GRB060904B: 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: Wed Jan 22 13:52:32 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger228006
======================================================================

  Trigger: 00228006      Segment: 000

  BAT Trigger Time: 179029865.28   [s; MET]
      Trigger Stop: 179029865.792   [s; MET]
               UTC: 2006-09-04T02:31:03.857720    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 58.2130876183086   Dec: -0.720064748212814  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    8.68
     Image Trigger?:     NO
     Rate S/N Ratio:     15.52417469626  [ if not an image trigger ]
     Image S/N Ratio:    8.68

  Analysis Position:   [ source = BAT ]
    RA: 58.2130876183086   Dec: -0.720064748212814  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 58.2189835570116   Dec: -0.720092086947652  [deg; J2000]  
        { 03h 52m 52.6s , -00d 43' 12.3" }
         +/- 0.929194727625773 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.367155050868339 [arcmin] (formal 1-sigma fit error)
    SNR: 33.7815976034585
 
  Angular difference between the analysis and refined position is 0.353732 arcmin
 
  Partial Coding Fraction: 0.5078125    [ including projection effects ]

  Duration
     T90: 189.980000019073 +/- 21.1618241080332
        Measured from: 0.391999989748001
                   to: 190.372000008821     [s; relative to TRIGTIME]
     T50: 150.780000001192 +/- 5.20011383503016
        Measured from: 2.56000000238419
                   to: 153.340000003576     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 1.15599998831749     
                   to: 2.15599998831749     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.944000005722046     
                   to: 213.224000006914     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.861110   1.162898   0.697107   0.204765
           0.073156   0.075851   0.066544   0.058684 [error]
 Peak      0.071537   0.099752   0.106942   0.028725
           0.007653   0.008704   0.008251   0.006398 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  214.168   -0.944  213.224
T90   189.980    0.392  190.372
T50   150.780    2.560  153.340
Peak    1.000    1.156    2.156
 
 
====== 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      -1.657    -0.140      0.137       -           -               -         8.60e-04     -7.15e-05          7.08e-05      60.640   57
CPL     -1.234    -0.485      0.635       84.094     -26.655       -84.094      1.45e-03     -6.30e-04          1.68e-03      58.950   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      -1.211     -0.145     0.146       -           -               -         2.06e-02     -1.72e-03          1.72e-03      81.870   57
CPL     -1.061     -0.279     0.608      342.243    -342.243      -342.243      2.43e-02     -5.19e-03          2.17e-02      81.660   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   2.73e-07  4.55e-07  5.78e-07  1.46e-06  1.71e-06  2.77e-06   erg/cm2
      90%_error_low -3.30e-08 -3.51e-08 -6.47e-08 -3.16e-07 -1.51e-07 -3.78e-07   erg/cm2
      90%_error_hi   3.40e-08  3.50e-08  6.48e-08  3.71e-07  1.53e-07  4.22e-07   erg/cm2
Peak flux       PL   6.44e-01  7.70e-01  6.66e-01  9.82e-01  2.43e+00  3.06e+00   ph/cm2/s
      90%_error_low -9.94e-02 -7.45e-02 -6.59e-02 -1.91e-01 -2.07e-01 -2.71e-01   ph/cm2/s
      90%_error_hi   1.04e-01  7.36e-02  6.52e-02  2.18e-01  2.07e-01  2.76e-01   ph/cm2/s
 
Fluence        CPL   2.58e-07  4.77e-07  5.82e-07  7.41e-07  1.64e-06  2.06e-06   erg/cm2
      90%_error_low -3.88e-08 -4.48e-08 -6.90e-08 -4.13e-07 -1.76e-07 -4.53e-07   erg/cm2
      90%_error_hi   3.92e-08  4.63e-08  6.90e-08  8.33e-07  1.78e-07  8.66e-07   erg/cm2
Peak flux      CPL   6.24e-01  7.80e-01  6.77e-01  8.31e-01  2.41e+00  2.91e+00   ph/cm2/s
      90%_error_low -1.24e-01 -7.97e-02 -7.47e-02 -3.70e-01 -2.13e-01 -4.38e-01   ph/cm2/s
      90%_error_hi   1.17e-01  8.32e-02  7.94e-02  2.05e-01  2.10e-01  4.00e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
   58.2190    -0.7201   0.0057    26.2247    67.7340         1.6576966     33.782 TRIG_00228006                 
 
Foreground time interval of the image:
 -0.944  10.421 (delta_t =  11.365 [sec])
Background time interval of the image:
-239.280  -0.944 (delta_t = 238.336 [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   -0.944 sec. to  213.224 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.65742     ( -0.139608   0.137141 )
Norm@50keV  : 8.60359E-04    ( -7.15405e-05   7.08375e-05 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          60.64 using 59 PHA bins.
# Reduced chi-squared =          1.064 for     57 degrees of freedom 
# Null hypothesis probability =   3.460905e-01
 
Photon flux (15-150 keV)    in 214.2 sec: 0.112622 ( -0.008666  0.008673 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.71297e-06 ( -1.51154e-07  1.53066e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.944 sec. to  213.224 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.23373     ( -0.485452   0.635418 )
Epeak [keV] : 84.0941      ( -26.656 -84.0948 )
Norm@50keV  : 1.44818E-03    ( -0.000630344   0.00168078 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          58.95 using 59 PHA bins.
# Reduced chi-squared =          1.053 for     56 degrees of freedom 
# Null hypothesis probability =   3.681247e-01
 
Photon flux (15-150 keV)    in 214.2 sec: 0.110320 ( -0.009204  0.00916 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.64278e-06 ( -1.76054e-07  1.77504e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    1.156 sec. to    2.156 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.21086     ( -0.144936   0.145699 )
Norm@50keV  : 2.06417E-02    ( -0.00172183   0.00172128 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          81.87 using 59 PHA bins.
# Reduced chi-squared =          1.436 for     57 degrees of freedom 
# Null hypothesis probability =   1.710659e-02
 
Photon flux (15-150 keV)    in 1 sec: 2.42669 ( -0.20654  0.20681 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.08805e-07 ( -1.95619e-08  1.97023e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    1.156 sec. to    2.156 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.06144     ( -0.278639   0.60751 )
Epeak [keV] : 342.243      ( -342.242 -342.242 )
Norm@50keV  : 2.43006E-02    ( -0.00519491   0.0217325 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          81.66 using 59 PHA bins.
# Reduced chi-squared =          1.458 for     56 degrees of freedom 
# Null hypothesis probability =   1.424005e-02
 
Photon flux (15-150 keV)    in 1 sec: 2.41344 ( -0.2128  0.21017 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.07157e-07 ( -2.07166e-08  2.05519e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 189.98 sec.
Hardness ratio (energy fluence ratio) = 1.26808968826

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

S(15-50 keV)  = 7.282707e-07
S(50-150 keV) = 9.847138e-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 = 1.866490220671386E-01, IMY = -4.558668020498187E-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:
-239.280000 -0.944000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6343  22.0144    0.2   8.5 -145.7  10.7271  61.9    0.1	Crab                          
 41.9862   1.2142    2.7  39.7   85.0   2.9622   4.2 ------	UNKNOWN                       
 54.5608  -1.6978    2.3  29.8   70.4   1.4175   5.0 ------	UNKNOWN                       
 86.1498 -34.2258    2.7  48.8    3.9   1.7378   4.3 ------	UNKNOWN                       
 84.2354  64.8199    2.8  50.7 -166.9   1.7204   4.1 ------	UNKNOWN                       
108.7337  -4.3360    2.2  34.0  -48.3   1.3231   5.2 ------	UNKNOWN                       

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

Time interval of the image:
-0.944000 10.420590
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6014  22.0005    5.2   8.5 -145.9  -0.0732  -2.2    2.0	Crab                          
 58.2190  -0.7201    0.3  26.2   67.7   1.6579  33.8 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
58.020590 316.020590
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6297  22.0119    0.3  33.6 -126.7  10.8382  41.7    0.2	Crab                          
 42.4765 -13.1534    2.5  19.9   58.1   0.8717   4.6 ------	UNKNOWN                       
 58.2256  -0.7029    1.7   0.0 -155.9   1.1940   6.6 ------	UNKNOWN                       
 68.6379 -43.0310    2.7  43.3   -3.8   1.2286   4.3 ------	UNKNOWN                       
 91.7612  44.1909    2.5  53.9 -143.3   4.6871   4.7 ------	UNKNOWN