GRB090813: 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 14:33:08 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger359884
======================================================================

  Trigger: 00359884      Segment: 000

  BAT Trigger Time: 271829448.148   [s; MET]
      Trigger Stop: 271829448.212   [s; MET]
               UTC: 2009-08-13T04:10:43.154900    [includes UTCF correction] 
       Where From?: (*SHORT BURST*) TDRSS scaled map message

  BAT 
    RA: 227.017184468102   Dec: 88.572588434289  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.75
     Image Trigger?:     NO
     Rate S/N Ratio:     32.5576411921994  [ if not an image trigger ]
     Image S/N Ratio:    7.75

  Analysis Position:   [ source = BAT ]
    RA: 227.017184468102   Dec: 88.572588434289  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 225.094055131741   Dec: 88.5716313244324  [deg; J2000]  
        { 15h 00m 22.6s , +88d 34' 17.9" }
         +/- 1.30692015386469 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.454301302513962 [arcmin] (formal 1-sigma fit error)
    SNR: 20.7514429676429
 
  Angular difference between the analysis and refined position is 2.875763 arcmin
 
  Partial Coding Fraction: 0.1835938    [ including projection effects ]

  Duration
     T90: 7.14399993419647 +/- 0.565416659857746
        Measured from: -0.163999974727631
                   to: 6.97999995946884     [s; relative to TRIGTIME]
     T50: 5.95999997854233 +/- 0.215295152888328
        Measured from: 0.227999985218048
                   to: 6.18799996376038     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.0400000214576721     
                   to: 0.959999978542328     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.804000020027161     
                   to: 7.32400000095367     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.660525   0.754893   0.559937   0.171106
           0.042693   0.044811   0.039935   0.031660 [error]
 Peak      0.244082   0.344715   0.347778   0.108963
           0.019336   0.022726   0.021628   0.015790 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    8.128   -0.804    7.324
T90     7.144   -0.164    6.980
T50     5.960    0.228    6.188
Peak    1.000   -0.040    0.960
 
 
====== 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      -1.699    -0.117      0.116       -           -               -         1.76e-02     -1.20e-03          1.19e-03      55.160   57
CPL     -1.672    -0.418      0.386      584.495    -584.484      -584.495      1.82e-02     -6.60e-03          1.02e-02      55.190   56
 
 
=== 1-s peak spectral analysis ===
(Best model with acceptable fit: N/A)
 
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      -1.331     -0.114     0.114       -           -               -         7.11e-02     -4.75e-03          4.75e-03      72.250   57
CPL     -1.217     -0.174     0.437      367.478    -367.478      -367.478      8.08e-02     -1.39e-02          4.90e-02      72.030   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   2.21e-07  3.59e-07  4.42e-07  1.07e-06  1.33e-06  2.10e-06   erg/cm2
      90%_error_low -2.35e-08 -2.37e-08 -4.00e-08 -1.93e-07 -9.42e-08 -2.29e-07   erg/cm2
      90%_error_hi   2.42e-08  2.37e-08  3.99e-08  2.20e-07  9.48e-08  2.49e-07   erg/cm2
Peak flux       PL   2.49e+00  2.77e+00  2.20e+00  2.90e+00  8.54e+00  1.04e+01   ph/cm2/s
      90%_error_low -3.04e-01 -2.13e-01 -1.74e-01 -4.50e-01 -5.91e-01 -7.08e-01   ph/cm2/s
      90%_error_hi   3.15e-01  2.11e-01  1.73e-01  4.98e-01  5.92e-01  7.11e-01   ph/cm2/s
 
Fluence        CPL   2.21e-07  3.58e-07  4.41e-07  1.08e-06  1.33e-06  2.12e-06   erg/cm2
      90%_error_low    N/A    -2.34e-08 -4.07e-08    N/A    -1.02e-07 -5.58e-07   erg/cm2
      90%_error_hi     N/A     1.44e-08  4.27e-08    N/A     9.43e-08  1.18e-07   erg/cm2
Peak flux      CPL   1.67e+00  1.13e+00  5.23e-01  4.08e-01  3.50e+00  3.72e+00   ph/cm2/s
      90%_error_low -4.49e-01 -3.07e-01 -1.79e-01 -1.88e-01 -7.61e-01 -6.78e-01   ph/cm2/s
      90%_error_hi   4.25e-01  3.18e-01  1.73e-01  1.76e-01  8.26e-01  8.77e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  225.0941    88.5716   0.0093    41.1401   -56.2264         2.3869696     20.751 TRIG_00359884                 
 
Foreground time interval of the image:
 -0.804   7.324 (delta_t =   8.128 [sec])
Background time interval of the image:
 -8.847  -0.804 (delta_t =   8.043 [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   -0.804 sec. to    7.324 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.69947     ( -0.117479   0.116053 )
Norm@50keV  : 1.76139E-02    ( -0.00119792   0.00118968 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          55.16 using 59 PHA bins.
# Reduced chi-squared =         0.9676 for     57 degrees of freedom 
# Null hypothesis probability =   5.446038e-01
 
Photon flux (15-150 keV)    in 8.128 sec: 2.33899 ( -0.15555  0.15589 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.32579e-06 ( -9.42076e-08  9.4783e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.804 sec. to    7.324 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.67244     ( -0.391838   0.412083 )
Epeak [keV] : 584.495      ( -9996.57 -9996.58 )
Norm@50keV  : 1.81950E-02    ( -0.00605171   0.0107294 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          55.19 using 59 PHA bins.
# Reduced chi-squared =         0.9856 for     56 degrees of freedom 
# Null hypothesis probability =   5.053160e-01
 
Photon flux (15-150 keV)    in 8.128 sec: 2.34023 ( -0.16066  0.15536 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.32667e-06 ( -1.02154e-07  9.42653e-08 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   -0.040 sec. to    0.960 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.33056     ( -0.113727   0.114303 )
Norm@50keV  : 7.11259E-02    ( -0.00475482   0.00475298 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          72.25 using 59 PHA bins.
# Reduced chi-squared =          1.268 for     57 degrees of freedom 
# Null hypothesis probability =   8.394271e-02
 
Photon flux (15-150 keV)    in 1 sec: 8.53524 ( -0.59142  0.59212 ) ph/cm2/s
Energy fluence (15-150 keV)             : 6.97847e-07 ( -5.09279e-08  5.11326e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.040 sec. to    0.960 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.21717     ( -0.174185   0.437539 )
Epeak [keV] : 367.478      ( -367.725 -367.725 )
Norm@50keV  : 8.07669E-02    ( -0.0138462   0.0489807 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          72.03 using 59 PHA bins.
# Reduced chi-squared =          1.286 for     56 degrees of freedom 
# Null hypothesis probability =   7.329674e-02
 
Photon flux (15-150 keV)    in 1 sec: 3.50385 ( -0.76124  0.82645 ) ph/cm2/s
Energy fluence (15-150 keV)             : 6.93777e-07 ( -5.33642e-08  5.25343e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 7.144 sec.
Hardness ratio (energy fluence ratio) = 1.23162938496

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

S(15-50 keV)  = 5.793253e-07
S(50-150 keV) = 7.464699e-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 = 4.856386814430063E-01, IMY = 7.261623316437079E-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:
-8.847400 -0.804000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.3372  35.2871    3.6  22.7 -169.3   0.0870   3.2    6.8	Her X-1                       
288.9072  10.9705    3.8  37.9  110.7   0.2657   3.0    6.6	GRS 1915+105                  
299.6620  35.2103    1.3  19.6   69.2   0.2599   8.6    3.6	Cyg X-1                       
308.2726  40.8720    7.6  21.5   44.4   0.0478   1.5    8.8	Cyg X-3                       
325.9911  38.3361    9.5  34.6   34.4   0.0520   1.2    8.5	Cyg X-2                       

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

Time interval of the image:
-0.804000 7.324000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.2960  35.3979    4.2  22.6 -169.1  -0.1196  -2.7    8.6	Her X-1                       
288.7987  11.1096   12.9  37.7  110.8  -0.1120  -0.9    9.8	GRS 1915+105                  
299.4060  35.2989   20.5  19.4   69.4   0.0260   0.6   10.8	Cyg X-1                       
307.8938  41.0323    7.2  21.2   44.4   0.0732   1.6   10.9	Cyg X-3                       
326.3543  38.3463   34.0  34.8   34.1   0.0225   0.3    8.7	Cyg X-2                       
343.7394  30.3914    2.7  51.1   31.3   0.9062   4.3 ------	UNKNOWN                       
355.7444  57.4601    2.5  44.5   -6.3   0.3147   4.6 ------	UNKNOWN                       
349.1115  73.6778    2.2  38.8  -29.6   0.3507   5.3 ------	UNKNOWN                       
250.0376  62.9303    2.3  22.1  -91.2   0.2519   5.0 ------	UNKNOWN                       
225.0935  88.5716    0.6  41.1  -56.2   2.3870  20.8 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
67.552600 962.917100
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.5449  35.3278    5.3  53.4  157.8   5.8654   2.2    4.4	Her X-1                       
340.0399  50.4534    3.0  40.1   71.2   7.9336   3.8 ------	UNKNOWN                       
320.6169  57.9260    2.7  32.2   89.9   4.1183   4.2 ------	UNKNOWN                       
 47.6820  36.0760    3.9  55.3    5.1   6.4275   3.0 ------	UNKNOWN