GRB081024A: 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 21:26:21 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger332516
======================================================================

  Trigger: 00332516      Segment: 000

  BAT Trigger Time: 246520392.064   [s; MET]
      Trigger Stop: 246520392.192   [s; MET]
               UTC: 2008-10-24T05:53:08.864600    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 27.8984760230204   Dec: 61.3465228980006  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    9.9
     Image Trigger?:     NO
     Rate S/N Ratio:     29.4788059459674  [ if not an image trigger ]
     Image S/N Ratio:    9.9

  Analysis Position:   [ source = BAT ]
    RA: 27.8984760230204   Dec: 61.3465228980006  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 27.8893826908972   Dec: 61.3537443873605  [deg; J2000]  
        { 01h 51m 33.5s , +61d 21' 13.5" }
         +/- 1.65276963177235 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.76410122260265 [arcmin] (formal 1-sigma fit error)
    SNR: 14.838379967615
 
  Angular difference between the analysis and refined position is 0.506132 arcmin
 
  Partial Coding Fraction: 0.9765625    [ including projection effects ]

  Duration
     T90: 1.82400000095367 +/- 0.586051204050593
        Measured from: -1.6240000128746
                   to: 0.199999988079071     [s; relative to TRIGTIME]
     T50: 0.656000018119812 +/- 0.332415418371665
        Measured from: -0.592000007629395
                   to: 0.0640000104904175     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.732000023126602     
                   to: 0.267999976873398     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -1.65600001811981     
                   to: 0.267999976873398     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.038974   0.065417   0.055679   0.026605
           0.006791   0.007191   0.006584   0.005669 [error]
 Peak      0.029996   0.052304   0.042152   0.023384
           0.005000   0.005465   0.005115   0.004337 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    1.924   -1.656    0.268
T90     1.824   -1.624    0.200
T50     0.656   -0.592    0.064
Peak    1.000   -0.732    0.268
 
 
====== 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: 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      -1.106    -0.205      0.212       -           -               -         6.32e-03     -7.21e-04          7.20e-04      81.600   57
CPL     -1.108    -0.200      0.221     9999.360    -9999.360      -9999.360      6.34e-03     -6.34e-03          4.43e-03      81.620   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      -1.077     -0.205     0.212       -           -               -         9.39e-03     -1.06e-03          1.06e-03      66.320   57
CPL     -1.074     -0.204     0.216     9999.360    -9999.360      -9999.360      9.44e-03     -9.44e-03          4.47e-03      66.350   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   1.07e-08  2.52e-08  4.67e-08  2.09e-07  1.27e-07  2.92e-07   erg/cm2
      90%_error_low -2.40e-09 -3.44e-09 -6.30e-09 -5.78e-08 -1.61e-08 -6.22e-08   erg/cm2
      90%_error_hi   2.55e-09  3.36e-09  6.21e-09  7.30e-08  1.62e-08  7.53e-08   erg/cm2
Peak flux       PL   2.58e-01  3.34e-01  3.17e-01  5.32e-01  1.09e+00  1.44e+00   ph/cm2/s
      90%_error_low -5.84e-02 -4.71e-02 -4.08e-02 -1.37e-01 -1.25e-01 -1.76e-01   ph/cm2/s
      90%_error_hi   6.25e-02  4.59e-02  4.02e-02  1.67e-01  1.26e-01  1.82e-01   ph/cm2/s
 
Fluence        CPL   1.07e-08  2.52e-08  4.60e-08  2.26e-07  1.28e-07  2.90e-07   erg/cm2
      90%_error_low    N/A       N/A       N/A    -1.29e-07    N/A    -1.11e-07   erg/cm2
      90%_error_hi     N/A       N/A       N/A     1.34e-08    N/A     3.46e-08   erg/cm2
Peak flux      CPL   2.58e-01  3.34e-01  3.17e-01  5.28e-01  1.09e+00  1.45e+00   ph/cm2/s
      90%_error_low     N/A   -4.76e-02 -4.08e-02     N/A   -1.25e-01 -2.35e-01   ph/cm2/s
      90%_error_hi      N/A    4.68e-02  4.03e-02     N/A    1.26e-01  1.78e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
   27.8894    61.3537   0.0130    19.4050    -7.6971         0.1934305     14.838 TRIG_00332516                 
 
Foreground time interval of the image:
 -1.656   0.268 (delta_t =   1.924 [sec])
Background time interval of the image:
-239.064  -1.656 (delta_t = 237.408 [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   -1.656 sec. to    0.268 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.10608     ( -0.205145   0.211978 )
Norm@50keV  : 6.31680E-03    ( -0.000721074   0.000719764 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          81.60 using 59 PHA bins.
# Reduced chi-squared =          1.432 for     57 degrees of freedom 
# Null hypothesis probability =   1.798267e-02
 
Photon flux (15-150 keV)    in 1.924 sec: 0.733143 ( -0.085936  0.086142 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.26837e-07 ( -1.60635e-08  1.61958e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -1.656 sec. to    0.268 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.10817     ( -0.200339   0.220044 )
Epeak [keV] : 9999.36      ( -9999.36 -9999.36 )
Norm@50keV  : 6.33674E-03    ( -0.00635136   0.00441936 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          81.62 using 59 PHA bins.
# Reduced chi-squared =          1.457 for     56 degrees of freedom 
# Null hypothesis probability =   1.434401e-02
 
Photon flux (15-150 keV)    in 1.924 sec: 0.738589 ( -0.091511  0.080495 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.28486e-07 ( 0  0 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   -0.732 sec. to    0.268 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.07705     ( -0.205095   0.211809 )
Norm@50keV  : 9.39096E-03    ( -0.00105845   0.00105556 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          66.32 using 59 PHA bins.
# Reduced chi-squared =          1.163 for     57 degrees of freedom 
# Null hypothesis probability =   1.865151e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.08699 ( -0.125263  0.12561 ) ph/cm2/s
Energy fluence (15-150 keV)             : 9.89259e-08 ( -1.24211e-08  1.25138e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.732 sec. to    0.268 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.07438     ( -0.204197   0.215503 )
Epeak [keV] : 9999.36      ( -9999.36 -9999.36 )
Norm@50keV  : 9.44274E-03    ( -0.00944266   0.00447354 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          66.35 using 59 PHA bins.
# Reduced chi-squared =          1.185 for     56 degrees of freedom 
# Null hypothesis probability =   1.621743e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.08678 ( -0.125368  0.12553 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.23877e-08 ( 0  0 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = N/A sec.
Hardness ratio (energy fluence ratio) = N/A

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

S(15-50 keV)  = N/A
S(50-150 keV) = N/A

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 = 3.490792835708678E-01, IMY = 4.717955129490216E-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:
-239.064000 -1.656000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
299.5924  35.1990    0.4  43.4 -145.1   9.6949  30.4    0.2	Cyg X-1                       
308.1368  40.9505    4.3  34.6 -144.4   0.5788   2.7    1.2	Cyg X-3                       
326.1262  38.3321    3.0  25.2 -165.9   0.6565   3.9    2.2	Cyg X-2                       
327.6488   3.5298    3.0  54.0  161.1   4.0275   3.9 ------	UNKNOWN                       
 72.0904  41.4136    3.5  50.4   14.4   1.7854   3.4 ------	UNKNOWN                       
 53.7233  53.1844    1.7  33.8    8.6   1.4054   6.8 ------	UNKNOWN                       
 95.7514  52.3387    3.0  55.8   -9.0   2.3276   3.8 ------	UNKNOWN                       
315.7480  48.3460    2.8  26.2 -136.9   0.7980   4.2 ------	UNKNOWN                       

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

Time interval of the image:
-1.656000 0.268000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
299.7502  35.2635   84.3  43.2 -145.1  -0.0035  -0.1    8.7	Cyg X-1                       
307.9284  40.9520   21.9  34.7 -144.3   0.0092   0.5    8.2	Cyg X-3                       
326.1786  38.2239    4.3  25.2 -166.1   0.0362   2.7    5.9	Cyg X-2                       
333.1788  18.4963    2.1  38.1  162.1   0.1143   5.6 ------	UNKNOWN                       
 27.8894  61.3538    0.8  19.4   -7.7   0.1934  14.8 ------	UNKNOWN                       
355.3607  64.7256    2.2  13.0  -58.6   0.0675   5.2 ------	UNKNOWN                       
309.1709  50.1869    2.6  29.5 -129.7   0.0746   4.4 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
56.436600 963.021000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
299.5936  35.1914    1.9  58.9 -161.0  23.8417   6.1    0.6	Cyg X-1                       
308.1764  40.8773    3.4  50.3 -163.6   3.7345   3.4    5.4	Cyg X-3                       
326.2125  38.4592   10.3  43.6  179.4   0.8184   1.1    8.5	Cyg X-2                       
  9.0760  42.8395    2.8  21.6  131.6   1.9246   4.1 ------	UNKNOWN                       
 53.7801  53.1745    0.9  16.0   20.5   5.6836  13.6 ------	UNKNOWN                       
345.1585  56.4311    2.9  22.2 -171.8   1.6396   3.9 ------	UNKNOWN                       
262.2471  70.1089    3.5  43.1 -112.2   7.9066   3.3 ------	UNKNOWN