GRB091024: 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: Sun Jan 19 13:26:35 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger373674
======================================================================

  Trigger: 00373674      Segment: 000

  BAT Trigger Time: 278067366.464   [s; MET]
      Trigger Stop: 278067367.488   [s; MET]
               UTC: 2009-10-24T08:56:01.265340    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 339.206654153892   Dec: 56.8745686910293  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    9.06
     Image Trigger?:     NO
     Rate S/N Ratio:     19.3907194296653  [ if not an image trigger ]
     Image S/N Ratio:    9.06

  Analysis Position:   [ source = BAT ]
    RA: 339.206654153892   Dec: 56.8745686910293  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 339.238898339272   Dec: 56.8853563019734  [deg; J2000]  
        { 22h 36m 57.3s , +56d 53' 07.3" }
         +/- 0.964013417042147 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.302222774092929 [arcmin] (formal 1-sigma fit error)
    SNR: 32.0521258577268
 
  Angular difference between the analysis and refined position is 1.239503 arcmin
 
  Partial Coding Fraction: 0.390625    [ including projection effects ]

  Duration
     T90: 112.27999997139 +/- 13.7684445322825
        Measured from: -5.69999998807907
                   to: 106.579999983311     [s; relative to TRIGTIME]
     T50: 48.5239999294281 +/- 4.76534155566373
        Measured from: 3.15200001001358
                   to: 51.6759999394417     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.75600004196167     
                   to: 1.75600004196167     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -15.2039999961853     
                   to: 134.98400002718     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     1.644294   2.808311   2.731903   1.120494
           0.112252   0.118203   0.107217   0.095590 [error]
 Peak      0.054027   0.067451   0.099847   0.052562
           0.009811   0.010683   0.010445   0.009120 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  150.188  -15.204  134.984
T90   112.280   -5.700  106.580
T50    48.524    3.152   51.676
Peak    1.000    0.756    1.756
 
 
====== 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      -1.206    -0.079      0.080       -           -               -         3.93e-03     -1.71e-04          1.71e-04      45.580   57
CPL     -1.156    -0.130      0.135      999.039    -999.039      -999.039      4.13e-03     -3.51e-04          3.94e-04      46.440   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      -1.113     -0.229     0.234       -           -               -         1.77e-02     -2.28e-03          2.27e-03      61.520   57
CPL     -0.973     -0.351     0.963      438.378    -438.378      -438.378      2.02e-02     -2.02e-02          -1.57e-02      61.480   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   5.73e-07  1.26e-06  2.19e-06  8.80e-06  5.98e-06  1.28e-05   erg/cm2
      90%_error_low -5.30e-08 -6.96e-08 -1.02e-07 -9.39e-07 -2.62e-07 -9.81e-07   erg/cm2
      90%_error_hi   5.49e-08  6.91e-08  1.02e-07  1.02e-06  2.63e-07  1.05e-06   erg/cm2
Peak flux       PL   5.04e-01  6.39e-01  5.91e-01  9.57e-01  2.06e+00  2.69e+00   ph/cm2/s
      90%_error_low -1.30e-01 -1.05e-01 -8.22e-02 -2.64e-01 -2.76e-01 -3.54e-01   ph/cm2/s
      90%_error_hi   1.44e-01  1.03e-01  8.10e-02  3.21e-01  2.78e-01  3.61e-01   ph/cm2/s
 
Fluence        CPL   5.72e-07  1.26e-06  2.17e-06  9.30e-06  6.00e-06  1.23e-05   erg/cm2
      90%_error_low    N/A    -6.60e-08    N/A    -2.08e-06 -2.81e-07 -1.29e-06   erg/cm2
      90%_error_hi     N/A     7.27e-08    N/A     -1.43e-07  2.44e-07  2.12e-06   erg/cm2
Peak flux      CPL   4.87e-01  6.41e-01  6.00e-01  8.65e-01  2.05e+00  2.59e+00   ph/cm2/s
      90%_error_low -1.79e-01 -5.39e-02 -8.90e-02 -4.47e-01 -2.91e-01 -5.80e-01   ph/cm2/s
      90%_error_hi   1.14e-01  1.07e-01  1.07e-01  2.78e-01  2.85e-01  4.29e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  339.2389    56.8854   0.0060    44.4231   179.6627         9.2327542     32.052 TRIG_00373674                 
 
Foreground time interval of the image:
-15.204 134.984 (delta_t = 150.188 [sec])
Background time interval of the image:
-237.363 -15.204 (delta_t = 222.159 [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  -15.204 sec. to  134.984 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.20592     ( -0.0790486   0.0800151 )
Norm@50keV  : 3.93259E-03    ( -0.00017143   0.000170644 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          45.58 using 59 PHA bins.
# Reduced chi-squared =         0.7997 for     57 degrees of freedom 
# Null hypothesis probability =   8.614815e-01
 
Photon flux (15-150 keV)    in 150.2 sec: 0.461996 ( -0.021877  0.021956 ) ph/cm2/s
Energy fluence (15-150 keV)             : 5.98329e-06 ( -2.6245e-07  2.62823e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from  -15.204 sec. to  134.984 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.20131     ( -0.129647   0.135364 )
Epeak [keV] : 9999.13      ( -9999.14 -9999.14 )
Norm@50keV  : 3.95113E-03    ( -0.000169041   0.00057633 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          45.66 using 59 PHA bins.
# Reduced chi-squared =         0.8153 for     56 degrees of freedom 
# Null hypothesis probability =   8.367020e-01
 
Photon flux (15-150 keV)    in 150.2 sec: 0.461874 ( -0.021874  0.02196 ) ph/cm2/s
Energy fluence (15-150 keV)             : 6.00026e-06 ( -2.80872e-07  2.44125e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    0.756 sec. to    1.756 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.11344     ( -0.228855   0.233506 )
Norm@50keV  : 1.77232E-02    ( -0.00227774   0.00226682 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          61.52 using 59 PHA bins.
# Reduced chi-squared =          1.079 for     57 degrees of freedom 
# Null hypothesis probability =   3.175392e-01
 
Photon flux (15-150 keV)    in 1 sec: 2.05853 ( -0.27572  0.27756 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.84531e-07 ( -2.49468e-08  2.50394e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    0.756 sec. to    1.756 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.78182     ( -0.337931   0.976825 )
Epeak [keV] : 231.437      ( -541.506 -541.506 )
Norm@50keV  : 1.39790E-03    ( -0.00140045   0.00314368 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          58.65 using 59 PHA bins.
# Reduced chi-squared =          1.047 for     56 degrees of freedom 
# Null hypothesis probability =   3.785306e-01
 
Photon flux (15-150 keV)    in 1 sec: 2.04646 ( -0.29113  0.28517 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.84043e-07 ( -2.53528e-08  2.52863e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 112.28 sec.
Hardness ratio (energy fluence ratio) = 1.73400419773

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

S(15-50 keV)  = 1.8341396e-06
S(50-150 keV) = 4.149176e-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 = -9.800457962126508E-01, IMY = -5.769424024744253E-03

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:
-237.363410 -15.204000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6306  22.0083    0.4  37.6   27.6   8.5473  29.1    0.4	Crab                          
 16.3966  37.5830    3.2  39.2  132.8   1.6668   3.6 ------	UNKNOWN                       
350.3983  42.1682    2.8  49.4  158.3   2.4888   4.2 ------	UNKNOWN                       
311.5523  61.1619    2.9  51.2 -162.6   1.6922   3.9 ------	UNKNOWN                       
129.3917  66.6953    3.0  28.3  -82.1   1.0198   3.8 ------	UNKNOWN                       
247.8017  74.0727    2.2  47.9 -128.8   4.8481   5.1 ------	UNKNOWN                       

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

Time interval of the image:
-15.204000 134.984000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.5139  22.1123   11.8  37.5   27.7   0.2604   1.0    8.9	Crab                          
339.2389  56.8853    0.4  44.4  179.7   9.2333  32.1 ------	UNKNOWN                       
334.0666  70.3952    2.2  38.3 -161.7   1.1187   5.2 ------	UNKNOWN                       
116.1470  35.7524    2.5  38.3  -24.7   1.0329   4.6 ------	UNKNOWN                       
269.1386  78.7543    2.3  42.7 -134.9   1.5979   5.0 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
502.836600 962.676000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.4795  35.3439    6.9  56.7 -152.7   2.8194   1.7    1.1	Her X-1                       
121.3323  34.9005    2.7  41.8   43.1   2.8555   4.2 ------	UNKNOWN                       
185.4123  34.3527    3.3  18.1  -72.6   0.9885   3.5 ------	UNKNOWN                       
265.9809  43.8055    2.8  57.6 -167.2   5.3619   4.1 ------	UNKNOWN                       
178.7650   2.7149    3.0  48.3  -50.0   5.9869   3.8 ------	UNKNOWN