GRB090618: 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 15:57:20 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger355083
======================================================================

  Trigger: 00355083      Segment: 000

  BAT Trigger Time: 267006514.688   [s; MET]
      Trigger Stop: 267006515.712   [s; MET]
               UTC: 2009-06-18T08:28:29.851180    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 294.021186499589   Dec: 78.3535968964309  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    22.57
     Image Trigger?:     NO
     Rate S/N Ratio:     85.8370549354997  [ if not an image trigger ]
     Image S/N Ratio:    22.57

  Analysis Position:   [ source = BAT ]
    RA: 294.021186499589   Dec: 78.3535968964309  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 294.00766435887   Dec: 78.3520481276482  [deg; J2000]  
        { 19h 36m 01.8s , +78d 21' 07.4" }
         +/- 0.455445070291291 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.134832402607741 [arcmin] (formal 1-sigma fit error)
    SNR: 93.5549871227227
 
  Angular difference between the analysis and refined position is 0.188319 arcmin
 
  Partial Coding Fraction: 0.625    [ including projection effects ]

  Duration
     T90: 113.340000003576 +/- 0.580344719513611
        Measured from: 10.4560000002384
                   to: 123.796000003815     [s; relative to TRIGTIME]
     T50: 28.0560000240803 +/- 0.160648699669277
        Measured from: 61.0600000023842
                   to: 89.1160000264645     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 65.3840000033379     
                   to: 66.3840000033379     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -4.99599999189377     
                   to: 213.636000007391     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total    50.101114  66.303208  48.856144  11.948221
           0.127355   0.144137   0.131336   0.090757 [error]
 Peak      1.092692   1.691382   1.442514   0.409953
           0.017676   0.021547   0.020909   0.013899 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  218.632   -4.996  213.636
T90   113.340   10.456  123.796
T50    28.056   61.060   89.116
Peak    1.000   65.384   66.384
 
 
====== 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      -1.578    -0.019      0.019       -           -               -         5.33e-02     -6.37e-04          6.35e-04      27.850   57
CPL     -1.488    -0.077      0.078      399.813    -152.049      1709.187      5.73e-02     -3.16e-03          3.72e-03      23.990   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      -1.361     -0.034     0.034       -           -               -         3.22e-01     -5.91e-03          5.90e-03      38.410   57
CPL     -1.235     -0.134     0.138      364.469    -158.572      -364.469      3.63e-01     -3.95e-02          5.11e-02      35.900   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-05  2.80e-05  3.76e-05  1.03e-04  1.09e-04  1.85e-04   erg/cm2
      90%_error_low -4.16e-07 -4.54e-07 -3.74e-07 -2.21e-06 -1.18e-06 -2.21e-06   erg/cm2
      90%_error_hi   4.21e-07  4.54e-07  3.74e-07  2.24e-06  1.18e-06  2.23e-06   erg/cm2
Peak flux       PL   2.73e-03  2.35e-02  3.69e-01  3.16e+01  1.73e+00  1.87e+01   ph/cm2/s
      90%_error_low     N/A       N/A       N/A       N/A       N/A       N/A     ph/cm2/s
      90%_error_hi      N/A       N/A       N/A       N/A       N/A       N/A     ph/cm2/s
 
Fluence        CPL   1.54e-05  2.79e-05  3.80e-05  9.61e-05  1.09e-04  1.78e-04   erg/cm2
      90%_error_low -6.20e-07 -4.65e-07 -5.29e-07 -5.79e-06 -1.21e-06 -5.98e-06   erg/cm2
      90%_error_hi   6.31e-07  4.64e-07  5.30e-07  6.28e-06  1.21e-06  6.45e-06   erg/cm2
Peak flux      CPL   1.11e+01  1.27e+01  1.00e+01  1.13e+01  3.85e+01  4.51e+01   ph/cm2/s
      90%_error_low -6.35e-01 -3.06e-01 -2.47e-01 -1.29e+00 -8.91e-01 -1.70e+00   ph/cm2/s
      90%_error_hi   6.47e-01  3.07e-01  2.48e-01  1.38e+00  8.96e-01  1.65e+00   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  294.0077    78.3520   0.0021    31.1272    23.5813        29.6068669     93.555 TRIG_00355083                 
 
Foreground time interval of the image:
 -4.996  54.613 (delta_t =  59.609 [sec])
Background time interval of the image:
-362.587 -252.614 (delta_t = 109.974 [sec])
-239.688  -4.996 (delta_t = 234.692 [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   -4.996 sec. to  213.636 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.57764     ( -0.018694   0.0187817 )
Norm@50keV  : 5.32807E-02    ( -0.000637106   0.000635569 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          27.85 using 59 PHA bins.
# Reduced chi-squared =         0.4886 for     57 degrees of freedom 
# Null hypothesis probability =   9.995971e-01
 
Photon flux (15-150 keV)    in 218.6 sec: 6.80046 ( -0.10702  0.10755 ) ph/cm2/s
Energy fluence (15-150 keV)             : 0.000109247 ( -1.17585e-06  1.1786e-06 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -4.996 sec. to  213.636 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.48819     ( -0.0772542   0.0784682 )
Epeak [keV] : 399.813      ( -152.015 1709.22 )
Norm@50keV  : 5.73298E-02    ( -0.00316121   0.00372195 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          23.99 using 59 PHA bins.
# Reduced chi-squared =         0.4283 for     56 degrees of freedom 
# Null hypothesis probability =   9.999446e-01
 
Photon flux (15-150 keV)    in 218.6 sec: 6.71788 ( -0.12623  0.12724 ) ph/cm2/s
Energy fluence (15-150 keV)             : 0.000108903 ( -1.20936e-06  1.21037e-06 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   65.384 sec. to   66.384 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.36072     ( -0.0341517   0.0341962 )
Norm@50keV  : 0.321643    ( -0.00590765   0.00590435 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          38.41 using 59 PHA bins.
# Reduced chi-squared =         0.6738 for     57 degrees of freedom 
# Null hypothesis probability =   9.721531e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.73042 (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.1343e-06 ( -5.8274e-08  5.83404e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   65.384 sec. to   66.384 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.23549     ( -0.133637   0.138327 )
Epeak [keV] : 364.469      ( -158.588 -364.485 )
Norm@50keV  : 0.363427    ( -0.0395014   0.0510549 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          35.90 using 59 PHA bins.
# Reduced chi-squared =         0.6410 for     56 degrees of freedom 
# Null hypothesis probability =   9.832452e-01
 
Photon flux (15-150 keV)    in 1 sec: 38.4639 ( -0.8912  0.8958 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.11652e-06 ( -6.15285e-08  6.13783e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 113.34 sec.
Hardness ratio (energy fluence ratio) = 1.34014014571

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

S(15-50 keV)  = 4.403037e-05
S(50-150 keV) = 6.521811e-05

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 = 5.534584737764761E-01, IMY = -2.415850342435254E-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:
-362.587390 -252.613800
-239.688000 -4.996000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
293.9911  78.3562    2.1  31.1   23.6   1.3560   5.4 ------	UNKNOWN                       
 77.6566  45.7715    2.4  41.6  -75.0   4.4677   4.8 ------	UNKNOWN                       

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

Time interval of the image:
-4.996000 54.612600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
261.5602  73.9294    2.4  30.7   40.7   1.5811   4.8 ------	UNKNOWN                       
294.0077  78.3520    0.1  31.1   23.6  29.6050  93.5 ------	UNKNOWN                       
 18.5018  74.5929    2.3  33.0  -11.1   1.3515   5.0 ------	UNKNOWN                       
 77.6977  69.0237    3.3  24.2  -45.6   0.8889   3.5 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
109.612600 962.451700
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
308.0556  41.0438    4.4  37.7   47.5   2.4474   2.6    6.0	Cyg X-3                       
326.0976  38.2683    4.9  42.2   26.5   2.2811   2.3    4.7	Cyg X-2                       
245.7377  42.6655    2.8  40.3  122.9   7.0614   4.1 ------	UNKNOWN                       
284.8316  55.2961    2.5  23.3   78.2   2.6940   4.6 ------	UNKNOWN                       
204.0795  36.5231    2.3  54.4  163.3  13.6347   5.1 ------	UNKNOWN                       
294.0328  78.3342    0.2   0.0   97.4  24.9643  51.5 ------	UNKNOWN