GRB180805A: 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: Fri Oct 19 18:53:03 EDT 2018
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger851829
======================================================================

  Trigger: 00851829      Segment: 000

  BAT Trigger Time: 555152710.4   [s; MET]
      Trigger Stop: 555152711.424   [s; MET]
               UTC: 2018-08-05T09:04:49.021980    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 167.530004406896   Dec: -45.3308970672546  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.46
     Image Trigger?:     NO
     Rate S/N Ratio:     11.8321595661992  [ if not an image trigger ]
     Image S/N Ratio:    7.46

  Analysis Position:   [ source = BAT ]
    RA: 167.530004406896   Dec: -45.3308970672546  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 167.575257824607   Dec: -45.3266205270777  [deg; J2000]  
        { 11h 10m 18.1s , -45d 19' 35.8" }
         +/- 2.1404842271886 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.944234550083564 [arcmin] (formal 1-sigma fit error)
    SNR: 10.2555353123739
 
  Angular difference between the analysis and refined position is 1.926060 arcmin
 
  Partial Coding Fraction: 0.640625    [ including projection effects ]

  Duration
     T90: 1.67599987983704 +/- 0.408803108661506
        Measured from: 0.116000056266785
                   to: 1.79199993610382     [s; relative to TRIGTIME]
     T50: 0.863999962806702 +/- 0.378227475672485
        Measured from: 0.340000033378601
                   to: 1.2039999961853     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.128000020980835     
                   to: 1.12800002098083     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: 0.0360000133514404     
                   to: 1.89999997615814     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.071355   0.069467   0.047089   0.032694
           0.011993   0.012731   0.011461   0.011116 [error]
 Peak      0.045114   0.053232   0.028976   0.016086
           0.008975   0.009910   0.008758   0.008174 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    1.864    0.036    1.900
T90     1.676    0.116    1.792
T50     0.864    0.340    1.204
Peak    1.000    0.128    1.128
 
 
====== 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      -1.577    -0.322      0.313       -           -               -         6.46e-03     -1.36e-03          1.33e-03      56.430   57
CPL     -0.165    -1.487      2.321       54.082     -14.930       -54.082      4.23e-02     -4.23e-02          9.62e-01      53.880   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      -1.610     -0.341     0.327       -           -               -         8.50e-03     -1.94e-03          1.90e-03      49.950   57
CPL      0.618     -1.986     3.161       47.232     -10.231        61.713      1.73e-01     -1.73e-01          1.20e+01      46.200   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   1.65e-08  2.90e-08  3.88e-08  1.07e-07  1.13e-07  1.91e-07   erg/cm2
      90%_error_low -4.54e-09 -5.53e-09 -1.05e-08 -4.84e-08 -2.52e-08 -6.06e-08   erg/cm2
      90%_error_hi   4.76e-09  5.52e-09  1.07e-08  7.06e-08  2.60e-08  7.89e-08   erg/cm2
Peak flux       PL   3.89e-01  3.67e-01  2.40e-01  2.44e-01  1.10e+00  1.24e+00   ph/cm2/s
      90%_error_low -1.12e-01 -7.51e-02 -6.81e-02 -1.11e-01 -2.23e-01 -2.61e-01   ph/cm2/s
      90%_error_hi   1.18e-01  7.50e-02  6.92e-02  1.57e-01  2.23e-01  2.66e-01   ph/cm2/s
 
Fluence        CPL   1.48e-08  3.44e-08  3.61e-08  1.37e-08  9.57e-08  9.90e-08   erg/cm2
      90%_error_low -5.23e-09 -8.02e-09 -1.57e-08    N/A    -2.59e-08 -2.91e-08   erg/cm2
      90%_error_hi   5.26e-09  8.66e-09  1.33e-08    N/A     3.13e-08  1.09e-07   erg/cm2
Peak flux      CPL   3.24e-01  4.70e-01  2.14e-01  1.98e-02  1.03e+00  1.03e+00   ph/cm2/s
      90%_error_low -1.37e-01 -1.19e-01 -9.96e-02 -1.98e-02 -2.24e-01 -2.25e-01   ph/cm2/s
      90%_error_hi   1.37e-01  1.23e-01  9.45e-02  1.54e-01  2.29e-01  2.40e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  167.5753   -45.3266   0.0187    21.5988   102.3988         0.2538748     10.256 TRIG_00851829                 
 
Foreground time interval of the image:
  0.036   1.900 (delta_t =   1.864 [sec])
Background time interval of the image:
-239.400   0.036 (delta_t = 239.436 [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    0.036 sec. to    1.900 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.57674     ( -0.321812   0.312837 )
Norm@50keV  : 6.45978E-03    ( -0.00135537   0.00133015 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          56.43 using 59 PHA bins.
# Reduced chi-squared =         0.9899 for     57 degrees of freedom 
# Null hypothesis probability =   4.965964e-01
 
Photon flux (15-150 keV)    in 1.864 sec: 0.824271 ( -0.156526  0.156566 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.1295e-07 ( -2.51757e-08  2.60345e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    0.036 sec. to    1.900 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.165453     ( -1.49041   2.31753 )
Epeak [keV] : 54.0818      ( -14.8626 -54.014 )
Norm@50keV  : 4.23430E-02    ( -0.0426594   0.961397 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          53.88 using 59 PHA bins.
# Reduced chi-squared =         0.9621 for     56 degrees of freedom 
# Null hypothesis probability =   5.557057e-01
 
Photon flux (15-150 keV)    in 1.864 sec: 0.784504 ( -0.160172  0.162057 ) ph/cm2/s
Energy fluence (15-150 keV)             : 9.57339e-08 ( -2.58567e-08  3.13105e-08 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    0.128 sec. to    1.128 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.61048     ( -0.340707   0.327057 )
Norm@50keV  : 8.49635E-03    ( -0.00193836   0.00189801 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          49.95 using 59 PHA bins.
# Reduced chi-squared =         0.8763 for     57 degrees of freedom 
# Null hypothesis probability =   7.345108e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.09543 ( -0.222646  0.22266 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.93725e-08 ( -1.90027e-08  1.96742e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    0.128 sec. to    1.128 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.617681     ( -2.01637   3.13074 )
Epeak [keV] : 47.2318      ( -10.0144 61.9306 )
Norm@50keV  : 0.173406    ( -0.186973   11.9823 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          46.20 using 59 PHA bins.
# Reduced chi-squared =         0.8250 for     56 degrees of freedom 
# Null hypothesis probability =   8.218724e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.02583 ( -0.223951  0.22868 ) ph/cm2/s
Energy fluence (15-150 keV)             : 6.30188e-08 ( -1.65213e-08  2.28529e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 1.676 sec.
Hardness ratio (energy fluence ratio) = 1.3408803182

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

S(15-50 keV)  = 4.549833e-08
S(50-150 keV) = 6.745283e-08

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 = -8.500682077132886E-02, IMY = -3.866702760115799E-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:
-239.400000 0.036000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.2952 -40.4460   11.5  26.8  162.1   0.3077   1.0   12.5	Vela X-1                      
170.4064 -60.6214    8.5  36.8  107.4   0.9317   1.4    2.7	Cen X-3                       
193.0344 -49.8972    2.7  35.6   79.1   2.7379   4.3 ------	UNKNOWN                       
125.6439   4.7127    3.2  45.0 -119.3   4.0789   3.7 ------	UNKNOWN                       

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

Time interval of the image:
0.036000 1.900000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.4242 -40.4433   12.3  26.7  162.0  -0.0223  -0.9    8.2	Vela X-1                      
170.5764 -60.6150    4.8  36.8  107.3   0.1155   2.4    7.7	Cen X-3                       
167.5752 -45.3266    1.1  21.6  102.4   0.2539  10.3 ------	UNKNOWN                       
214.6573  -3.7323    2.0  55.6   12.2   0.6257   5.7 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
70.500600 962.667300
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.3317 -40.5446    7.2  23.9 -146.7   1.1444   1.6    9.0	Vela X-1                      
170.4187 -60.6190    2.2  15.4  118.0   4.0723   5.2    3.0	Cen X-3                       
186.6969 -62.7384    1.9  20.6   98.0   5.0345   6.0    2.2	GX 301-2                      
206.0194  -1.6530    3.3  55.2   -7.4   7.0570   3.6 ------	UNKNOWN                       
126.3913 -18.7338    3.8  43.1 -122.4   6.8158   3.0 ------	UNKNOWN