GRB060421: 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 17:22:22 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger206257
======================================================================

  Trigger: 00206257      Segment: 000

  BAT Trigger Time: 167272764.48   [s; MET]
      Trigger Stop: 167272764.736   [s; MET]
               UTC: 2006-04-21T00:39:23.334720    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 343.630155574858   Dec: 62.7269646414008  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    8.34
     Image Trigger?:     NO
     Rate S/N Ratio:     25.5929677841395  [ if not an image trigger ]
     Image S/N Ratio:    8.34

  Analysis Position:   [ source = BAT ]
    RA: 343.630155574858   Dec: 62.7269646414008  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 343.639206714245   Dec: 62.7354522845875  [deg; J2000]  
        { 22h 54m 33.4s , +62d 44' 07.6" }
         +/- 0.766789577044095 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.193999179312389 [arcmin] (formal 1-sigma fit error)
    SNR: 44.4494779288581
 
  Angular difference between the analysis and refined position is 0.566792 arcmin
 
  Partial Coding Fraction: 0.8203125    [ including projection effects ]

  Duration
     T90: 11.9960000216961 +/- 3.2577102430472
        Measured from: -0.747999995946884
                   to: 11.2480000257492     [s; relative to TRIGTIME]
     T50: 6.33599999547005 +/- 0.87591779605344
        Measured from: 1.22800001502037
                   to: 7.56400001049042     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 2.27600002288818     
                   to: 3.27600002288818     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -2.7960000038147     
                   to: 16.8760000169277     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.553315   0.721837   0.592774   0.097850
           0.024818   0.026278   0.023621   0.020197 [error]
 Peak      0.067006   0.141018   0.125645   0.032197
           0.006196   0.007226   0.006905   0.005221 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   19.672   -2.796   16.876
T90    11.996   -0.748   11.248
T50     6.336    1.228    7.564
Peak    1.000    2.276    3.276
 
 
====== 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      -1.521    -0.075      0.074       -           -               -         6.75e-03     -2.80e-04          2.79e-04      62.500   57
CPL     -1.188    -0.284      0.304      126.320     -37.245       348.714      9.80e-03     -2.61e-03          3.85e-03      58.440   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      -1.177     -0.096     0.096       -           -               -         2.49e-02     -1.44e-03          1.44e-03      59.720   57
CPL     -0.732     -0.368     0.402      152.162     -48.535       396.281      4.09e-02     -1.34e-02          2.21e-02      55.370   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   1.73e-07  3.14e-07  4.37e-07  1.27e-06  1.26e-06  2.20e-06   erg/cm2
      90%_error_low -1.28e-08 -1.39e-08 -2.34e-08 -1.44e-07 -5.62e-08 -1.61e-07   erg/cm2
      90%_error_hi   1.31e-08  1.39e-08  2.33e-08  1.56e-07  5.65e-08  1.70e-07   erg/cm2
Peak flux       PL   7.53e-01  9.19e-01  8.13e-01  1.24e+00  2.92e+00  3.72e+00   ph/cm2/s
      90%_error_low -8.07e-02 -6.24e-02 -5.37e-02 -1.61e-01 -1.73e-01 -2.28e-01   ph/cm2/s
      90%_error_hi   8.34e-02  6.19e-02  5.34e-02  1.76e-01  1.73e-01  2.30e-01   ph/cm2/s
 
Fluence        CPL   1.62e-07  3.22e-07  4.47e-07  7.94e-07  1.22e-06  1.73e-06   erg/cm2
      90%_error_low -1.56e-08 -1.59e-08 -2.53e-08 -2.49e-07 -6.24e-08 -2.55e-07   erg/cm2
      90%_error_hi   1.59e-08  1.61e-08  2.56e-08  3.90e-07  6.23e-08  3.89e-07   erg/cm2
Peak flux      CPL   6.88e-01  9.56e-01  8.54e-01  7.73e-01  2.88e+00  3.27e+00   ph/cm2/s
      90%_error_low -9.53e-02 -7.08e-02 -6.38e-02 -2.39e-01 -1.76e-01 -2.96e-01   ph/cm2/s
      90%_error_hi   9.78e-02  7.20e-02  6.47e-02  3.69e-01  1.76e-01  3.87e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  343.6392    62.7355   0.0043    28.9498  -178.8907         1.8699315     44.449 TRIG_00206257                 
 
Foreground time interval of the image:
 -2.796  10.821 (delta_t =  13.617 [sec])
Background time interval of the image:
-239.480  -2.796 (delta_t = 236.684 [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   -2.796 sec. to   16.876 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.52057     ( -0.0746901   0.0744831 )
Norm@50keV  : 6.74979E-03    ( -0.000279819   0.00027948 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          62.50 using 59 PHA bins.
# Reduced chi-squared =          1.097 for     57 degrees of freedom 
# Null hypothesis probability =   2.871516e-01
 
Photon flux (15-150 keV)    in 19.67 sec: 0.847409 ( -0.03638  0.036447 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.25555e-06 ( -5.62338e-08  5.64498e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -2.796 sec. to   16.876 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.18775     ( -0.28412   0.304239 )
Epeak [keV] : 126.320      ( -37.2447 348.714 )
Norm@50keV  : 9.79977E-03    ( -0.00260726   0.00384588 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          58.44 using 59 PHA bins.
# Reduced chi-squared =          1.044 for     56 degrees of freedom 
# Null hypothesis probability =   3.858214e-01
 
Photon flux (15-150 keV)    in 19.67 sec: 0.830699 ( -0.038935  0.038962 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.22452e-06 ( -6.23608e-08  6.22636e-08 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    2.276 sec. to    3.276 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.17729     ( -0.0955567   0.0964328 )
Norm@50keV  : 2.49235E-02    ( -0.00144293   0.0014429 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          59.72 using 59 PHA bins.
# Reduced chi-squared =          1.048 for     57 degrees of freedom 
# Null hypothesis probability =   3.771963e-01
 
Photon flux (15-150 keV)    in 1 sec: 2.91651 ( -0.17334  0.17348 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.54536e-07 ( -1.61943e-08  1.62648e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    2.276 sec. to    3.276 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.732189     ( -0.368388   0.40233 )
Epeak [keV] : 152.162      ( -48.5363 396.28 )
Norm@50keV  : 4.08884E-02    ( -0.0134434   0.0221153 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          55.37 using 59 PHA bins.
# Reduced chi-squared =         0.9888 for     56 degrees of freedom 
# Null hypothesis probability =   4.986375e-01
 
Photon flux (15-150 keV)    in 1 sec: 2.87736 ( -0.17645  0.17648 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.48296e-07 ( -1.73396e-08  1.72501e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 11.996 sec.
Hardness ratio (energy fluence ratio) = 1.39424826956

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

S(15-50 keV)  = 4.864565e-07
S(50-150 keV) = 7.690937e-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 = -5.530599133369802E-01, IMY = 1.070934387382703E-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:
-239.480000 -2.796000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
299.5756  35.2024    0.6  32.3  100.4   6.3917  18.2    0.7	Cyg X-1                       
308.1273  41.1015    7.6  25.4  112.3   0.3360   1.5    9.0	Cyg X-3                       
326.3257  38.1847    5.7  11.1  112.9   0.3295   2.0   11.0	Cyg X-2                       
 84.3472  82.8329    2.7  58.2 -175.1   4.0321   4.2 ------	UNKNOWN                       
358.1694 -21.9708    3.1  58.8  -24.0   4.3284   3.7 ------	UNKNOWN                       

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

Time interval of the image:
-2.796000 10.820600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
299.4020  35.1915   10.1  32.5  100.4   0.0871   1.1    9.3	Cyg X-1                       
308.0935  40.8843    5.5  25.4  111.7   0.1178   2.1    4.2	Cyg X-3                       
326.1842  38.4705    4.6  11.3  114.1  -0.0997  -2.5    9.0	Cyg X-2                       
277.1639  77.3149    2.2  50.9  162.3   0.7269   5.2 ------	UNKNOWN                       
334.1073  12.9689    2.3  21.4   10.0   0.1997   5.0 ------	UNKNOWN                       
343.6392  62.7354    0.3  28.9 -178.9   1.8700  44.5 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
70.820600 743.520600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
299.5902  35.2015    0.4  38.6   28.6  17.5421  28.8    0.0	Cyg X-1                       
308.0434  41.0882    8.3  30.1   24.0  -0.5567  -1.4    8.7	Cyg X-3                       
326.2435  38.2876    6.0  26.6   -5.4   0.7155   1.9    4.0	Cyg X-2                       
309.1625  32.3592    3.0  37.3   15.0   1.8135   3.9 ------	UNKNOWN                       
319.9655  65.1935    2.5  10.6   77.0   1.3647   4.7 ------	UNKNOWN