GRB081118

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 20:44:08 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger334877
======================================================================

  Trigger: 00334877      Segment: 000

  BAT Trigger Time: 248713000   [s; MET]
      Trigger Stop: 248713064   [s; MET]
               UTC: 2008-11-18T14:56:36.734580    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 82.5899853305401   Dec: -43.3021771582674  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    15.02
     Image Trigger?:     YES
     Rate S/N Ratio:     0  [ if not an image trigger ]
     Image S/N Ratio:    15.02

  Analysis Position:   [ source = BAT ]
    RA: 82.5899853305401   Dec: -43.3021771582674  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 82.5739099751729   Dec: -43.3094158966532  [deg; J2000]  
        { 05h 30m 17.7s , -43d 18' 33.9" }
         +/- 1.61666343453725 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.735616264411771 [arcmin] (formal 1-sigma fit error)
    SNR: 15.3140604712617
 
  Angular difference between the analysis and refined position is 0.825397 arcmin
 
  Partial Coding Fraction: 0.6171875    [ including projection effects ]

  Duration
     T90: 53.4040000140667 +/- 12.085376963383
        Measured from: 20.2800000011921
                   to: 73.6840000152588     [s; relative to TRIGTIME]
     T50: 24.8880000114441 +/- 4.24902435662589
        Measured from: 34.5439999997616
                   to: 59.4320000112057     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 46.944000005722     
                   to: 47.944000005722     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: 9.88400000333786     
                   to: 79.83599999547     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.840526   0.809253   0.405292   0.046183
           0.054402   0.056684   0.050249   0.044786 [error]
 Peak      0.023592   0.023637   0.018719   0.007354
           0.006522   0.006816   0.006084   0.005509 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   69.952    9.884   79.836
T90    53.404   20.280   73.684
T50    24.888   34.544   59.432
Peak    1.000   46.944   47.944
 
 
====== 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      -2.108    -0.158      0.151       -           -               -         1.81e-03     -1.85e-04          1.82e-04      62.270   57
CPL     -1.731    -0.382      0.670       29.680     -27.905        39.758      2.98e-03     -1.76e-03          4.25e-03      61.060   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      -1.617     -0.513     0.484       -           -               -         4.68e-03     -1.41e-03          1.36e-03      63.440   57
CPL     -1.198     -1.126     2.685       91.942     -91.942       -91.942      7.78e-03     -7.78e-03          1.58e-01      63.300   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   2.87e-07  3.65e-07  3.39e-07  5.52e-07  1.18e-06  1.54e-06   erg/cm2
      90%_error_low -3.20e-08 -2.86e-08 -4.73e-08 -1.39e-07 -1.08e-07 -1.96e-07   erg/cm2
      90%_error_hi   3.27e-08  2.86e-08  4.82e-08  1.68e-07  1.09e-07  2.17e-07   erg/cm2
Peak flux       PL   2.16e-01  2.03e-01  1.32e-01  1.33e-01  6.05e-01  6.83e-01   ph/cm2/s
      90%_error_low -9.10e-02 -5.82e-02 -5.00e-02 -7.87e-02 -1.69e-01 -1.90e-01   ph/cm2/s
      90%_error_hi   1.01e-01  5.74e-02  4.92e-02  1.26e-01  1.69e-01  1.92e-01   ph/cm2/s
 
Fluence        CPL   2.77e-07  3.81e-07  3.32e-07  2.81e-07  1.13e-06  1.27e-06   erg/cm2
      90%_error_low -3.59e-08 -3.63e-08 -5.40e-08 -1.76e-07 -1.25e-07 -2.25e-07   erg/cm2
      90%_error_hi   3.54e-08  3.85e-08  5.17e-08  4.62e-07  1.28e-07  4.87e-07   erg/cm2
Peak flux      CPL   2.02e-01  2.12e-01  1.36e-01  8.13e-02  5.96e-01  6.31e-01   ph/cm2/s
      90%_error_low -2.02e-01 -6.60e-02 -5.25e-02 -8.13e-02 -1.76e-01 -2.06e-01   ph/cm2/s
      90%_error_hi   1.12e-01  7.48e-02  5.72e-02  8.77e-02  1.74e-01  2.32e-01   ph/cm2/s
 
======================================================================

Special notes of this burst

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
   82.5739   -43.3094   0.0126    38.6517  -170.2407         2.0001983     15.314 TRIG_00334877                 
 
Foreground time interval of the image:
  9.884  73.701 (delta_t =  63.817 [sec])
Background time interval of the image:
-68.699   9.884 (delta_t =  78.583 [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

Bokeh Plot

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    9.884 sec. to   79.836 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.10778     ( -0.158197   0.151397 )
Norm@50keV  : 1.81000E-03    ( -0.000185319   0.000181853 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          62.27 using 59 PHA bins.
# Reduced chi-squared =          1.092 for     57 degrees of freedom 
# Null hypothesis probability =   2.942253e-01
 
Photon flux (15-150 keV)    in 69.95 sec: 0.285883 ( -0.022473  0.022487 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.17746e-06 ( -1.07624e-07  1.09358e-07 ) ergs/cm2

Cutoff power-law model

Time interval is from    9.884 sec. to   79.836 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.73145     ( -0.381898   0.669807 )
Epeak [keV] : 29.6799      ( -27.9058 39.7576 )
Norm@50keV  : 2.98466E-03    ( -0.001762   0.0042531 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          61.06 using 59 PHA bins.
# Reduced chi-squared =          1.090 for     56 degrees of freedom 
# Null hypothesis probability =   2.989902e-01
 
Photon flux (15-150 keV)    in 69.95 sec: 0.281189 ( -0.023605  0.023587 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.13266e-06 ( -1.2485e-07  1.28204e-07 ) ergs/cm2

1-s peak spectrum fit

Power-law model

Time interval is from   46.944 sec. to   47.944 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.61741     ( -0.513158   0.483781 )
Norm@50keV  : 4.68169E-03    ( -0.00141236   0.0013628 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          63.44 using 59 PHA bins.
# Reduced chi-squared =          1.113 for     57 degrees of freedom 
# Null hypothesis probability =   2.599820e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.604929 ( -0.168565  0.169034 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.36999e-08 ( -1.36371e-08  1.40538e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from   46.944 sec. to   47.944 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.19792     ( -1.12558   2.68563 )
Epeak [keV] : 91.9415      ( -91.9806 -91.9806 )
Norm@50keV  : 7.77564E-03    ( -0.00777203   0.158427 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          63.30 using 59 PHA bins.
# Reduced chi-squared =          1.130 for     56 degrees of freedom 
# Null hypothesis probability =   2.344643e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.595528 ( -0.175848  0.1739 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.23292e-08 ( -1.45045e-08  1.50243e-08 ) ergs/cm2

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 53.404 sec.
Hardness ratio (energy fluence ratio) = 0.928047097541

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

S(15-50 keV)  = 6.520128e-07
S(50-150 keV) = 5.254562e-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 = -7.881934631565521E-01, IMY = 1.355677851365692E-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:
-68.699410 9.884000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 86.7707 -12.4857    2.5  44.7  143.1   1.2302   4.6 ------	UNKNOWN

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

Time interval of the image:
9.884000 73.700600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 45.2621   4.9625    2.2  29.8   68.5   0.8296   5.2 ------	UNKNOWN                       
 82.5739 -43.3094    0.8  38.7 -170.2   2.0000  15.3 ------	UNKNOWN                       
 66.6086 -69.4719    2.2  47.4 -131.6   1.9845   5.3 ------	UNKNOWN

Post-slew image of 15-350 keV band

Time interval of the image:
141.500600 963.070800
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.4989 -40.5267    1.1  38.8 -136.4   7.8116  10.3    2.2	Vela X-1                      
 99.7033 -50.4334    2.5  13.7 -113.6   1.8166   4.6 ------	UNKNOWN

Analysis Summary

Notes:

Image

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

Light Curves

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:

Time averaged spectrum fit using the average DRM

Power-law model

Cutoff power-law model

1-s peak spectrum fit

Power-law model

Cutoff power-law model

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

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

Mask shadow pattern

Spacecraft aspect plot

Bright source in the pre-burst/pre-slew/post-slew images

Pre-burst image of 15-350 keV band

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

Post-slew image of 15-350 keV band

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