GRB070721B: 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 20 08:24:06 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger285654
======================================================================

  Trigger: 00285654      Segment: 000

  BAT Trigger Time: 206706828.416   [s; MET]
      Trigger Stop: 206706830.464   [s; MET]
               UTC: 2007-07-21T10:33:46.314280    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 33.1314958399504   Dec: -2.18419461651638  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    8.36
     Image Trigger?:     NO
     Rate S/N Ratio:     12  [ if not an image trigger ]
     Image S/N Ratio:    8.36

  Analysis Position:   [ source = BAT ]
    RA: 33.1314958399504   Dec: -2.18419461651638  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 33.1327948317786   Dec: -2.20076006275162  [deg; J2000]  
        { 02h 12m 31.9s , -02d 12' 02.7" }
         +/- 1.15178840729537 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.3884581262084 [arcmin] (formal 1-sigma fit error)
    SNR: 24.856678201223
 
  Angular difference between the analysis and refined position is 0.996973 arcmin
 
  Partial Coding Fraction: 0.2382812    [ including projection effects ]

  Duration
     T90: 336.863999992609 +/- 22.468004362484
        Measured from: -4.10400000214577
                   to: 332.759999990463     [s; relative to TRIGTIME]
     T50: 269.816000014544 +/- 33.769498957601
        Measured from: 2.62399998307228
                   to: 272.439999997616     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.11599999666214     
                   to: 0.88400000333786     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -6.71200001239777     
                   to: 359.919999986887     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     1.182884   1.675353   1.783700   0.551731
           0.098022   0.103312   0.092489   0.079478 [error]
 Peak      0.020902   0.064539   0.077808   0.035627
           0.009492   0.010631   0.010218   0.008613 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  366.632   -6.712  359.920
T90   336.864   -4.104  332.760
T50   269.816    2.624  272.440
Peak    1.000   -0.116    0.884
 
 
====== 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      -1.237    -0.106      0.107       -           -               -         9.68e-04     -5.66e-05          5.65e-05      58.340   57
CPL     -1.235    -0.104      0.110     9999.350    -9999.350      -9999.350      9.70e-04     -5.43e-05          4.90e-04      58.350   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      -0.835     -0.265     0.287       -           -               -         1.36e-02     -2.31e-03          2.26e-03      49.380   57
CPL     -0.407     -0.557     1.357      224.250    -224.250      -224.250      2.07e-02     -9.03e-03          5.32e-02      48.920   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   3.54e-07  7.65e-07  1.30e-06  5.06e-06  3.56e-06  7.48e-06   erg/cm2
      90%_error_low -4.09e-08 -5.31e-08 -8.96e-08 -7.56e-07 -2.26e-07 -8.10e-07   erg/cm2
      90%_error_hi   4.25e-08  5.26e-08  8.90e-08  8.47e-07  2.26e-07  8.86e-07   erg/cm2
Peak flux       PL   2.98e-01  4.46e-01  5.00e-01  1.06e+00  1.56e+00  2.31e+00   ph/cm2/s
      90%_error_low -9.92e-02 -9.95e-02 -7.81e-02 -3.17e-01 -2.57e-01 -3.80e-01   ph/cm2/s
      90%_error_hi   1.14e-01  9.80e-02  7.78e-02  4.02e-01  2.59e-01  4.00e-01   ph/cm2/s
 
Fluence        CPL   3.57e-07  7.65e-07  1.30e-06  5.09e-06  3.57e-06  7.44e-06   erg/cm2
      90%_error_low -4.37e-08 -4.46e-08 -8.80e-08 -2.28e-06 -1.26e-07 -2.07e-06   erg/cm2
      90%_error_hi   2.61e-08  2.90e-08  5.16e-08  4.62e-07  1.99e-07  4.78e-07   erg/cm2
Peak flux      CPL   2.63e-01  4.54e-01  5.29e-01  7.17e-01  1.54e+00  1.96e+00   ph/cm2/s
      90%_error_low -1.21e-01 -1.05e-01 -9.93e-02 -4.32e-01 -2.61e-01 -5.19e-01   ph/cm2/s
      90%_error_hi   1.37e-01  1.07e-01  1.07e-01  4.63e-01  2.64e-01  5.56e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
   33.1328    -2.2008   0.0078    38.8781  -120.2421         2.9596954     24.857 TRIG_00285654                 
 
Foreground time interval of the image:
 -6.712  24.285 (delta_t =  30.997 [sec])
Background time interval of the image:
-239.416  -6.712 (delta_t = 232.704 [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   -6.712 sec. to  359.920 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.23734     ( -0.105699   0.106818 )
Norm@50keV  : 9.67930E-04    ( -5.65631e-05   5.65397e-05 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          58.34 using 59 PHA bins.
# Reduced chi-squared =          1.024 for     57 degrees of freedom 
# Null hypothesis probability =   4.258726e-01
 
Photon flux (15-150 keV)    in 366.6 sec: 0.114249 ( -0.00704  0.007062 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.56363e-06 ( -2.25584e-07  2.26398e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -6.712 sec. to  359.920 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.23542     ( -0.105226   0.108943 )
Epeak [keV] : 9999.35      ( -9999.36 -9999.36 )
Norm@50keV  : 9.69918E-04    ( -5.67061e-05   0.000488016 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          58.35 using 59 PHA bins.
# Reduced chi-squared =          1.042 for     56 degrees of freedom 
# Null hypothesis probability =   3.890948e-01
 
Photon flux (15-150 keV)    in 366.6 sec: 0.114291 ( -0.007389  0.007001 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.5651e-06 ( -1.26102e-07  1.9892e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   -0.116 sec. to    0.884 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.834882     ( -0.264747   0.286649 )
Norm@50keV  : 1.36194E-02    ( -0.00231336   0.00226004 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          49.38 using 59 PHA bins.
# Reduced chi-squared =         0.8663 for     57 degrees of freedom 
# Null hypothesis probability =   7.532957e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.56378 ( -0.25744  0.25941 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.56884e-07 ( -2.49672e-08  2.50316e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.116 sec. to    0.884 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.406625     ( -0.556925   1.35733 )
Epeak [keV] : 224.250      ( -224.324 -224.324 )
Norm@50keV  : 2.07348E-02    ( -0.0090244   0.0531659 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          48.92 using 59 PHA bins.
# Reduced chi-squared =         0.8736 for     56 degrees of freedom 
# Null hypothesis probability =   7.375100e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.54362 ( -0.26109  0.2638 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.5486e-07 ( -2.64881e-08  2.57659e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 336.864 sec.
Hardness ratio (energy fluence ratio) = 1.69664138367

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

S(15-50 keV)  = 1.119618e-06
S(50-150 keV) = 2.44399e-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 = -4.060807856896126E-01, IMY = 6.965387067634754E-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:
-239.416000 -6.712000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
344.4211 -19.5449    2.9  19.3  120.8   0.6570   4.0 ------	UNKNOWN                       
357.0281 -75.9437    2.5  47.5    9.1   1.4962   4.6 ------	UNKNOWN                       
352.9335 -23.6021    2.6  10.4  123.2   0.6148   4.3 ------	UNKNOWN                       
352.7199   5.8696    2.7  35.9  169.1   0.8903   4.4  560.5	UNKNOWN                       
  3.9048 -65.0427    2.6  36.5    6.5   0.8807   4.5 ------	UNKNOWN                       
 47.5585 -78.8454    2.6  53.8   -2.6   1.9685   4.4 ------	UNKNOWN                       
 73.4583 -78.7466    2.3  58.2   -5.4   4.2847   5.0 ------	UNKNOWN                       
  2.5264  28.7748    2.3  57.3 -173.6   3.7767   5.1 ------	UNKNOWN                       
 18.9627   2.2249    2.8  34.3 -144.1   0.7434   4.1 ------	UNKNOWN                       
 49.1642 -24.1705    2.8  41.2  -78.0   2.6400   4.1 ------	UNKNOWN                       

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

Time interval of the image:
-6.712000 24.284600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 20.9668 -21.2777    2.8  17.7 -103.3   0.2264   4.1 ------	UNKNOWN                       
 25.8489 -23.2063    2.2  21.1  -92.5   0.3180   5.3 ------	UNKNOWN                       
 33.1328  -2.2008    0.5  38.9 -120.2   2.9599  24.9 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
81.484670 542.608200
660.584000 722.646500
840.584000 902.630800
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 33.1283  -2.1793    1.3   0.0  153.2   2.1768   9.1 ------	UNKNOWN                       
 72.5325 -41.0919    2.8  52.6  -16.4   2.6830   4.1 ------	UNKNOWN