GRB080905A: 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 23:10:40 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger323870
======================================================================

  Trigger: 00323870      Segment: 000

  BAT Trigger Time: 242308738.048   [s; MET]
      Trigger Stop: 242308738.304   [s; MET]
               UTC: 2008-09-05T11:58:54.973940    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 287.661676067797   Dec: -18.8772722987606  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    6.87
     Image Trigger?:     NO
     Rate S/N Ratio:     29.0344622819159  [ if not an image trigger ]
     Image S/N Ratio:    6.87

  Analysis Position:   [ source = BAT ]
    RA: 287.661676067797   Dec: -18.8772722987606  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 287.667070239253   Dec: -18.8666914609386  [deg; J2000]  
        { 19h 10m 40.1s , -18d 52' 00.1" }
         +/- 2.08491945537207 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.764992847180635 [arcmin] (formal 1-sigma fit error)
    SNR: 10.6482085549777
 
  Angular difference between the analysis and refined position is 0.704858 arcmin
 
  Partial Coding Fraction: 0.5625    [ including projection effects ]

  Duration
     T90: 1.01600003242493 +/- 0.0815843255901954
        Measured from: 0.0479999780654907
                   to: 1.06400001049042     [s; relative to TRIGTIME]
     T50: 0.768000036478043 +/- 0.120000004768375
        Measured from: 0.179999977350235
                   to: 0.948000013828278     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.0399999916553497     
                   to: 1.03999999165535     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: 0.0399999916553497     
                   to: 1.12799999117851     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.011610   0.062965   0.065322   0.036225
           0.007346   0.008028   0.007953   0.007170 [error]
 Peak      0.009954   0.056345   0.058198   0.034752
           0.007015   0.007665   0.007648   0.006936 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    1.088    0.040    1.128
T90     1.016    0.048    1.064
T50     0.768    0.180    0.948
Peak    1.000    0.040    1.040
 
 
====== 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      -0.795    -0.233      0.251       -           -               -         1.10e-02     -1.63e-03          1.59e-03      50.300   57
CPL     -0.627    -0.623      1.037      500.017    -500.017      -500.017      1.30e-02     -3.09e-03          2.08e-02      50.200   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      -0.738     -0.250     0.273       -           -               -         1.07e-02     -1.72e-03          1.67e-03      49.120   57
CPL     -0.641     -0.328     1.090      870.906    -870.906      -870.906      1.17e-02     -2.21e-03          1.96e-02      49.090   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   7.96e-09  2.26e-08  5.21e-08  3.24e-07  1.41e-07  4.07e-07   erg/cm2
      90%_error_low -2.34e-09 -4.29e-09 -7.01e-09 -9.13e-08 -1.91e-08 -9.43e-08   erg/cm2
      90%_error_hi   2.63e-09  4.21e-09  6.97e-09  1.17e-07  1.91e-08  1.17e-07   erg/cm2
Peak flux       PL   2.13e-01  3.39e-01  4.06e-01  9.51e-01  1.23e+00  1.91e+00   ph/cm2/s
      90%_error_low -6.91e-02 -7.30e-02 -5.67e-02 -2.61e-01 -1.85e-01 -2.91e-01   ph/cm2/s
      90%_error_hi   7.92e-02  7.21e-02  5.65e-02  3.27e-01  1.87e-01  3.11e-01   ph/cm2/s
 
Fluence        CPL   7.59e-09  2.28e-08  5.33e-08  2.63e-07  1.40e-07  3.46e-07   erg/cm2
      90%_error_low -2.90e-09 -4.41e-09 -7.91e-09 -1.70e-07 -1.97e-08 -1.68e-07   erg/cm2
      90%_error_hi   2.60e-09  4.53e-09  9.27e-09  9.09e-08  1.89e-08  9.11e-08   erg/cm2
Peak flux      CPL   2.07e-01  3.40e-01  4.12e-01  8.66e-01  1.23e+00  1.82e+00   ph/cm2/s
      90%_error_low -8.67e-02 -7.40e-02 -6.14e-02 -4.98e-01 -1.87e-01 -5.37e-01   ph/cm2/s
      90%_error_hi   6.99e-02  7.46e-02  7.78e-02  3.91e-01  1.88e-01  3.66e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  287.6671   -18.8667   0.0181    39.6253    -6.5243         0.1762158     10.648 TRIG_00323870                 
 
Foreground time interval of the image:
  0.040   1.128 (delta_t =   1.088 [sec])
Background time interval of the image:
-749.147 -701.951 (delta_t =  47.196 [sec])
-239.048   0.040 (delta_t = 239.088 [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    0.040 sec. to    1.128 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.794886     ( -0.232794   0.250689 )
Norm@50keV  : 1.10396E-02    ( -0.00162854   0.00158856 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          50.30 using 59 PHA bins.
# Reduced chi-squared =         0.8825 for     57 degrees of freedom 
# Null hypothesis probability =   7.226038e-01
 
Photon flux (15-150 keV)    in 1.088 sec: 1.26903 ( -0.17908  0.18028 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.40678e-07 ( -1.90713e-08  1.91077e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    0.040 sec. to    1.128 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.627066     ( -0.62321   1.03689 )
Epeak [keV] : 500.017      ( -500.159 -500.159 )
Norm@50keV  : 1.29932E-02    ( -0.00309094   0.0207791 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          50.20 using 59 PHA bins.
# Reduced chi-squared =         0.8964 for     56 degrees of freedom 
# Null hypothesis probability =   6.930456e-01
 
Photon flux (15-150 keV)    in 1.088 sec: 1.26279 ( -0.1813  0.18312 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.40058e-07 ( -1.96659e-08  1.89461e-08 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    0.040 sec. to    1.040 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.738146     ( -0.249928   0.272623 )
Norm@50keV  : 1.06965E-02    ( -0.00172456   0.00167041 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          49.12 using 59 PHA bins.
# Reduced chi-squared =         0.8617 for     57 degrees of freedom 
# Null hypothesis probability =   7.617646e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.23308 ( -0.18548  0.18688 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.28381e-07 ( -1.83411e-08  1.83696e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    0.040 sec. to    1.040 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.641058     ( -0.327114   1.09151 )
Epeak [keV] : 870.906      ( -880.934 -880.934 )
Norm@50keV  : 1.17329E-02    ( -0.00219293   0.0196185 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          49.09 using 59 PHA bins.
# Reduced chi-squared =         0.8766 for     56 degrees of freedom 
# Null hypothesis probability =   7.318158e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.22980 ( -0.18743  0.18785 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.28118e-07 ( -1.87249e-08  1.85279e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 1.016 sec.
Hardness ratio (energy fluence ratio) = 2.30557844796

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

S(15-50 keV)  = 3.0565673e-08
S(50-150 keV) = 1.1011144e-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 = 8.226525908598192E-01, IMY = 9.408322069180867E-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:
-749.147400 -701.951500
-239.048000 0.040000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
270.3177 -25.0077   28.7  52.3  -22.9  -0.2000  -0.4    4.7	GX 5-1                        
270.3433 -25.7713    6.1  52.0  -23.8   0.9280   1.9    2.8	GRS 1758-258                  
273.9756 -14.0916    6.1  53.5   -8.6  -0.9896  -1.9    3.7	GX 17+2                       
275.9018 -30.3141    3.7  46.0  -27.7   1.1091   3.2    3.4	H1820-303                     
285.1834 -24.9763    5.4  39.5  -16.8   0.5618   2.1    8.7	HT1900.1-2455                 
  0.3101 -52.9875    2.3  31.8 -138.9   1.1531   5.1 ------	UNKNOWN                       

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

Time interval of the image:
0.040000 1.128000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
270.3121 -25.2938    0.0  52.2  -23.3  -0.0543  -1.8   13.0	GX 5-1                        
270.4466 -25.7473    4.9  51.9  -23.7   0.0684   2.4    7.8	GRS 1758-258                  
273.9731 -14.0226   14.2  53.5   -8.6   0.0259   0.8    2.1	GX 17+2                       
275.9173 -30.2673   13.6  46.0  -27.6   0.0165   0.8    6.0	H1820-303                     
284.9193 -24.9871    5.4  39.8  -16.9   0.0325   2.1    7.5	HT1900.1-2455                 
 28.4955 -22.3963    2.6  52.7  173.1   0.1482   4.5 ------	UNKNOWN                       
287.6671 -18.8667    1.1  39.6   -6.5   0.1762  10.6 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
94.452600 962.978400
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
244.9777 -15.6512    0.9  40.8  -87.5  24.9027  12.4    0.7	Sco X-1                       
255.9144 -37.7923    4.0  33.5 -126.3   1.9060   2.9    4.6	4U 1700-377                   
256.4657 -36.3822    1.4  32.5 -124.2   5.2754   8.1    2.9	GX 349+2                      
263.0138 -24.8204    5.1  23.6 -104.2   1.1876   2.3    4.5	GX 1+4                        
264.9163 -44.5856   11.8  32.0 -143.8   0.5275   1.0   11.0	4U 1735-44                    
268.3629  -1.4420    1.1  25.7  -44.8   4.9142  10.3    0.7	SW J1753.5-0127               
270.3110 -25.0896    1.2  17.3 -109.4   3.8270   9.8    1.6	GX 5-1                        
270.2558 -25.7373    2.8  17.5 -111.4   1.6676   4.2    2.5	GRS 1758-258                  
274.0613 -14.0838    2.7  13.9  -67.1   1.8255   4.3    4.3	GX 17+2                       
275.9486 -30.3227    2.4  15.6 -134.5   1.8855   4.8    2.9	H1820-303                     
285.0024 -24.8518    3.6   6.5 -153.1   1.2571   3.2    4.5	HT1900.1-2455                 
288.7996  10.9520    0.5  29.8    7.0  12.5672  25.0    0.4	GRS 1915+105                  
262.9681 -33.8361    1.6  26.6 -124.4   3.6752   7.1    1.0	GX 354-0                      
282.0408  15.8770    3.6  35.2   -4.6   1.7749   3.2 ------	UNKNOWN                       
277.3167 -23.7832    1.7  10.8 -114.0   2.8978   6.9 ------	UNKNOWN                       
272.4305  22.3529    2.7  43.8  -15.8   3.0446   4.3 ------	UNKNOWN                       
270.0787 -13.1252    3.6  17.9  -69.1   1.4339   3.3 ------	UNKNOWN                       
266.8384 -27.3566    1.5  20.9 -113.0   3.6434   7.7 ------	UNKNOWN                       
255.2011 -41.6439    2.3  35.8 -131.8   3.4721   5.1 ------	UNKNOWN                       
258.7210   2.8784    2.4  35.8  -50.9   3.0206   4.9 ------	UNKNOWN