GRB080916A: 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 22:35:50 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger324895
======================================================================

  Trigger: 00324895      Segment: 000

  BAT Trigger Time: 243251123.712   [s; MET]
      Trigger Stop: 243251124.736   [s; MET]
               UTC: 2008-09-16T09:45:20.610200    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 336.30162356459   Dec: -57.0218867906394  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    20.32
     Image Trigger?:     NO
     Rate S/N Ratio:     59.9249530663145  [ if not an image trigger ]
     Image S/N Ratio:    20.32

  Analysis Position:   [ source = BAT ]
    RA: 336.30162356459   Dec: -57.0218867906394  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 336.287254898521   Dec: -57.0264865084705  [deg; J2000]  
        { 22h 25m 08.9s , -57d 01' 35.4" }
         +/- 0.608053919213172 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.195430581251631 [arcmin] (formal 1-sigma fit error)
    SNR: 61.9116721932686
 
  Angular difference between the analysis and refined position is 0.544382 arcmin
 
  Partial Coding Fraction: 0.828125    [ including projection effects ]

  Duration
     T90: 61.3479999899864 +/- 6.68005747471514
        Measured from: -0.57600000500679
                   to: 60.7719999849796     [s; relative to TRIGTIME]
     T50: 23.3040000200272 +/- 1.01264012888687
        Measured from: 3.89999997615814
                   to: 27.2039999961853     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 1.25199997425079     
                   to: 2.25199997425079     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -2.40000000596046     
                   to: 88.6399999856949     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     1.893289   2.772831   1.979308   0.397361
           0.048442   0.050464   0.043756   0.035531 [error]
 Peak      0.050762   0.132055   0.128232   0.038723
           0.006106   0.006992   0.006754   0.004902 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   91.040   -2.400   88.640
T90    61.348   -0.576   60.772
T50    23.304    3.900   27.204
Peak    1.000    1.252    2.252
 
 
====== 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      -1.546    -0.046      0.046       -           -               -         5.05e-03     -1.23e-04          1.23e-04      65.290   57
CPL     -1.186    -0.188      0.196      120.957     -24.688        70.431      7.44e-03     -1.33e-03          1.70e-03      54.180   56
 
 
=== 1-s peak 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      -0.925     -0.097     0.099       -           -               -         2.34e-02     -1.39e-03          1.39e-03      55.740   57
CPL     -0.164     -0.422     0.469      138.254     -32.171        96.663      5.12e-02     -1.76e-02          3.01e-02      45.510   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   6.14e-07  1.10e-06  1.50e-06  4.26e-06  4.33e-06  7.47e-06   erg/cm2
      90%_error_low -2.96e-08 -3.07e-08 -4.59e-08 -2.91e-07 -1.11e-07 -3.17e-07   erg/cm2
      90%_error_hi   3.01e-08  3.06e-08  4.59e-08  3.05e-07  1.12e-07  3.28e-07   erg/cm2
Peak flux       PL   5.57e-01  7.91e-01  8.33e-01  1.62e+00  2.69e+00  3.80e+00   ph/cm2/s
      90%_error_low -6.51e-02 -5.85e-02 -5.20e-02 -2.05e-01 -1.60e-01 -2.47e-01   ph/cm2/s
      90%_error_hi   6.79e-02  5.81e-02  5.18e-02  2.23e-01  1.61e-01  2.53e-01   ph/cm2/s
 
Fluence        CPL   5.64e-07  1.12e-06  1.54e-06  2.65e-06  4.22e-06  5.87e-06   erg/cm2
      90%_error_low -3.77e-08 -3.36e-08 -5.06e-08 -5.42e-07 -1.27e-07 -5.55e-07   erg/cm2
      90%_error_hi   3.84e-08  3.38e-08  5.10e-08  7.15e-07  1.26e-07  7.20e-07   erg/cm2
Peak flux      CPL   4.58e-01  8.25e-01  9.10e-01  8.17e-01  2.62e+00  3.01e+00   ph/cm2/s
      90%_error_low -7.99e-02 -6.55e-02 -6.67e-02 -2.36e-01 -1.65e-01 -2.87e-01   ph/cm2/s
      90%_error_hi   8.36e-02  6.61e-02  6.76e-02  3.53e-01  1.65e-01  3.73e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  336.2873   -57.0265   0.0031    18.0139   129.0832         3.4986993     61.912 TRIG_00324895                 
 
Foreground time interval of the image:
 -2.400  15.189 (delta_t =  17.589 [sec])
Background time interval of the image:
-239.712  -2.400 (delta_t = 237.312 [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   -2.400 sec. to   88.640 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.54645     ( -0.0464766   0.0464583 )
Norm@50keV  : 5.05471E-03    ( -0.000123388   0.000123375 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          65.29 using 59 PHA bins.
# Reduced chi-squared =          1.145 for     57 degrees of freedom 
# Null hypothesis probability =   2.107742e-01
 
Photon flux (15-150 keV)    in 91.04 sec: 0.639260 ( -0.017284  0.017335 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.33493e-06 ( -1.11338e-07  1.11607e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -2.400 sec. to   88.640 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.18588     ( -0.188096   0.196426 )
Epeak [keV] : 120.957      ( -24.6883 70.4308 )
Norm@50keV  : 7.44362E-03    ( -0.00132807   0.00169746 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          54.18 using 59 PHA bins.
# Reduced chi-squared =         0.9676 for     56 degrees of freedom 
# Null hypothesis probability =   5.439337e-01
 
Photon flux (15-150 keV)    in 91.04 sec: 0.621877 ( -0.019227  0.019299 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.21845e-06 ( -1.26856e-07  1.26477e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    1.252 sec. to    2.252 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.92528     ( -0.0972489   0.0989347 )
Norm@50keV  : 2.34208E-02    ( -0.00138993   0.00138708 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          55.74 using 59 PHA bins.
# Reduced chi-squared =         0.9778 for     57 degrees of freedom 
# Null hypothesis probability =   5.226172e-01
 
Photon flux (15-150 keV)    in 1 sec: 2.68912 ( -0.16043  0.16059 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.60333e-07 ( -1.64845e-08  1.6546e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    1.252 sec. to    2.252 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.164148     ( -0.421979   0.469172 )
Epeak [keV] : 138.254      ( -32.1711 96.6626 )
Norm@50keV  : 5.12235E-02    ( -0.0176198   0.0300768 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          45.51 using 59 PHA bins.
# Reduced chi-squared =         0.8126 for     56 degrees of freedom 
# Null hypothesis probability =   8.406645e-01
 
Photon flux (15-150 keV)    in 1 sec: 2.62267 ( -0.1648  0.16477 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.51437e-07 ( -1.77525e-08  1.76483e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 61.348 sec.
Hardness ratio (energy fluence ratio) = 1.37331502946

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

S(15-50 keV)  = 1.6846878e-06
S(50-150 keV) = 2.5337235e-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 = -2.050141681261123E-01, IMY = -2.524209043282010E-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:
-239.712000 -2.400000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
256.0019 -37.8310    0.6  37.0  -28.8   4.7117  19.6    1.1	4U 1700-377                   
256.2778 -36.4991    4.8  38.0  -27.3   0.5825   2.4    8.9	GX 349+2                      
263.1052 -24.5968    7.7  45.8  -11.1   0.4862   1.5   10.4	GX 1+4                        
264.8892 -44.5516    7.8  27.7  -25.7   0.2450   1.5    8.7	4U 1735-44                    
270.4477 -25.1874    0.0  42.8   -2.6  -0.0904  -0.3   11.0	GX 5-1                        
270.3084 -25.6717    4.7  42.3   -3.0   0.6931   2.4    4.3	GRS 1758-258                  
274.0624 -13.9854    5.7  52.4    6.5   1.1157   2.0    4.5	GX 17+2                       
275.9252 -30.3661    9.6  36.2    1.7   0.2658   1.2    0.1	H1820-303                     
285.0451 -24.9603    3.0  39.2   16.9   0.9483   3.8    2.4	HT1900.1-2455                 
263.1264 -33.7611    5.3  37.6  -17.1   0.4802   2.2    8.1	GX 354-0                      
  2.1619 -60.4692    2.4  27.9  154.5   1.0944   4.9 ------	UNKNOWN                       
248.0079 -48.8114    2.1  32.0  -48.9   1.2121   5.5 ------	UNKNOWN                       
222.5218 -56.5494    3.8  38.0  -77.3   1.6373   3.0 ------	UNKNOWN                       
203.7699 -62.3465    2.8  40.8  -94.2   3.7127   4.1 ------	UNKNOWN                       

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

Time interval of the image:
-2.400000 15.188600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
256.1451 -37.9593    7.3  36.8  -28.7   0.1085   1.6   10.2	4U 1700-377                   
256.3712 -36.5224    4.3  37.9  -27.2   0.1955   2.7    6.7	GX 349+2                      
262.9127 -24.8985    5.6  45.6  -11.5   0.1896   2.1   10.6	GX 1+4                        
264.7330 -44.4445   63.1  27.8  -25.7  -0.0106  -0.2    0.5	4U 1735-44                    
270.1745 -25.1307   14.3  42.9   -2.9   0.0670   0.8    6.7	GX 5-1                        
270.2031 -25.8317    4.1  42.2   -3.3   0.2287   2.8    7.6	GRS 1758-258                  
274.0256 -13.9574    6.8  52.4    6.5   0.2780   1.7    4.9	GX 17+2                       
276.0431 -30.3905   15.6  36.2    1.9  -0.0538  -0.7    6.3	H1820-303                     
285.1033 -24.9245    5.3  39.2   17.0  -0.1864  -2.2    3.7	HT1900.1-2455                 
262.9617 -33.7693   11.9  37.6  -17.3   0.0697   1.0    4.2	GX 354-0                      
336.2873 -57.0265    0.2  18.0  129.1   3.4981  61.9 ------	UNKNOWN                       
 78.8561 -65.4449    2.4  48.2 -161.2   0.5240   4.9 ------	UNKNOWN                       
239.4445 -26.5998    2.0  53.9  -37.2   1.4231   6.0 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
54.388610 962.302100
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
264.6746 -44.4602    6.8  44.7  -37.5   1.1922   1.7    3.0	4U 1735-44                    
270.2241 -25.0690    7.0  56.2  -16.3   2.3636   1.6    3.3	GX 5-1                        
270.3392 -25.6962    3.1  55.7  -16.6   5.0488   3.8    3.4	GRS 1758-258                  
275.9172 -30.3554    3.3  49.0  -15.3   2.5665   3.5    0.8	H1820-303                     
284.9267 -24.8991   18.2  48.6   -2.5  -0.5008  -0.6    6.1	HT1900.1-2455                 
262.9822 -33.8042    6.2  53.4  -29.0   2.2642   1.9    1.9	GX 354-0                      
292.4287 -35.3821    2.5  36.3   -4.1   2.3374   4.6 ------	UNKNOWN                       
238.6785 -68.1342    3.1  41.3  -77.6   7.1500   3.8 ------	UNKNOWN