GRB181126A: 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: Mon Dec 17 14:48:09 EST 2018
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger873539
======================================================================

  Trigger: 00873539      Segment: 000

  BAT Trigger Time: 564918870.08   [s; MET]
      Trigger Stop: 564918870.336   [s; MET]
               UTC: 2018-11-26T09:54:08.097180    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 152.350664748836   Dec: -29.6790891415622  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    8.69
     Image Trigger?:     NO
     Rate S/N Ratio:     18.7349939951952  [ if not an image trigger ]
     Image S/N Ratio:    8.69

  Analysis Position:   [ source = BAT ]
    RA: 152.350664748836   Dec: -29.6790891415622  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 152.349677585888   Dec: -29.6979198370686  [deg; J2000]  
        { 10h 09m 23.9s , -29d 41' 52.5" }
         +/- 1.5373525515989 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.590968008458257 [arcmin] (formal 1-sigma fit error)
    SNR: 16.4550472177985
 
  Angular difference between the analysis and refined position is 1.131013 arcmin
 
  Partial Coding Fraction: 0.6875    [ including projection effects ]

  Duration
     T90: 2.09200000762939 +/- 0.118928534389858
        Measured from: 0.0159999132156372
                   to: 2.10799992084503     [s; relative to TRIGTIME]
     T50: 1.6159999370575 +/- 1.09446788754849
        Measured from: 0.307999968528748
                   to: 1.92399990558624     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 1.21799993515015     
                   to: 2.21799993515015     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.0680000782012939     
                   to: 2.16399991512299     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.087321   0.183869   0.161908   0.030544
           0.014499   0.016123   0.014858   0.010863 [error]
 Peak      0.073954   0.125884   0.105323   0.018026
           0.010588   0.012049   0.011198   0.007764 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    2.232   -0.068    2.164
T90     2.092    0.016    2.108
T50     1.616    0.308    1.924
Peak    1.000    1.218    2.218
 
 
====== 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: CPL)
 
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      -1.215    -0.150      0.152       -           -               -         1.45e-02     -1.41e-03          1.41e-03      79.720   57
CPL      0.133    -0.684      0.811       83.827     -14.885        33.613      6.45e-02     -3.35e-02          8.80e-02      66.660   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      -1.320     -0.165     0.164       -           -               -         2.27e-02     -2.35e-03          2.35e-03      53.430   57
CPL     -0.651     -0.629     0.734      106.731     -32.295       524.096      4.83e-02     -2.40e-02          5.87e-02      50.080   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   3.17e-08  6.94e-08  1.20e-07  4.77e-07  3.27e-07  6.97e-07   erg/cm2
      90%_error_low -5.26e-09 -7.51e-09 -1.36e-08 -1.04e-07 -3.47e-08 -1.15e-07   erg/cm2
      90%_error_hi   5.50e-09  7.46e-09  1.35e-08  1.22e-07  3.49e-08  1.30e-07   erg/cm2
Peak flux       PL   7.88e-01  8.82e-01  7.07e-01  9.40e-01  2.72e+00  3.32e+00   ph/cm2/s
      90%_error_low -1.36e-01 -1.00e-01 -8.68e-02 -2.13e-01 -2.85e-01 -3.53e-01   ph/cm2/s
      90%_error_hi   1.43e-01  9.93e-02  8.60e-02  2.45e-01  2.85e-01  3.56e-01   ph/cm2/s
 
Fluence        CPL   2.44e-08  7.85e-08  1.34e-07  1.14e-07  3.06e-07  3.51e-07   erg/cm2
      90%_error_low -6.13e-09 -9.36e-09 -1.65e-08 -5.31e-08 -3.67e-08 -6.26e-08   erg/cm2
      90%_error_hi   6.44e-09  9.62e-09  1.68e-08  1.01e-07  3.70e-08  1.02e-07   erg/cm2
Peak flux      CPL   6.91e-01  9.40e-01  7.63e-01  4.96e-01  2.68e+00  2.89e+00   ph/cm2/s
      90%_error_low -1.62e-01 -1.16e-01 -1.03e-01 -2.25e-01 -2.89e-01 -3.73e-01   ph/cm2/s
      90%_error_hi   1.67e-01  1.20e-01  1.06e-01  4.21e-01  2.89e-01  4.73e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  152.3497   -29.6979   0.0117    26.9457  -128.5901         0.4741824     16.455 TRIG_00873539                 
 
Foreground time interval of the image:
 -0.068   2.164 (delta_t =   2.232 [sec])
Background time interval of the image:
-239.080  -0.068 (delta_t = 239.012 [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   -0.068 sec. to    2.164 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.21521     ( -0.150504   0.152198 )
Norm@50keV  : 1.45134E-02    ( -0.0014126   0.00141258 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          79.72 using 59 PHA bins.
# Reduced chi-squared =          1.399 for     57 degrees of freedom 
# Null hypothesis probability =   2.513459e-02
 
Photon flux (15-150 keV)    in 2.232 sec: 1.70732 ( -0.16993  0.17019 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.27298e-07 ( -3.46578e-08  3.48565e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.068 sec. to    2.164 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.132922     ( -0.683521   0.811265 )
Epeak [keV] : 83.8271      ( -14.8847 33.6126 )
Norm@50keV  : 6.45312E-02    ( -0.0335391   0.0880291 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          66.66 using 59 PHA bins.
# Reduced chi-squared =          1.190 for     56 degrees of freedom 
# Null hypothesis probability =   1.558057e-01
 
Photon flux (15-150 keV)    in 2.232 sec: 1.64173 ( -0.17298  0.17336 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.05902e-07 ( -3.66965e-08  3.69871e-08 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    1.218 sec. to    2.218 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.31996     ( -0.164615   0.164126 )
Norm@50keV  : 2.27417E-02    ( -0.0023532   0.00235041 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          53.43 using 59 PHA bins.
# Reduced chi-squared =         0.9374 for     57 degrees of freedom 
# Null hypothesis probability =   6.096529e-01
 
Photon flux (15-150 keV)    in 1 sec: 2.72340 ( -0.28488  0.28514 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.23681e-07 ( -2.55009e-08  2.56407e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    1.218 sec. to    2.218 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.651049     ( -0.628676   0.733701 )
Epeak [keV] : 106.731      ( -32.295 524.096 )
Norm@50keV  : 4.82578E-02    ( -0.0240064   0.0586988 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          50.08 using 59 PHA bins.
# Reduced chi-squared =         0.8943 for     56 degrees of freedom 
# Null hypothesis probability =   6.973137e-01
 
Photon flux (15-150 keV)    in 1 sec: 2.67826 ( -0.28897  0.28884 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.17305e-07 ( -2.68774e-08  2.67738e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 2.092 sec.
Hardness ratio (energy fluence ratio) = 1.70517852303

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

S(15-50 keV)  = 1.0291807e-07
S(50-150 keV) = 2.0298674e-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 = -3.170698041507865E-01, IMY = 3.973272113535748E-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:
-239.080000 -0.068000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5122 -40.5304    1.1  14.0  -92.7   2.6437  10.2    1.6	Vela X-1                      
 73.0226 -30.4540    3.2  40.5   39.3   2.0701   3.6 ------	UNKNOWN                       
111.9570  -5.4684    2.6  28.5  120.5   1.8469   4.5 ------	UNKNOWN                       
 49.4644 -42.9895    2.6  55.6   16.6   5.9739   4.4 ------	UNKNOWN                       
 87.5702 -63.3271    2.8  37.0  -16.4   1.4348   4.2 ------	UNKNOWN                       

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

Time interval of the image:
-0.068000 2.164000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.7603 -40.5550    4.3  14.2  -93.0   0.0604   2.7   10.6	Vela X-1                      
138.3990 -25.1311    2.1  17.1 -152.6   0.1262   5.6 ------	UNKNOWN                       
152.3497 -29.6979    0.7  26.9 -128.6   0.4741  16.5 ------	UNKNOWN                       
170.5400 -57.6820    2.3  41.5  -78.5   0.4986   5.1 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
59.020600 718.890000
720.920000 962.934600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5347 -40.5578    0.9  17.5   28.9   8.6496  13.1    0.3	Vela X-1                      
170.3462 -60.6179    2.1  33.2  -34.2   4.7884   5.6    0.9	Cen X-3                       
186.5917 -62.6378    6.9  39.7  -42.0   1.9738   1.7    8.1	GX 301-2                      
100.2333 -53.0013    2.9  44.2   24.8   5.5712   4.0 ------	UNKNOWN                       
 87.2583 -64.3355    3.2  52.8   11.4   7.8498   3.6 ------	UNKNOWN                       
150.7784 -17.9411    2.4  11.8  154.7   3.0715   4.9 ------	UNKNOWN                       
 96.2936 -73.3147    3.2  52.1   -0.6   5.3623   3.6 ------	UNKNOWN                       
166.8406 -33.3711    3.6  12.9  -87.8   2.3390   3.2 ------	UNKNOWN                       
171.7100 -12.5078    2.8  24.9 -147.7   3.0195   4.1 ------	UNKNOWN                       
196.1173  -1.4619    4.3  50.2 -134.0  10.1954   2.7 ------	UNKNOWN                       
207.6220 -58.9023    4.0  47.2  -53.5   9.6955   2.9 ------	UNKNOWN