GRB070920A: 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 07:16:23 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger291614
======================================================================

  Trigger: 00291614      Segment: 000

  BAT Trigger Time: 211953616   [s; MET]
      Trigger Stop: 211953680   [s; MET]
               UTC: 2007-09-20T04:00:13.763940    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 100.932293960004   Dec: 72.2273663433026  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    10.26
     Image Trigger?:     YES
     Rate S/N Ratio:     0  [ if not an image trigger ]
     Image S/N Ratio:    10.26

  Analysis Position:   [ source = BAT ]
    RA: 100.932293960004   Dec: 72.2273663433026  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 100.971964315622   Dec: 72.242209888389  [deg; J2000]  
        { 06h 43m 53.3s , +72d 14' 32.0" }
         +/- 1.93229129482644 [arcmin] (estimated 90% radius based on SNR)
         +/- 1.17504729485443 [arcmin] (formal 1-sigma fit error)
    SNR: 11.8697956148075
 
  Angular difference between the analysis and refined position is 1.149184 arcmin
 
  Partial Coding Fraction: 1.015625    [ including projection effects ]

  Duration
     T90: 55.7600000202656 +/- 5.28902259694316
        Measured from: 16.8799999952316
                   to: 72.6400000154972     [s; relative to TRIGTIME]
     T50: 32.3160000145435 +/- 10.9756566778799
        Measured from: 24.136000007391
                   to: 56.4520000219345     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 30.4519999921322     
                   to: 31.4519999921322     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: 15.1800000071526     
                   to: 74.8160000145435     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.286194   0.357491   0.205800   0.036111
           0.035464   0.036964   0.032266   0.027751 [error]
 Peak      0.012542   0.019671   0.011123   0.004176
           0.004671   0.004768   0.004208   0.003564 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   59.636   15.180   74.816
T90    55.760   16.880   72.640
T50    32.316   24.136   56.452
Peak    1.000   30.452   31.452
 
 
====== 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      -1.604    -0.213      0.207       -           -               -         9.23e-04     -1.21e-04          1.19e-04      34.060   57
CPL     -1.156    -0.430      0.957       85.928     -40.728       -85.928      1.62e-03     -7.94e-04          3.76e-03      33.120   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      -1.769     -0.587     0.511       -           -               -         2.52e-03     -9.57e-04          9.15e-04      55.010   57
CPL     -0.530      N/A       N/A          52.084      N/A           N/A         1.25e-02        N/A               N/A         53.860   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   7.75e-08  1.34e-07  1.76e-07  4.71e-07  5.15e-07  8.58e-07   erg/cm2
      90%_error_low -1.40e-08 -1.59e-08 -3.08e-08 -1.50e-07 -7.26e-08 -1.82e-07   erg/cm2
      90%_error_hi   1.45e-08  1.59e-08  3.09e-08  1.92e-07  7.40e-08  2.16e-07   erg/cm2
Peak flux       PL   1.35e-01  1.15e-01  6.78e-02  5.95e-02  3.44e-01  3.77e-01   ph/cm2/s
      90%_error_low -5.58e-02 -3.59e-02 -3.14e-02 -3.98e-02 -1.07e-01 -1.20e-01   ph/cm2/s
      90%_error_hi   6.05e-02  3.59e-02  3.27e-02  6.92e-02  1.07e-01  1.23e-01   ph/cm2/s
 
Fluence        CPL   7.36e-08  1.41e-07  1.77e-07  2.24e-07  4.92e-07  6.16e-07   erg/cm2
      90%_error_low -1.59e-08 -2.04e-08 -3.36e-08 -1.59e-07 -8.27e-08 -1.83e-07   erg/cm2
      90%_error_hi   1.60e-08  2.16e-08  3.32e-08  2.98e-07  8.39e-08  3.20e-07   erg/cm2
Peak flux      CPL   1.17e-01  1.34e-01  6.96e-02  1.58e-02  3.33e-01  3.36e-01   ph/cm2/s
      90%_error_low -6.48e-02 -4.56e-02 -6.96e-02 -1.58e-02 -1.06e-01 -1.08e-01   ph/cm2/s
      90%_error_hi   6.72e-02  4.99e-02  3.90e-02  6.55e-02  1.07e-01  1.31e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  100.9720    72.2422   0.0161    14.3977  -153.4907         0.8539508     11.870 TRIG_00291614                 
 
Foreground time interval of the image:
 15.180  74.816 (delta_t =  59.636 [sec])
Background time interval of the image:
-239.000  15.180 (delta_t = 254.180 [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   15.180 sec. to   74.816 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.60367     ( -0.21286   0.207089 )
Norm@50keV  : 9.23291E-04    ( -0.000121303   0.000119317 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          34.06 using 59 PHA bins.
# Reduced chi-squared =         0.5975 for     57 degrees of freedom 
# Null hypothesis probability =   9.931980e-01
 
Photon flux (15-150 keV)    in 59.64 sec: 0.118786 ( -0.014092  0.014096 ) ph/cm2/s
Energy fluence (15-150 keV)             : 5.14823e-07 ( -7.25628e-08  7.39769e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   15.180 sec. to   74.816 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.15647     ( -0.429555   0.957303 )
Epeak [keV] : 85.9277      ( -40.728 -85.9277 )
Norm@50keV  : 1.62044E-03    ( -0.00079369   0.00376114 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          33.12 using 59 PHA bins.
# Reduced chi-squared =         0.5914 for     56 degrees of freedom 
# Null hypothesis probability =   9.936149e-01
 
Photon flux (15-150 keV)    in 59.64 sec: 0.116697 ( -0.014592  0.01456 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.91686e-07 ( -8.27475e-08  8.39099e-08 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   30.452 sec. to   31.452 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.76938     ( -0.587009   0.511168 )
Norm@50keV  : 2.52230E-03    ( -0.000957075   0.000914477 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          55.01 using 59 PHA bins.
# Reduced chi-squared =         0.9651 for     57 degrees of freedom 
# Null hypothesis probability =   5.501029e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.343544 ( -0.106793  0.106794 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.32557e-08 ( -8.58773e-09  9.15586e-09 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   30.452 sec. to   31.452 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.529809     (       )
Epeak [keV] : 52.0836      (   )
Norm@50keV  : 1.24797E-02    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          53.86 using 59 PHA bins.
# Reduced chi-squared =         0.9618 for     56 degrees of freedom 
# Null hypothesis probability =   5.561859e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.333302 ( -0.106131  0.107314 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.11958e-08 ( -8.20637e-09  9.5843e-09 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 55.76 sec.
Hardness ratio (energy fluence ratio) = 1.3161936978

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

S(15-50 keV)  = 2.1118145e-07
S(50-150 keV) = 3.036395e-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 = -2.297229043253134E-01, IMY = 1.145821390813567E-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:
-239.000000 15.180000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6293  22.0143    0.3  37.1   12.1  10.7189  43.3    0.2	Crab                          

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

Time interval of the image:
15.180000 74.816000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.5906  21.8758    4.5  37.3   12.2  -0.3021  -2.6    8.7	Crab                          
 42.8649  32.4538    1.8  39.1   74.7   1.8702   6.4 ------	UNKNOWN                       
345.6086  73.4808    2.4  37.3  160.7   0.5617   4.9 ------	UNKNOWN                       
333.5373  79.1592    2.1  36.3  171.2   0.5315   5.5 ------	UNKNOWN                       
100.9719  72.2423    1.0  14.4 -153.5   0.8550  11.9 ------	UNKNOWN                       
129.9640  38.1034    2.2  34.8  -64.4   0.6259   5.1 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
384.400590 963.078800
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6304  22.0097    0.3  36.7   38.3  23.5197  36.2    0.3	Crab                          
107.8166  69.1893    2.4  19.1  161.6   1.5624   4.8 ------	UNKNOWN                       
123.8451  -7.8927    3.6  58.9  -24.2   7.7268   3.2 ------	UNKNOWN                       
137.9677   3.9832    3.0  50.7  -44.5   7.8491   3.8 ------	UNKNOWN                       
136.7151   2.2464    4.2  51.9  -42.3   5.4485   2.8 ------	UNKNOWN