GRB080328: 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: Mon Jan 20 03:13:19 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger307931
======================================================================

  Trigger: 00307931      Segment: 000

  BAT Trigger Time: 228384187.264   [s; MET]
      Trigger Stop: 228384188.288   [s; MET]
               UTC: 2008-03-28T08:03:04.588480    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 80.4787347010336   Dec: 47.5240403992213  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    15.28
     Image Trigger?:     NO
     Rate S/N Ratio:     44.2492937796752  [ if not an image trigger ]
     Image S/N Ratio:    15.28

  Analysis Position:   [ source = BAT ]
    RA: 80.4787347010336   Dec: 47.5240403992213  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 80.4924038257713   Dec: 47.5232496448004  [deg; J2000]  
        { 05h 21m 58.2s , +47d 31' 23.7" }
         +/- 0.662184701503983 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.282887559723389 [arcmin] (formal 1-sigma fit error)
    SNR: 54.8103356228709
 
  Angular difference between the analysis and refined position is 0.555863 arcmin
 
  Partial Coding Fraction: 0.3710938    [ including projection effects ]

  Duration
     T90: 91.108000010252 +/- 1.68166109404395
        Measured from: 0.0839999914169312
                   to: 91.1920000016689     [s; relative to TRIGTIME]
     T50: 66.1719999909401 +/- 1.20136588015819
        Measured from: 10.080000013113
                   to: 76.2520000040531     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 9.28000000119209     
                   to: 10.2800000011921     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -2.24399998784065     
                   to: 120.620000004768     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     3.677895   5.021987   4.404670   1.451264
           0.078031   0.083883   0.077334   0.068424 [error]
 Peak      0.096238   0.200809   0.283020   0.131714
           0.010758   0.012742   0.014157   0.012130 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  122.864   -2.244  120.620
T90    91.108    0.084   91.192
T50    66.172   10.080   76.252
Peak    1.000    9.280   10.280
 
 
====== 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      -1.408    -0.042      0.042       -           -               -         8.02e-03     -1.70e-04          1.70e-04      55.520   57
CPL     -1.371    -0.102      0.074      979.331    -979.331      -979.331      8.33e-03     -4.52e-04          3.61e-04      56.670   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      -0.837     -0.105     0.107       -           -               -         4.75e-02     -2.99e-03          2.96e-03      86.360   57
CPL     -0.670     -0.213     0.443      498.737    -498.737      -498.737      5.56e-02     -1.00e-02          2.75e-02      85.880   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   1.15e-06  2.25e-06  3.38e-06  1.11e-05  9.51e-06  1.78e-05   erg/cm2
      90%_error_low -5.37e-08 -6.01e-08 -8.24e-08 -6.36e-07 -2.06e-07 -6.65e-07   erg/cm2
      90%_error_hi   5.48e-08  5.99e-08  8.20e-08  6.63e-07  2.06e-07  6.87e-07   erg/cm2
Peak flux       PL   1.04e+00  1.56e+00  1.74e+00  3.70e+00  5.46e+00  8.04e+00   ph/cm2/s
      90%_error_low -1.37e-01 -1.29e-01 -1.06e-01 -4.71e-01 -3.37e-01 -5.28e-01   ph/cm2/s
      90%_error_hi   1.44e-01  1.28e-01  1.05e-01  5.14e-01  3.38e-01  5.41e-01   ph/cm2/s
 
Fluence        CPL   1.15e-06  2.25e-06  3.39e-06  1.10e-05  9.57e-06  1.79e-05   erg/cm2
      90%_error_low    N/A    -6.01e-08 -8.24e-08    N/A    -2.61e-07 -1.50e-06   erg/cm2
      90%_error_hi     N/A     6.00e-08  8.22e-08    N/A     1.51e-07  2.19e-07   erg/cm2
Peak flux      CPL   9.87e-01  1.56e+00  1.78e+00  3.17e+00  5.43e+00  7.51e+00   ph/cm2/s
      90%_error_low -1.82e-01 -1.32e-01 -1.18e-01 -9.72e-01 -3.45e-01 -1.04e+00   ph/cm2/s
      90%_error_hi   9.38e-02  1.32e-01  1.45e-01  6.63e-01  3.46e-01  7.93e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
   80.4924    47.5232   0.0035    45.0336     2.0473         6.7397717     54.810 TRIG_00307931                 
 
Foreground time interval of the image:
 -2.244  19.637 (delta_t =  21.881 [sec])
Background time interval of the image:
-239.264  -2.244 (delta_t = 237.020 [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   -2.244 sec. to  120.620 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.40794     ( -0.0415358   0.0416571 )
Norm@50keV  : 8.02198E-03    ( -0.000170339   0.000170198 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          55.52 using 59 PHA bins.
# Reduced chi-squared =         0.9740 for     57 degrees of freedom 
# Null hypothesis probability =   5.307797e-01
 
Photon flux (15-150 keV)    in 122.9 sec: 0.978721 ( -0.023973  0.024069 ) ph/cm2/s
Energy fluence (15-150 keV)             : 9.51221e-06 ( -2.05596e-07  2.05897e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -2.244 sec. to  120.620 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.40449     ( -0.101566   0.0741164 )
Epeak [keV] : 9998.75      ( -9998.77 -9998.77 )
Norm@50keV  : 8.04997E-03    ( -0.000169102   0.0006437 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          55.61 using 59 PHA bins.
# Reduced chi-squared =         0.9931 for     56 degrees of freedom 
# Null hypothesis probability =   4.894536e-01
 
Photon flux (15-150 keV)    in 122.9 sec: 0.978426 ( -0.023963  0.024084 ) ph/cm2/s
Energy fluence (15-150 keV)             : 9.56537e-06 ( -2.60893e-07  1.50506e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    9.280 sec. to   10.280 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.837181     ( -0.104507   0.106768 )
Norm@50keV  : 4.75190E-02    ( -0.00298625   0.00296418 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          86.36 using 59 PHA bins.
# Reduced chi-squared =          1.515 for     57 degrees of freedom 
# Null hypothesis probability =   7.278158e-03
 
Photon flux (15-150 keV)    in 1 sec: 5.45588 ( -0.33747  0.33807 ) ph/cm2/s
Energy fluence (15-150 keV)             : 5.46865e-07 ( -3.40272e-08  3.41e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    9.280 sec. to   10.280 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.669985     ( -0.213161   0.442996 )
Epeak [keV] : 498.737      ( -498.737 -498.737 )
Norm@50keV  : 5.56390E-02    ( -0.00999725   0.0275377 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          85.88 using 59 PHA bins.
# Reduced chi-squared =          1.534 for     56 degrees of freedom 
# Null hypothesis probability =   6.261949e-03
 
Photon flux (15-150 keV)    in 1 sec: 5.42627 ( -0.34452  0.34556 ) ph/cm2/s
Energy fluence (15-150 keV)             : 5.45268e-07 ( -3.45631e-08  3.44676e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 91.108 sec.
Hardness ratio (energy fluence ratio) = 1.50744009706

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

S(15-50 keV)  = 3.399999e-06
S(50-150 keV) = 6.112324e-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 = 1.000534735716935E+00, IMY = -3.576715780596132E-02

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:
-239.264000 -2.244000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6348  22.0155    0.2  24.7   30.7  10.2714  52.3    0.1	Crab                          
102.7582  -2.6695    2.5  37.5   88.1   2.8080   4.7 ------	UNKNOWN                       
 73.1035 -37.8079    2.9  42.6  159.6   1.6185   4.0 ------	UNKNOWN                       
 50.9275  -4.8073    3.2  17.5 -133.2   0.6960   3.6 ------	UNKNOWN                       
 36.9405  14.6149    3.2  30.3  -80.0   1.0632   3.6 ------	UNKNOWN                       

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

Time interval of the image:
-2.244000 19.636600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.4940  22.0760   18.6  24.7   30.4   0.0441   0.6    8.6	Crab                          
 77.3361 -43.7175    2.8  49.1  157.1   0.7460   4.1 ------	UNKNOWN                       
 68.0650 -24.2295    2.7  28.6  163.8   0.2933   4.4 ------	UNKNOWN                       
 80.4910  47.5235    0.2  45.0    2.0   6.7532  54.9 ------	UNKNOWN                       
 47.1013  -4.0183    3.0  20.5 -125.6   0.2376   3.9 ------	UNKNOWN                       
 29.9935  41.7746    2.4  49.3  -47.1   1.2625   4.7 ------	UNKNOWN                       
 26.9084  23.3529    2.5  42.1  -71.3   1.0182   4.6 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
88.036600 962.798700
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6392  22.0147    0.2  25.7 -176.2  37.4976  75.1    0.3	Crab                          
106.2348  84.2408    3.8  37.3   14.8   1.9820   3.1 ------	UNKNOWN                       
 87.1454  16.6541    3.0  31.4  178.2   2.1822   3.9 ------	UNKNOWN                       
 37.7596  69.6090    2.6  30.2  -17.4   2.3205   4.4 ------	UNKNOWN                       
 19.6122  63.7342    0.7  36.2  -30.2  11.5851  17.5 ------	UNKNOWN                       
 50.5151  33.8851    3.1  26.2  -99.8   2.4080   3.8 ------	UNKNOWN