GRB120911A: 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: Mon Jan 13 01:01:29 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger533268
======================================================================

  Trigger: 00533268      Segment: 000

  BAT Trigger Time: 369040123.392   [s; MET]
      Trigger Stop: 369040124.416   [s; MET]
               UTC: 2012-09-11T07:08:33.754960    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 357.960763192049   Dec: 63.0987077305092  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    11.79
     Image Trigger?:     NO
     Rate S/N Ratio:     20.7846096908265  [ if not an image trigger ]
     Image S/N Ratio:    11.79

  Analysis Position:   [ source = BAT ]
    RA: 357.960763192049   Dec: 63.0987077305092  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 357.966505198214   Dec: 63.0901179230837  [deg; J2000]  
        { 23h 51m 52.0s , +63d 05' 24.4" }
         +/- 1.5861721238515 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.894022123582005 [arcmin] (formal 1-sigma fit error)
    SNR: 15.7363369772024
 
  Angular difference between the analysis and refined position is 0.538452 arcmin
 
  Partial Coding Fraction: 0.2363281    [ including projection effects ]

  Duration
     T90: 21.4679999351501 +/- 3.84755763774157
        Measured from: -1.12800002098083
                   to: 20.3399999141693     [s; relative to TRIGTIME]
     T50: 5.77999991178513 +/- 7.84400228456224
        Measured from: 0.495999991893768
                   to: 6.27599990367889     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.300000011920929     
                   to: 0.699999988079071     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -1.6240000128746     
                   to: 24.0999999642372     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.536009   0.793181   0.370379   0.205111
           0.056045   0.057683   0.050343   0.042397 [error]
 Peak      0.079126   0.160280   0.076247   0.022147
           0.012863   0.014351   0.011685   0.008417 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   25.724   -1.624   24.100
T90    21.468   -1.128   20.340
T50     5.780    0.496    6.276
Peak    1.000   -0.300    0.700
 
 
====== 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      -1.717    -0.163      0.159       -           -               -         4.47e-03     -4.57e-04          4.52e-04      57.870   57
CPL     -1.070    -0.701      0.903       63.491     -16.536       -63.491      1.03e-02     -5.96e-03          2.28e-02      55.550   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      -1.628     -0.183     0.180       -           -               -         2.07e-02     -2.58e-03          2.56e-03      75.460   57
CPL      0.244     -1.130     1.565       53.343      -8.260        18.356      2.26e-01     -2.26e-01          1.44e+00      66.140   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   1.80e-07  2.90e-07  3.52e-07  8.42e-07  1.06e-06  1.66e-06   erg/cm2
      90%_error_low -2.55e-08 -2.71e-08 -4.76e-08 -2.11e-07 -1.13e-07 -2.61e-07   erg/cm2
      90%_error_hi   2.62e-08  2.71e-08  4.78e-08  2.54e-07  1.14e-07  2.93e-07   erg/cm2
Peak flux       PL   9.66e-01  9.01e-01  5.83e-01  5.82e-01  2.69e+00  3.03e+00   ph/cm2/s
      90%_error_low -1.74e-01 -1.12e-01 -8.77e-02 -1.51e-01 -3.27e-01 -3.63e-01   ph/cm2/s
      90%_error_hi   1.81e-01  1.11e-01  8.72e-02  1.78e-01  3.28e-01  3.63e-01   ph/cm2/s
 
Fluence        CPL   1.68e-07  3.14e-07  3.52e-07  3.00e-07  9.97e-07  1.13e-06   erg/cm2
      90%_error_low -2.91e-08 -3.80e-08 -5.65e-08 -2.01e-07 -1.36e-07 -2.44e-07   erg/cm2
      90%_error_hi   2.92e-08  4.01e-08  5.30e-08  6.08e-07  1.36e-07  6.28e-07   erg/cm2
Peak flux      CPL   7.80e-01  1.12e+00  6.16e-01  9.91e-02  2.60e+00  2.61e+00   ph/cm2/s
      90%_error_low -2.12e-01 -1.71e-01 -1.25e-01 -7.16e-02 -3.38e-01 -3.46e-01   ph/cm2/s
      90%_error_hi   2.14e-01  1.80e-01  1.13e-01  1.67e-01  3.36e-01  3.52e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  357.9665    63.0901   0.0122    34.0713    99.8536         1.9677411     15.736 TRIG_00533268                 
 
Foreground time interval of the image:
 -1.624  24.100 (delta_t =  25.724 [sec])
Background time interval of the image:
-85.691  -1.624 (delta_t =  84.067 [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   -1.624 sec. to   24.100 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.71683     ( -0.162762   0.159191 )
Norm@50keV  : 4.46748E-03    ( -0.000457013   0.000451684 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          57.87 using 59 PHA bins.
# Reduced chi-squared =          1.015 for     57 degrees of freedom 
# Null hypothesis probability =   4.428182e-01
 
Photon flux (15-150 keV)    in 25.72 sec: 0.596889 ( -0.056212  0.056257 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.06268e-06 ( -1.12813e-07  1.14065e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -1.624 sec. to   24.100 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.06954     ( -0.700791   0.903193 )
Epeak [keV] : 63.4907      ( -16.5215 -63.4759 )
Norm@50keV  : 1.02609E-02    ( -0.00596507   0.0228319 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          55.55 using 59 PHA bins.
# Reduced chi-squared =         0.9919 for     56 degrees of freedom 
# Null hypothesis probability =   4.919073e-01
 
Photon flux (15-150 keV)    in 25.72 sec: 0.583106 ( -0.058766  0.058499 ) ph/cm2/s
Energy fluence (15-150 keV)             : 9.96578e-07 ( -1.35919e-07  1.36034e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   -0.300 sec. to    0.700 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.62838     ( -0.182805   0.180427 )
Norm@50keV  : 2.07442E-02    ( -0.00257668   0.00256138 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          75.46 using 59 PHA bins.
# Reduced chi-squared =          1.324 for     57 degrees of freedom 
# Null hypothesis probability =   5.136634e-02
 
Photon flux (15-150 keV)    in 1 sec: 2.68977 ( -0.3273  0.32769 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.93397e-07 ( -2.51373e-08  2.52986e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.300 sec. to    0.700 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.243811     ( -1.13386   1.56119 )
Epeak [keV] : 53.3427      ( -8.21983 18.3958 )
Norm@50keV  : 0.226115    ( -0.227938   1.44248 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          66.14 using 59 PHA bins.
# Reduced chi-squared =          1.181 for     56 degrees of freedom 
# Null hypothesis probability =   1.666024e-01
 
Photon flux (15-150 keV)    in 1 sec: 2.60141 ( -0.33826  0.3359 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.71348e-07 ( -2.68207e-08  2.83943e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 21.468 sec.
Hardness ratio (energy fluence ratio) = 1.21691407597

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

S(15-50 keV)  = 4.695616e-07
S(50-150 keV) = 5.931351e-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 = -1.157392562803334E-01, IMY = -6.663447067642172E-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:
-85.691400 -1.624000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 31.1866  68.6732    2.2  24.1   77.9   0.6053   5.2 ------	UNKNOWN                       
268.7684  44.5958    3.1  54.2  171.1   1.5834   3.7 ------	UNKNOWN                       
260.0376  50.4404    2.4  47.6  177.5   0.8944   4.7 ------	UNKNOWN                       

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

Time interval of the image:
-1.624000 24.100000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
357.9665  63.0901    0.7  34.1   99.9   1.9670  15.7 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
556.108590 962.654600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.6009 -40.6368    5.6  55.7 -169.5  -2.1923  -2.1    5.9	Vela X-1                      
170.2169 -60.5401    6.4  38.1  158.2   1.0415   1.8    5.8	Cen X-3                       
186.6509 -62.7958    1.8  34.9  145.7   3.4711   6.5    1.5	GX 301-2                      
244.9831 -15.6433    0.4  39.9   30.0  20.4882  32.7    0.3	Sco X-1                       
212.6614 -33.6105    2.9   8.0   71.7   1.0907   3.9 ------	UNKNOWN                       
167.7587 -33.1577    2.9  31.2 -154.0   1.4303   4.0 ------	UNKNOWN                       
134.7336 -31.6246    4.8  58.8 -159.3   6.2995   2.4 ------	UNKNOWN