GRB090912: 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 14:07:55 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger362633
======================================================================

  Trigger: 00362633      Segment: 000

  BAT Trigger Time: 274463434.944   [s; MET]
      Trigger Stop: 274463435.968   [s; MET]
               UTC: 2009-09-12T15:50:29.864660    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 188.091869580758   Dec: 61.5125700544948  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    6.62
     Image Trigger?:     NO
     Rate S/N Ratio:     10.4880884817015  [ if not an image trigger ]
     Image S/N Ratio:    6.62

  Analysis Position:   [ source = BAT ]
    RA: 188.091869580758   Dec: 61.5125700544948  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 188.049116055693   Dec: 61.4772951921945  [deg; J2000]  
        { 12h 32m 11.8s , +61d 28' 38.3" }
         +/- 1.17822711732731 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.324340065226452 [arcmin] (formal 1-sigma fit error)
    SNR: 24.0637133602529
 
  Angular difference between the analysis and refined position is 2.445043 arcmin
 
  Partial Coding Fraction: 0.3046875    [ including projection effects ]

  Duration
     T90: 135.51599997282 +/- 15.672510959608
        Measured from: 0.923999965190887
                   to: 136.439999938011     [s; relative to TRIGTIME]
     T50: 70.8679999113083 +/- 11.0586545187354
        Measured from: 28.4480000138283
                   to: 99.3159999251366     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 88.1520000100136     
                   to: 89.1520000100136     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -2.96799999475479     
                   to: 159.103999972343     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     2.198214   3.139636   2.057023   0.226923
           0.124654   0.131316   0.117345   0.104166 [error]
 Peak      0.064335   0.054791   0.048806   0.016097
           0.010947   0.011213   0.009853   0.008475 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  162.072   -2.968  159.104
T90   135.516    0.924  136.440
T50    70.868   28.448   99.316
Peak    1.000   88.152   89.152
 
 
====== 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: CPL)
 
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      -1.679    -0.092      0.091       -           -               -         3.17e-03     -1.71e-04          1.70e-04      54.030   57
CPL     -0.961    -0.399      0.441       69.126     -11.006        28.535      7.47e-03     -2.78e-03          5.09e-03      43.880   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      -1.840     -0.385     0.356       -           -               -         1.04e-02     -2.45e-03          2.31e-03      71.450   57
CPL     -1.858     -0.369     0.707     9999.360      N/A           N/A         1.03e-02        N/A               N/A         71.460   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   7.76e-07  1.28e-06  1.60e-06  3.96e-06  4.76e-06  7.61e-06   erg/cm2
      90%_error_low -6.51e-08 -6.70e-08 -1.15e-07 -5.69e-07 -2.71e-07 -6.71e-07   erg/cm2
      90%_error_hi   6.67e-08  6.69e-08  1.15e-07  6.29e-07  2.73e-07  7.18e-07   erg/cm2
Peak flux       PL   5.93e-01  4.88e-01  2.73e-01  2.25e-01  1.45e+00  1.58e+00   ph/cm2/s
      90%_error_low -1.67e-01 -9.16e-02 -8.34e-02 -1.11e-01 -2.73e-01 -3.01e-01   ph/cm2/s
      90%_error_hi   1.74e-01  9.15e-02  8.34e-02  1.62e-01  2.73e-01  3.03e-01   ph/cm2/s
 
Fluence        CPL   6.93e-07  1.37e-06  1.63e-06  1.46e-06  4.48e-06  5.16e-06   erg/cm2
      90%_error_low -7.82e-08 -8.44e-08 -1.27e-07 -5.65e-07 -3.10e-07 -6.43e-07   erg/cm2
      90%_error_hi   7.94e-08  8.61e-08  1.27e-07  9.80e-07  3.12e-07  1.01e-06   erg/cm2
Peak flux      CPL   6.00e-01  4.85e-01  2.69e-01  2.24e-01  1.46e+00  1.57e+00   ph/cm2/s
      90%_error_low -9.00e-02 -8.83e-02 -1.72e-01     N/A   -2.81e-01 -1.56e-01   ph/cm2/s
      90%_error_hi   1.74e-01  9.71e-02  2.57e-02     N/A    2.67e-01  3.03e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  188.0491    61.4773   0.0080    33.9198  -104.9774         8.3336707     24.064 TRIG_00362633                 
 
Foreground time interval of the image:
 -2.968 159.104 (delta_t = 162.072 [sec])
Background time interval of the image:
-239.944  -2.968 (delta_t = 236.976 [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   -2.968 sec. to  159.104 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.67882     ( -0.0919559   0.0909684 )
Norm@50keV  : 3.16760E-03    ( -0.000171242   0.000170453 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          54.03 using 59 PHA bins.
# Reduced chi-squared =         0.9479 for     57 degrees of freedom 
# Null hypothesis probability =   5.871863e-01
 
Photon flux (15-150 keV)    in 162.1 sec: 0.417645 ( -0.021951  0.021984 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.76324e-06 ( -2.71004e-07  2.72608e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -2.968 sec. to  159.104 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.961076     ( -0.398639   0.441266 )
Epeak [keV] : 69.1265      ( -11.0062 28.5345 )
Norm@50keV  : 7.46930E-03    ( -0.00278415   0.00509137 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          43.88 using 59 PHA bins.
# Reduced chi-squared =         0.7836 for     56 degrees of freedom 
# Null hypothesis probability =   8.801393e-01
 
Photon flux (15-150 keV)    in 162.1 sec: 0.402107 ( -0.023464  0.023474 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.47871e-06 ( -3.09699e-07  3.12034e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   88.152 sec. to   89.152 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.84009     ( -0.385057   0.356352 )
Norm@50keV  : 1.03803E-02    ( -0.00245187   0.00231256 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          71.45 using 59 PHA bins.
# Reduced chi-squared =          1.254 for     57 degrees of freedom 
# Null hypothesis probability =   9.425356e-02
 
Photon flux (15-150 keV)    in 1 sec: 1.45330 ( -0.27305  0.2731 ) ph/cm2/s
Energy fluence (15-150 keV)             : 9.54751e-08 ( -2.18035e-08  2.23832e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   88.152 sec. to   89.152 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.858     ( -0.370415   0.70621 )
Epeak [keV] : 9999.36      (   )
Norm@50keV  : 1.03135E-02    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          71.46 using 59 PHA bins.
# Reduced chi-squared =          1.276 for     56 degrees of freedom 
# Null hypothesis probability =   7.978648e-02
 
Photon flux (15-150 keV)    in 1 sec: 1.46164 ( -0.28115  0.26667 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.71649e-08 ( -3.44007e-08  4.11801e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 135.516 sec.
Hardness ratio (energy fluence ratio) = 1.18918615239

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

S(15-50 keV)  = 2.0637513e-06
S(50-150 keV) = 2.4149483e-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 = -1.737931135051386E-01, IMY = 6.496288124449586E-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:
-239.944000 -2.968000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
308.2922  40.9015    7.0  48.7  143.5   1.4140   1.7    8.8	Cyg X-3                       
134.4172  44.5763    2.9  46.9  -53.1   3.6752   4.0 ------	UNKNOWN                       

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

Time interval of the image:
-2.968000 159.104000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
308.2460  40.8779    9.1  48.8  143.5  -1.0686  -1.3    7.6	Cyg X-3                       
 47.7693  74.9555    2.6   9.6   29.6   0.7510   4.5 ------	UNKNOWN                       
230.4959  49.9496    2.6  45.6 -141.9   1.7247   4.4 ------	UNKNOWN                       
188.0491  61.4773    0.5  33.9 -105.0   8.3341  24.1 ------	UNKNOWN                       
112.7112  32.7415    2.3  56.5  -29.8   5.4705   5.1 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
360.056000 695.756600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6418  22.0137    0.7  37.5   73.9  13.3612  17.5    0.5	Crab                          
103.5834 -18.8404    2.1  54.2   12.9   5.7952   5.4 ------	UNKNOWN                       
138.9332 -16.4212    3.1  49.8  -30.0   2.2859   3.7 ------	UNKNOWN                       
153.6353  -6.5352    3.5  47.1  -53.1   4.4516   3.3 ------	UNKNOWN