GRB070920B

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 07:11:24 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger291728
======================================================================

  Trigger: 00291728      Segment: 000

  BAT Trigger Time: 212015074.624   [s; MET]
      Trigger Stop: 212015075.648   [s; MET]
               UTC: 2007-09-20T21:04:32.386340    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 0.144108470626363   Dec: -34.8186092179982  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.94
     Image Trigger?:     NO
     Rate S/N Ratio:     14.1067359796659  [ if not an image trigger ]
     Image S/N Ratio:    7.94

  Analysis Position:   [ source = BAT ]
    RA: 0.144108470626363   Dec: -34.8186092179982  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 0.118000545972279   Dec: -34.8455819705286  [deg; J2000]  
        { 00h 00m 28.3s , -34d 50' 44.1" }
         +/- 0.98829579186739 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.410696724987387 [arcmin] (formal 1-sigma fit error)
    SNR: 30.9330499324815
 
  Angular difference between the analysis and refined position is 2.066981 arcmin
 
  Partial Coding Fraction: 1.03125    [ including projection effects ]

  Duration
     T90: 22.2560000121593 +/- 2.79212104121582
        Measured from: -11.2080000042915
                   to: 11.0480000078678     [s; relative to TRIGTIME]
     T50: 9.41200000047684 +/- 1.20058650862768
        Measured from: -4.55200001597404
                   to: 4.85999998450279     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -1.04399999976158     
                   to: -0.0439999997615814     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -14.1200000047684     
                   to: 13.3519999980927     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.491465   0.679196   0.279561   0.050297
           0.024552   0.025822   0.022343   0.019248 [error]
 Peak      0.031941   0.044404   0.020418   0.008319
           0.004850   0.005180   0.004418   0.003793 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   27.472  -14.120   13.352
T90    22.256  -11.208   11.048
T50     9.412   -4.552    4.860
Peak    1.000   -1.044   -0.044
 
 
====== 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      -1.875    -0.094      0.092       -           -               -         3.21e-03     -1.92e-04          1.90e-04      79.010   57
CPL     -0.385    -0.541      0.625       44.717      -3.813         5.192      2.29e-02     -1.17e-02          2.98e-02      51.000   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      -1.667     -0.258     0.250       -           -               -         6.40e-03     -1.01e-03          9.83e-04      54.510   57
CPL     -1.675     -0.251     0.269     9999.270    -9999.260      -9999.270      6.36e-03     -9.77e-04          7.63e-03      54.520   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   1.60e-07  2.35e-07  2.56e-07  5.23e-07  8.11e-07  1.17e-06   erg/cm2
      90%_error_low -1.23e-08 -1.20e-08 -2.07e-08 -8.05e-08 -4.81e-08 -1.02e-07   erg/cm2
      90%_error_hi   1.25e-08  1.20e-08  2.08e-08  8.99e-08  4.86e-08  1.10e-07   erg/cm2
Peak flux       PL   3.09e-01  2.82e-01  1.77e-01  1.71e-01  8.40e-01  9.39e-01   ph/cm2/s
      90%_error_low -6.45e-02 -3.83e-02 -3.67e-02 -6.12e-02 -1.13e-01 -1.32e-01   ph/cm2/s
      90%_error_hi   6.66e-02  3.83e-02  3.68e-02  8.04e-02  1.13e-01  1.33e-01   ph/cm2/s
 
Fluence        CPL   1.39e-07  2.72e-07  2.31e-07  6.69e-08  6.95e-07  7.08e-07   erg/cm2
      90%_error_low -1.45e-08 -1.76e-08 -2.93e-08 -3.28e-08 -5.41e-08 -6.25e-08   erg/cm2
      90%_error_hi   1.46e-08  1.79e-08  2.77e-08  5.88e-08  5.75e-08  7.96e-08   erg/cm2
Peak flux      CPL   3.13e-01  2.77e-01  1.77e-01  1.70e-01  8.44e-01  9.65e-01   ph/cm2/s
      90%_error_low -8.04e-02 -4.07e-02 -4.27e-02     N/A   -1.39e-01 -2.02e-01   ph/cm2/s
      90%_error_hi   7.57e-02  5.36e-02  4.41e-02     N/A    1.31e-01  1.22e-01   ph/cm2/s
 
======================================================================

Special notes of this burst

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
    0.1180   -34.8456   0.0062     7.8147   155.7131         1.6092794     30.933 TRIG_00291728                 
 
Foreground time interval of the image:
-14.120  13.352 (delta_t =  27.472 [sec])
Background time interval of the image:
-105.723 -14.120 (delta_t =  91.603 [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

Bokeh Plot

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  -14.120 sec. to   13.352 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.87483     ( -0.093857   0.0922454 )
Norm@50keV  : 3.21014E-03    ( -0.000191917   0.000190491 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          79.01 using 59 PHA bins.
# Reduced chi-squared =          1.386 for     57 degrees of freedom 
# Null hypothesis probability =   2.844897e-02
 
Photon flux (15-150 keV)    in 27.47 sec: 0.455873 ( -0.023669  0.023685 ) ph/cm2/s
Energy fluence (15-150 keV)             : 8.10791e-07 ( -4.81173e-08  4.85961e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from  -14.120 sec. to   13.352 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.385418     ( -0.541302   0.624621 )
Epeak [keV] : 44.7173      ( -3.81235 5.19255 )
Norm@50keV  : 2.29283E-02    ( -0.0116758   0.0298197 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          51.00 using 59 PHA bins.
# Reduced chi-squared =         0.9107 for     56 degrees of freedom 
# Null hypothesis probability =   6.641043e-01
 
Photon flux (15-150 keV)    in 27.47 sec: 0.426138 ( -0.025418  0.025485 ) ph/cm2/s
Energy fluence (15-150 keV)             : 6.94942e-07 ( -5.40882e-08  5.74755e-08 ) ergs/cm2

1-s peak spectrum fit

Power-law model

Time interval is from   -1.044 sec. to   -0.044 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.66733     ( -0.257682   0.249685 )
Norm@50keV  : 6.39529E-03    ( -0.00101239   0.000983376 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          54.51 using 59 PHA bins.
# Reduced chi-squared =         0.9563 for     57 degrees of freedom 
# Null hypothesis probability =   5.691513e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.839935 ( -0.113452  0.113468 ) ph/cm2/s
Energy fluence (15-150 keV)             : 5.93882e-08 ( -9.86827e-09  1.0127e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from   -1.044 sec. to   -0.044 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.67464     ( -0.251491   0.268549 )
Epeak [keV] : 9999.27      ( -9999.35 -9999.36 )
Norm@50keV  : 6.36494E-03    ( -0.0010041   0.00760374 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          54.52 using 59 PHA bins.
# Reduced chi-squared =         0.9735 for     56 degrees of freedom 
# Null hypothesis probability =   5.311196e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.843952 ( -0.139067  0.131006 ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 22.256 sec.
Hardness ratio (energy fluence ratio) = 0.846681256701

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

S(15-50 keV)  = 4.10988e-07
S(50-150 keV) = 2.8396456e-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 = -1.250973248164751E-01, IMY = -5.644920245335627E-02

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:
-105.723400 -14.120000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
285.0522 -24.9976   14.0  56.8   -6.9   0.3858   0.8    4.7	HT1900.1-2455                 
324.5652  -1.2730    2.2  44.6   50.2   2.2713   5.2 ------	UNKNOWN                       
 58.9484 -63.7931    2.6  46.4 -124.0   1.6872   4.5 ------	UNKNOWN

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

Time interval of the image:
-14.120000 13.352000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
285.0345 -24.8809   12.2  56.9   -6.8   0.2852   1.0    2.4	HT1900.1-2455                 
329.0418 -30.6612    2.4  20.0   16.5   0.2849   4.9 ------	UNKNOWN                       
  0.1180 -34.8456    0.4   7.8  155.7   1.6095  30.9 ------	UNKNOWN

Post-slew image of 15-350 keV band

Time interval of the image:
739.676580 962.490400
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 61.0845   9.9266    2.3  54.9  165.6   4.4443   5.1 ------	UNKNOWN                       
 49.0320   0.0494    2.7  40.0  159.4   1.1621   4.3 ------	UNKNOWN                       
 53.7315  -5.0620    2.4  38.5  170.1   1.0740   4.8 ------	UNKNOWN                       
338.5309 -63.5572    2.5  41.8  -29.2   1.0261   4.7 ------	UNKNOWN

Analysis Summary

Notes:

Image

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

Light Curves

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:

Time averaged spectrum fit using the average DRM

Power-law model

Cutoff power-law model

1-s peak spectrum fit

Power-law model

Cutoff power-law model

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

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

Mask shadow pattern

Spacecraft aspect plot

Bright source in the pre-burst/pre-slew/post-slew images

Pre-burst image of 15-350 keV band

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

Post-slew image of 15-350 keV band

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