GRB180618A

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 Jul  6 12:10:55 EDT 2018
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger842475
======================================================================

  Trigger: 00842475      Segment: 000

  BAT Trigger Time: 550975414.224   [s; MET]
      Trigger Stop: 550975414.288   [s; MET]
               UTC: 2018-06-18T00:43:13.101380    [includes UTCF correction] 
       Where From?: (*SHORT BURST*) TDRSS scaled map message

  BAT 
    RA: 169.936701156196   Dec: 73.8479030299687  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    9.55
     Image Trigger?:     NO
     Rate S/N Ratio:     43.8406204335659  [ if not an image trigger ]
     Image S/N Ratio:    9.55

  Analysis Position:   [ source = BAT ]
    RA: 169.936701156196   Dec: 73.8479030299687  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 169.944925544303   Dec: 73.8245445189895  [deg; J2000]  
        { 11h 19m 46.8s , +73d 49' 28.4" }
         +/- 1.51060884947347 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.724269622718231 [arcmin] (formal 1-sigma fit error)
    SNR: 16.8727905844673
 
  Angular difference between the analysis and refined position is 1.408227 arcmin
 
  Partial Coding Fraction: 0.703125    [ including projection effects ]

  Duration
     T90: 47.4239999055862 +/- 11.20164564161
        Measured from: 0.00800001621246338
                   to: 47.4319999217987     [s; relative to TRIGTIME]
     T50: 20.607999920845 +/- 11.3426345628471
        Measured from: 0.904000043869019
                   to: 21.5119999647141     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.0759999752044678     
                   to: 0.924000024795532     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.0559999942779541     
                   to: 56.3280000686646     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.344332   0.297032   0.342553   0.071439
           0.048985   0.048040   0.042478   0.037815 [error]
 Peak      0.047750   0.091318   0.104380   0.042081
           0.008194   0.008895   0.009146   0.007705 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   56.384   -0.056   56.328
T90    47.424    0.008   47.432
T50    20.608    0.904   21.512
Peak    1.000   -0.076    0.924
 
 
====== 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      -1.377    -0.266      0.265       -           -               -         1.23e-03     -1.68e-04          1.67e-04      74.850   57
CPL     -1.384    -0.257      0.609     9999.350    -9999.350      -9999.350      1.23e-03     -1.23e-03          -6.20e-04      74.870   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      -0.979     -0.173     0.177       -           -               -         1.87e-02     -1.85e-03          1.84e-03      45.940   57
CPL     -0.969     -0.178     0.666     9981.020    -9981.020      -9981.020      1.89e-02     -1.88e-03          1.78e-02      45.940   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   7.91e-08  1.57e-07  2.41e-07  8.14e-07  6.75e-07  1.29e-06   erg/cm2
      90%_error_low -2.01e-08 -2.39e-08 -4.32e-08 -2.88e-07 -1.03e-07 -3.21e-07   erg/cm2
      90%_error_hi   2.18e-08  2.33e-08  4.22e-08  3.84e-07  1.04e-07  4.01e-07   erg/cm2
Peak flux       PL   4.69e-01  6.44e-01  6.54e-01  1.21e+00  2.15e+00  2.97e+00   ph/cm2/s
      90%_error_low -9.31e-02 -8.05e-02 -7.01e-02 -2.62e-01 -2.15e-01 -3.21e-01   ph/cm2/s
      90%_error_hi   9.97e-02  7.92e-02  6.94e-02  3.07e-01  2.16e-01  3.33e-01   ph/cm2/s
 
Fluence        CPL   7.91e-08  1.57e-07  2.37e-07  8.22e-07  6.79e-07  1.27e-06   erg/cm2
      90%_error_low    N/A       N/A       N/A    -4.77e-07    N/A    -4.44e-07   erg/cm2
      90%_error_hi     N/A       N/A       N/A     1.65e-07    N/A     4.05e-07   erg/cm2
Peak flux      CPL   4.68e-01  6.45e-01  6.56e-01  1.19e+00  2.15e+00  2.97e+00   ph/cm2/s
      90%_error_low -1.16e-01 -7.68e-02 -7.11e-02 -5.78e-01 -2.20e-01 -6.31e-01   ph/cm2/s
      90%_error_hi   7.69e-02  8.42e-02  8.49e-02  1.80e-01  2.16e-01  3.13e-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
  169.9449    73.8245   0.0114    29.7905    20.6860         0.7302472     16.873 TRIG_00842475                 
 
Foreground time interval of the image:
 -0.056   9.077 (delta_t =   9.133 [sec])
Background time interval of the image:
-239.224  -0.056 (delta_t = 239.168 [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   -0.056 sec. to   56.328 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.37712     ( -0.265877   0.264578 )
Norm@50keV  : 1.23322E-03    ( -0.000167555   0.000167033 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          74.85 using 59 PHA bins.
# Reduced chi-squared =          1.313 for     57 degrees of freedom 
# Null hypothesis probability =   5.649312e-02
 
Photon flux (15-150 keV)    in 56.38 sec: 0.149423 ( -0.020925  0.020997 ) ph/cm2/s
Energy fluence (15-150 keV)             : 6.75139e-07 ( -1.02745e-07  1.03875e-07 ) ergs/cm2

Cutoff power-law model

Time interval is from   -0.056 sec. to   56.328 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -3.59894     ( -0.258003   0.608048 )
Epeak [keV] : 401.812      ( -9999.36 -9999.36 )
Norm@50keV  : 1.12729E-04    ( -0.000113308   0.000499455 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          72.93 using 59 PHA bins.
# Reduced chi-squared =          1.302 for     56 degrees of freedom 
# Null hypothesis probability =   6.382077e-02
 
Photon flux (15-150 keV)    in 56.38 sec: 0.149429 ( -0.020957  0.020967 ) ph/cm2/s
Energy fluence (15-150 keV)             : 6.7899e-07 ( 0  0 ) ergs/cm2

1-s peak spectrum fit

Power-law model

Time interval is from   -0.076 sec. to    0.924 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.978647     ( -0.172939   0.177312 )
Norm@50keV  : 1.87269E-02    ( -0.00184947   0.00184358 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          45.94 using 59 PHA bins.
# Reduced chi-squared =         0.8059 for     57 degrees of freedom 
# Null hypothesis probability =   8.527779e-01
 
Photon flux (15-150 keV)    in 1 sec: 2.15380 ( -0.21545  0.21595 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.0408e-07 ( -2.19129e-08  2.20301e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from   -0.076 sec. to    0.924 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.969446     ( -0.177339   0.666754 )
Epeak [keV] : 9981.02      ( -9817.35 -9817.35 )
Norm@50keV  : 1.88792E-02    ( -0.00183715   0.0178274 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          45.94 using 59 PHA bins.
# Reduced chi-squared =         0.8203 for     56 degrees of freedom 
# Null hypothesis probability =   8.290496e-01
 
Photon flux (15-150 keV)    in 1 sec: 2.15258 ( -0.21998  0.21604 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.03915e-07 ( -2.20789e-08  2.09697e-08 ) 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 = 5.355770161809943E-01, IMY = -2.022278593502041E-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:
-239.224000 -0.056000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
  8.2040  77.4659    2.8  51.6   -8.1   2.1409   4.0 ------	UNKNOWN                       
103.1265  12.2964    2.2  46.1 -123.3   5.9589   5.2 ------	UNKNOWN

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

Time interval of the image:
-0.056000 9.076600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
169.9450  73.8246    0.7  29.8   20.7   0.7302  16.9 ------	UNKNOWN                       
137.8565  -9.0339    2.3  56.3 -174.6   0.8579   5.0 ------	UNKNOWN

Post-slew image of 15-350 keV band

Time interval of the image:
65.876610 962.802300
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
174.9005  17.1063    2.8  56.8  173.9  18.2196   4.1 ------	UNKNOWN                       
141.0397  30.0846    2.6  46.2 -145.1   6.4529   4.4 ------	UNKNOWN                       
 71.2723  51.2226    3.8  43.7  -64.1  11.7969   3.0 ------	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