GRB050326: 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 22:37:20 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger112453
======================================================================

  Trigger: 00112453      Segment: 000

  BAT Trigger Time: 133523635.584   [s; MET]
      Trigger Stop: 133523636.096   [s; MET]
               UTC: 2005-03-26T09:53:56.135600    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 6.85721390690823   Dec: -71.375078177145  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    21
     Image Trigger?:     NO
     Rate S/N Ratio:     116.1034021896  [ if not an image trigger ]
     Image S/N Ratio:    21

  Analysis Position:   [ source = BAT ]
    RA: 6.85721390690823   Dec: -71.375078177145  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 6.88115047028435   Dec: -71.3744347753356  [deg; J2000]  
        { 00h 27m 31.5s , -71d 22' 28.0" }
         +/- 0.545401932441427 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.163369186079349 [arcmin] (formal 1-sigma fit error)
    SNR: 72.3165034317991
 
  Angular difference between the analysis and refined position is 0.460309 arcmin
 
  Partial Coding Fraction: 0.4804688    [ including projection effects ]

  Duration
     T90: 29.440000012517 +/- 1.13471053573939
        Measured from: -5.08400000631809
                   to: 24.3560000061989     [s; relative to TRIGTIME]
     T50: 19.3880000114441 +/- 0.138679478372513
        Measured from: 0.703999996185303
                   to: 20.0920000076294     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.0800000131130219     
                   to: 0.919999986886978     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -9.84000000357628     
                   to: 32.4239999949932     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     2.887378   4.613173   4.233984   1.238749
           0.046974   0.053397   0.051521   0.044201 [error]
 Peak      0.270390   0.518760   0.582673   0.203919
           0.010955   0.013988   0.014992   0.011322 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   42.264   -9.840   32.424
T90    29.440   -5.084   24.356
T50    19.388    0.704   20.092
Peak    1.000   -0.080    0.920
 
 
====== 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      -1.261    -0.032      0.033       -           -               -         2.10e-02     -3.61e-04          3.61e-04      46.850   57
CPL     -1.155    -0.117      0.134      484.079    -234.674      -484.079      2.32e-02     -1.57e-03          3.09e-03      44.970   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      -0.964     -0.053     0.054       -           -               -         1.07e-01     -3.21e-03          3.20e-03      54.880   57
CPL     -0.817     -0.175     0.219      477.405    -477.405      -477.405      1.24e-01     -1.84e-02          2.91e-02      53.460   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   9.05e-07  1.93e-06  3.21e-06  1.22e-05  8.84e-06  1.83e-05   erg/cm2
      90%_error_low -3.44e-08 -4.26e-08 -5.94e-08 -5.40e-07 -1.52e-07 -5.58e-07   erg/cm2
      90%_error_hi   3.50e-08  4.26e-08  5.93e-08  5.57e-07  1.52e-07  5.72e-07   erg/cm2
Peak flux       PL   9.99e-04  1.21e-02  1.61e-01  1.42e+01  5.95e-01  1.44e+01   ph/cm2/s
      90%_error_low     N/A       N/A       N/A       N/A       N/A       N/A     ph/cm2/s
      90%_error_hi      N/A       N/A       N/A       N/A       N/A       N/A     ph/cm2/s
 
Fluence        CPL   8.76e-07  1.93e-06  3.25e-06  1.08e-05  8.80e-06  1.68e-05   erg/cm2
      90%_error_low -4.81e-08 -4.34e-08 -7.21e-08 -1.54e-06 -1.62e-07 -1.54e-06   erg/cm2
      90%_error_hi   2.47e-08  4.35e-08  7.35e-08  1.57e-06  1.62e-07  1.59e-06   erg/cm2
Peak flux      CPL   2.53e+00  3.68e+00  3.82e+00  6.06e+00  1.22e+01  1.61e+01   ph/cm2/s
      90%_error_low -2.21e-01 -1.45e-01 -1.32e-01 -1.14e+00 -3.89e-01 -1.21e+00   ph/cm2/s
      90%_error_hi   2.23e-01  1.45e-01  1.55e-01  1.11e+00  3.89e-01  1.24e+00   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
    6.8812   -71.3744   0.0027    26.5586    78.2767         6.3594497     72.317 TRIG_00112453                 
 
Foreground time interval of the image:
 -9.840   6.317 (delta_t =  16.157 [sec])
Background time interval of the image:
-226.283  -9.840 (delta_t = 216.443 [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   -9.840 sec. to   32.424 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.26088     ( -0.0324373   0.0325241 )
Norm@50keV  : 2.09674E-02    ( -0.000361268   0.000360667 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          46.85 using 59 PHA bins.
# Reduced chi-squared =         0.8220 for     57 degrees of freedom 
# Null hypothesis probability =   8.289529e-01
 
Photon flux (15-150 keV)    in 42.26 sec: 2.48435 ( -0.04785  0.04799 ) ph/cm2/s
Energy fluence (15-150 keV)             : 8.84379e-06 ( -1.51997e-07  1.51794e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -9.840 sec. to   32.424 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.15514     ( -0.116661   0.134467 )
Epeak [keV] : 484.079      ( -234.699 -484.104 )
Norm@50keV  : 2.31928E-02    ( -0.00156526   0.00309014 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          44.97 using 59 PHA bins.
# Reduced chi-squared =         0.8031 for     56 degrees of freedom 
# Null hypothesis probability =   8.543707e-01
 
Photon flux (15-150 keV)    in 42.26 sec: 2.46353 ( -0.05374  0.05403 ) ph/cm2/s
Energy fluence (15-150 keV)             : 8.7979e-06 ( -1.62358e-07  1.61926e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   -0.080 sec. to    0.920 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.963991     ( -0.053433   0.0537814 )
Norm@50keV  : 0.106889    ( -0.00320989   0.00320284 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          54.88 using 59 PHA bins.
# Reduced chi-squared =         0.9629 for     57 degrees of freedom 
# Null hypothesis probability =   5.549133e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.594660 (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.17109e-06 ( -3.78549e-08  3.78925e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.080 sec. to    0.920 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.816588     ( -0.17518   0.219077 )
Epeak [keV] : 477.405      ( -477.405 -477.405 )
Norm@50keV  : 0.123710    ( -0.0183983   0.0290526 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          53.46 using 59 PHA bins.
# Reduced chi-squared =         0.9546 for     56 degrees of freedom 
# Null hypothesis probability =   5.716980e-01
 
Photon flux (15-150 keV)    in 1 sec: 12.2077 ( -0.3891  0.3895 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.16415e-06 ( -3.94155e-08  3.92777e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 29.44 sec.
Hardness ratio (energy fluence ratio) = 1.66916774154

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

S(15-50 keV)  = 2.8297491e-06
S(50-150 keV) = 6.013932e-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 = 1.015638606379468E-01, IMY = -4.894329814326609E-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:
-226.283410 -9.840000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
289.8666 -56.7538    2.8  43.7  131.5   2.4948   4.1 ------	UNKNOWN                       
 38.0936  -6.5313    3.1  50.7  -44.5   2.9911   3.7 ------	UNKNOWN                       
  8.7145  -4.7530    2.2  41.0  -83.5   3.2966   5.2  595.1	UNKNOWN                       

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

Time interval of the image:
-9.840000 6.316600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
  6.8811 -71.3744    0.2  26.6   78.3   6.3593  72.3 ------	UNKNOWN                       
 36.6245 -39.2954    2.4  27.5   -5.8   0.2917   4.8 ------	UNKNOWN                       
333.4144 -12.5383    2.8  39.6 -140.1   0.3691   4.2 ------	UNKNOWN                       
311.3076  -4.0238    3.0  59.0 -157.8   1.2347   3.9 ------	UNKNOWN                       
326.1984  -1.6151    2.9  52.6 -141.2   0.9486   3.9 ------	UNKNOWN                       
337.3444  -1.7338    2.6  47.7 -128.2   0.9724   4.4 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
85.316600 302.503600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5373 -40.5819    4.5  38.1   74.8   1.6575   2.5    1.7	Vela X-1                      
170.2632 -60.6630    4.3  42.2  120.4  -1.7801  -2.7    2.9	Cen X-3                       
209.4477 -71.8234    2.8  45.6  147.2   1.9311   4.2 ------	UNKNOWN                       
 68.3973 -16.6591    2.3  42.1  -31.2   1.2081   5.1 ------	UNKNOWN                       
 63.5375  -8.5284    3.2  51.0  -35.4   1.8954   3.6 ------	UNKNOWN                       
  8.1109 -45.4072    3.1  44.7 -119.9   2.2373   3.7 ------	UNKNOWN