an image trigger ]
     Image S/N Ratio:    7.89

  Analysis Position:   [ source = BAT ]
    RA: 83.1858158216827   Dec: 54.4907233392431  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 83.2321731033032   Dec: 54.5293066041938  [deg; J2000]  
        { 05h 32m 55.7s , +54d 31' 45.5" }
         +/- 2.37389297059574 [arcmin] (estimated 90% radius based on SNR)
         +/- 1.21320647312007 [arcmin] (formal 1-sigma fit error)
    SNR: 8.84596732348644
 
  Angular difference between the analysis and refined position is 2.822545 arcmin
 
  Partial Coding Fraction: 0.90625    [ including projection effects ]

  Duration
     T90: 89.5479999780655 +/- 47.5364645041382
        Measured from: 0.944000005722046
                   to: 90.4919999837875     [s; relative to TRIGTIME]
     T50: 26.4959999322891 +/- 9.24377933393568
        Measured from: 16.7040000557899
                   to: 43.1999999880791     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 43.188000023365     
                   to: 44.188000023365     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.223999977111816     
                   to: 137.976000010967     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.946279   0.818797   0.273159  -0.052527
           0.067824   0.070062   0.062530   0.059398 [error]
 Peak      0.063645   0.088043   0.041196  -0.001944
           0.006691   0.007078   0.006078   0.005101 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  138.200   -0.224  137.976
T90    89.548    0.944   90.492
T50    26.496   16.704   43.200
Peak    1.000   43.188   44.188
 
 
====== 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: 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      -2.294    -0.204      0.191       -           -               -         7.23e-04     -1.08e-04          1.08e-04      72.400   57
CPL     -1.012    -0.954      1.277       26.548     -23.373         6.771      4.87e-03     -4.87e-03          2.99e-02      66.600   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      -1.811     -0.171     0.165       -           -               -         1.14e-02     -1.37e-03          1.35e-03      68.580   57
CPL     -0.360     -0.815     1.013       45.970      -7.050        12.693      8.14e-02     -8.14e-02          2.49e-01      57.990   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   2.70e-07  3.08e-07  2.51e-07  3.42e-07  9.54e-07  1.17e-06   erg/cm2
      90%_error_low -3.25e-08 -3.28e-08 -4.96e-08 -1.13e-07 -1.17e-07 -1.87e-07   erg/cm2
      90%_error_hi   3.28e-08  3.24e-08  5.26e-08  1.48e-07  1.21e-07  2.13e-07   erg/cm2
Peak flux       PL   6.32e-01  5.30e-01  3.02e-01  2.55e-01  1.58e+00  1.72e+00   ph/cm2/s
      90%_error_low -8.79e-02 -5.35e-02 -4.62e-02 -6.67e-02 -1.59e-01 -1.78e-01   ph/cm2/s
      90%_error_hi   9.00e-02  5.35e-02  4.68e-02  7.97e-02  1.59e-01  1.79e-01   ph/cm2/s
 
Fluence        CPL   2.61e-07  3.48e-07  1.90e-07  3.47e-08  8.28e-07  8.33e-07   erg/cm2
      90%_error_low -3.53e-08 -4.38e-08 -7.47e-08 -2.97e-08 -1.17e-07 -1.22e-07   erg/cm2
      90%_error_hi   3.51e-08  4.49e-08  7.45e-08  1.34e-07  1.38e-07  1.90e-07   erg/cm2
Peak flux      CPL   5.64e-01  6.29e-01  2.88e-01  4.64e-02  1.52e+00  1.53e+00   ph/cm2/s
      90%_error_low -9.94e-02 -7.62e-02 -6.30e-02 -3.12e-02 -1.60e-01 -1.64e-01   ph/cm2/s
      90%_error_hi   1.00e-01  7.90e-02  5.85e-02  6.87e-02  1.61e-01  1.68e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
   83.2322    54.5293   0.0218    11.7291    72.6823         0.3395062      8.846 TRIG_00537921                 
 
Foreground time interval of the image:
 -0.224  10.973 (delta_t =  11.197 [sec])
Background time interval of the image:
-239.928  -0.224 (delta_t = 239.704 [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   -0.224 sec. to  137.976 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.29377     ( -0.203521   0.191197 )
Norm@50keV  : 7.22931E-04    ( -0.000108268   0.000107655 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          72.40 using 59 PHA bins.
# Reduced chi-squared =          1.270 for     57 degrees of freedom 
# Null hypothesis probability =   8.217669e-02
 
Photon flux (15-150 keV)    in 138.2 sec: 0.125916 ( -0.012142  0.012144 ) ph/cm2/s
Energy fluence (15-150 keV)             : 9.53867e-07 ( -1.16573e-07  1.20562e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.224 sec. to  137.976 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.01242     ( -0.954369   1.27689 )
Epeak [keV] : 26.5479      ( -23.3736 6.77112 )
Norm@50keV  : 4.87066E-03    ( -0.00487092   0.0298929 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          66.60 using 59 PHA bins.
# Reduced chi-squared =          1.189 for     56 degrees of freedom 
# Null hypothesis probability =   1.570557e-01
 
Photon flux (15-150 keV)    in 138.2 sec: 0.121320 ( -0.012271  0.01238 ) ph/cm2/s
Energy fluence (15-150 keV)             : 8.27767e-07 ( -1.16622e-07  1.38258e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   43.188 sec. to   44.188 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.81051     ( -0.171451   0.165074 )
Norm@50keV  : 1.13885E-02    ( -0.00137086   0.00135201 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          68.58 using 59 PHA bins.
# Reduced chi-squared =          1.203 for     57 degrees of freedom 
# Null hypothesis probability =   1.400065e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.57583 ( -0.1593  0.15931 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.04821e-07 ( -1.26933e-08  1.29288e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   43.188 sec. to   44.188 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.360391     ( -0.815284   1.01284 )
Epeak [keV] : 45.9702      ( -7.05 12.693 )
Norm@50keV  : 8.13551E-02    ( -0.081356   0.248595 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          57.99 using 59 PHA bins.
# Reduced chi-squared =          1.036 for     56 degrees of freedom 
# Null hypothesis probability =   4.017270e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.52032 ( -0.16011  0.16078 ) ph/cm2/s
Energy fluence (15-150 keV)             : 9.14745e-08 ( -1.28424e-08  1.39958e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = N/A sec.
Hardness ratio (energy fluence ratio) = N/A

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

S(15-50 keV)  = N/A
S(50-150 keV) = N/A

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 = 6.180212998763001E-02, IMY = -1.982083967525541E-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:
-239.928000 -0.224000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6312  22.0179    0.8  42.7   46.7  10.2151  14.1    0.2	Crab                          
106.9539  30.6405    3.0  33.6   12.8   1.0657   3.8 ------	UNKNOWN                       
298.2877  57.6475    3.4  57.6 -165.6   3.6545   3.4 ------	UNKNOWN                       

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

Time interval of the image:
-0.224000 10.972600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6564  22.0237   39.8  42.7   46.6  -0.0385  -0.3    1.4	Crab                          
 83.2322  54.5293    1.3  11.7   72.7   0.3395   8.8 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
43.372590 962.126300
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6339  22.0149    0.3  32.5   35.5  36.6364  37.2    0.0	Crab                          
 45.5589  57.0369    2.6  21.1  148.6   3.2522   4.4 ------	UNKNOWN                       
118.0926   6.9338    3.4  55.2   -7.5   7.8721   3.4 ------	UNKNOWN                       
294.8207  64.2695    5.5  58.8 -159.2  12.8801   2.1 ------	UNKNOWN                       
132.5045  10.1219    4.1  58.9  -24.4  14.8978   2.8 ------	UNKNOWN                       
133.9760  14.1649    4.6  56.3  -28.3   9.1461   2.5 ------	UNKNOWN                       
133.5647  10.9562    3.0  58.8  -25.9  19.7316   3.9 ------	UNKNOWN