GRB060904A: 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 14:02:42 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger227996
======================================================================

  Trigger: 00227996      Segment: 000

  BAT Trigger Time: 179024602.624   [s; MET]
      Trigger Stop: 179024603.648   [s; MET]
               UTC: 2006-09-04T01:03:21.201840    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 237.743100468034   Dec: 44.9659595410251  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.71
     Image Trigger?:     NO
     Rate S/N Ratio:     12.1243556529821  [ if not an image trigger ]
     Image S/N Ratio:    7.71

  Analysis Position:   [ source = BAT ]
    RA: 237.743100468034   Dec: 44.9659595410251  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 237.738873815242   Dec: 44.9853710635816  [deg; J2000]  
        { 15h 50m 57.3s , +44d 59' 07.3" }
         +/- 1.51048193891922 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.570196053089405 [arcmin] (formal 1-sigma fit error)
    SNR: 16.8748158356727
 
  Angular difference between the analysis and refined position is 1.178427 arcmin
 
  Partial Coding Fraction: 0.9375    [ including projection effects ]

  Duration
     T90: 80.0600000023842 +/- 2.21841745547793
        Measured from: -0.920000016689301
                   to: 79.1399999856949     [s; relative to TRIGTIME]
     T50: 25.891999989748 +/- 1.91429151152794
        Measured from: 34.5
                   to: 60.391999989748     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 55.339999973774     
                   to: 56.339999973774     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -23.8880000114441     
                   to: 109.759999990463     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     3.729578   4.891257   3.629776   0.876259
           0.057203   0.060701   0.054790   0.048081 [error]
 Peak      0.142439   0.214851   0.220396   0.065028
           0.006627   0.007753   0.007745   0.005730 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  133.648  -23.888  109.760
T90    80.060   -0.920   79.140
T50    25.892   34.500   60.392
Peak    1.000   55.340   56.340
 
 
====== 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      -1.540    -0.038      0.038       -           -               -         6.22e-03     -1.16e-04          1.16e-04      35.610   57
CPL     -1.512    -0.043      0.128      997.506    -997.506      -997.506      6.39e-03     -2.76e-04          8.46e-04      35.680   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      -1.129     -0.070     0.070       -           -               -         4.22e-02     -1.60e-03          1.60e-03      62.810   57
CPL     -1.125     -0.069     0.072     9999.220    -9999.220      -9999.220      4.24e-02     -1.60e-03          1.60e-03      62.850   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   1.10e-06  1.97e-06  2.72e-06  7.75e-06  7.83e-06  1.35e-05   erg/cm2
      90%_error_low -4.45e-08 -4.51e-08 -6.16e-08 -4.14e-07 -1.50e-07 -4.38e-07   erg/cm2
      90%_error_hi   4.53e-08  4.50e-08  6.14e-08  4.31e-07  1.50e-07  4.51e-07   erg/cm2
Peak flux       PL   1.22e+00  1.53e+00  1.40e+00  2.23e+00  4.91e+00  6.38e+00   ph/cm2/s
      90%_error_low -9.38e-02 -7.08e-02 -6.15e-02 -2.10e-01 -1.91e-01 -2.63e-01   ph/cm2/s
      90%_error_hi   9.65e-02  7.04e-02  6.11e-02  2.23e-01  1.92e-01  2.65e-01   ph/cm2/s
 
Fluence        CPL   1.10e-06  1.97e-06  2.72e-06  7.69e-06  7.83e-06  1.33e-05   erg/cm2
      90%_error_low -6.13e-08 -4.38e-08 -6.41e-08 -1.48e-06 -1.71e-07 -1.17e-06   erg/cm2
      90%_error_hi   3.42e-08  4.63e-08  6.65e-08  3.32e-07  1.51e-07  6.68e-07   erg/cm2
Peak flux      CPL   1.22e+00  1.53e+00  1.40e+00  2.22e+00  4.91e+00  6.58e+00   ph/cm2/s
      90%_error_low     N/A   -7.08e-02     N/A       N/A   -1.91e-01 -7.00e-01   ph/cm2/s
      90%_error_hi      N/A    7.04e-02     N/A       N/A    1.92e-01  6.01e-02   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  237.7389    44.9854   0.0114    13.6843   132.5773         1.7044509     16.875 TRIG_00227996                 
 
Foreground time interval of the image:
-23.888  15.677 (delta_t =  39.565 [sec])
Background time interval of the image:
-47.523 -23.888 (delta_t =  23.635 [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  -23.888 sec. to  109.760 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.53997     ( -0.0377549   0.0377607 )
Norm@50keV  : 6.21667E-03    ( -0.000115626   0.000115619 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          35.61 using 59 PHA bins.
# Reduced chi-squared =         0.6248 for     57 degrees of freedom 
# Null hypothesis probability =   9.882021e-01
 
Photon flux (15-150 keV)    in 133.6 sec: 0.784751 ( -0.017158  0.01723 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.83135e-06 ( -1.50021e-07  1.50001e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from  -23.888 sec. to  109.760 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.53736     ( -0.0425385   0.128094 )
Epeak [keV] : 9998.68      ( -9998.68 -9998.68 )
Norm@50keV  : 6.23358E-03    ( -0.000115819   0.00100622 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          35.61 using 59 PHA bins.
# Reduced chi-squared =         0.6359 for     56 degrees of freedom 
# Null hypothesis probability =   9.846974e-01
 
Photon flux (15-150 keV)    in 133.6 sec: 0.784289 ( -0.020101  0.017373 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.82756e-06 ( -1.71477e-07  1.51406e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   55.340 sec. to   56.340 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.12872     ( -0.0698484   0.0701031 )
Norm@50keV  : 4.22197E-02    ( -0.00159859   0.00159833 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          62.81 using 59 PHA bins.
# Reduced chi-squared =          1.102 for     57 degrees of freedom 
# Null hypothesis probability =   2.780928e-01
 
Photon flux (15-150 keV)    in 1 sec: 4.91174 ( -0.19131  0.19161 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.37502e-07 ( -1.86313e-08  1.8703e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   55.340 sec. to   56.340 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.12472     ( -0.0694907   0.0714634 )
Epeak [keV] : 9999.22      ( -9999.32 -9999.32 )
Norm@50keV  : 4.24400E-02    ( -0.00160484   0.00160506 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          62.85 using 59 PHA bins.
# Reduced chi-squared =          1.122 for     56 degrees of freedom 
# Null hypothesis probability =   2.467372e-01
 
Photon flux (15-150 keV)    in 1 sec: 4.91052 ( -0.19137  0.19152 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.39228e-07 ( -2.33365e-08  1.20249e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 80.06 sec.
Hardness ratio (energy fluence ratio) = 1.375624365

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

S(15-50 keV)  = 3.075455e-06
S(50-150 keV) = 4.755835e-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 = -1.647376226583960E-01, IMY = -1.792931515480695E-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:
-47.523410 -23.888000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.4423  35.1963    4.5  29.7  136.4   0.1656   2.6    8.8	Her X-1                       
289.7059  63.1447    2.4  39.6   74.0   0.8448   4.9 ------	UNKNOWN                       
203.7302   3.4355    2.0  47.5 -127.9   1.1033   5.8 ------	UNKNOWN                       

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

Time interval of the image:
-23.888000 15.676580
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.6204  35.4920   10.4  29.6  135.8   0.1469   1.1   12.0	Her X-1                       
346.2245  79.2827    2.1  47.9   43.3   2.4851   5.5 ------	UNKNOWN                       
237.7389  44.9854    0.7  13.7  132.6   1.7043  16.9 ------	UNKNOWN                       
220.4297  -8.1948    2.0  57.4 -150.4   3.2740   5.6 ------	UNKNOWN                       
148.5592  36.6101    2.7  50.9  -44.6   1.8870   4.2 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
54.476600 962.454000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.4162  35.2487    2.9  16.0  127.3   1.7560   4.0    6.0	Her X-1                       
274.8838  24.9520    2.5  36.0  116.8   4.0472   4.6 ------	UNKNOWN                       
322.1437  82.2363    2.3  44.8   16.6   4.1185   5.1 ------	UNKNOWN                       
244.8351  -8.8828    3.4  54.2  176.9   5.2648   3.4 ------	UNKNOWN                       
237.7294  44.9845    0.8   0.0  -82.4   6.3836  14.6 ------	UNKNOWN                       
207.0226  33.2325    5.4  26.4 -100.2   1.1613   2.1 ------	UNKNOWN                       
217.6741  -1.5319    3.4  49.8 -147.7   3.4922   3.4 ------	UNKNOWN