GRB180924A: 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 18:10:56 EDT 2018
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger863186
======================================================================

  Trigger: 00863186      Segment: 000

  BAT Trigger Time: 559495364.032   [s; MET]
      Trigger Stop: 559495368.128   [s; MET]
               UTC: 2018-09-24T15:22:22.386320    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 49.1609350574153   Dec: -58.5055477959711  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.17
     Image Trigger?:     NO
     Rate S/N Ratio:     10.4880884817015  [ if not an image trigger ]
     Image S/N Ratio:    7.17

  Analysis Position:   [ source = BAT ]
    RA: 49.1609350574153   Dec: -58.5055477959711  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 49.2098608828787   Dec: -58.5224493217896  [deg; J2000]  
        { 03h 16m 50.4s , -58d 31' 20.8" }
         +/- 1.40435315712517 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.536650982067299 [arcmin] (formal 1-sigma fit error)
    SNR: 18.7256931069874
 
  Angular difference between the analysis and refined position is 1.838236 arcmin
 
  Partial Coding Fraction: 1    [ including projection effects ]

  Duration
     T90: 94.8159999847412 +/- 11.8424247997239
        Measured from: -76.4079999923706
                   to: 18.4079999923706     [s; relative to TRIGTIME]
     T50: 50.9559999704361 +/- 4.49904881592429
        Measured from: -48.4639999866486
                   to: 2.49199998378754     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 2.72800004482269     
                   to: 3.72800004482269     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -84.6679999828339     
                   to: 26.3480000495911     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.999787   1.012354   0.583051   0.058976
           0.061652   0.063441   0.054882   0.047138 [error]
 Peak      0.028997   0.026277   0.023644   0.007910
           0.006235   0.006405   0.005520   0.004630 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  111.016  -84.668   26.348
T90    94.816  -76.408   18.408
T50    50.956  -48.464    2.492
Peak    1.000    2.728    3.728
 
 
====== 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      -1.933    -0.144      0.140       -           -               -         1.33e-03     -1.19e-04          1.17e-04      64.300   57
CPL     -1.785    -0.448      0.557       61.964      N/A           N/A         1.62e-03        N/A               N/A         64.050   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      -1.697     -0.413     0.382       -           -               -         4.65e-03     -1.24e-03          1.19e-03      41.550   57
CPL     -1.086     -1.348     1.931       66.480      N/A           N/A         1.02e-02        N/A               N/A         41.010   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   2.84e-07  4.01e-07  4.20e-07  8.11e-07  1.36e-06  1.92e-06   erg/cm2
      90%_error_low -3.03e-08 -2.86e-08 -5.21e-08 -1.87e-07 -1.17e-07 -2.43e-07   erg/cm2
      90%_error_hi   3.10e-08  2.87e-08  5.28e-08  2.22e-07  1.19e-07  2.71e-07   erg/cm2
Peak flux       PL   2.32e-01  2.07e-01  1.28e-01  1.20e-01  6.18e-01  6.87e-01   ph/cm2/s
      90%_error_low -7.46e-02 -4.71e-02 -4.28e-02 -6.30e-02 -1.40e-01 -1.60e-01   ph/cm2/s
      90%_error_hi   7.90e-02  4.70e-02  4.31e-02  9.37e-02  1.40e-01  1.63e-01   ph/cm2/s
 
Fluence        CPL   2.80e-07  4.08e-07  4.18e-07  6.07e-07  1.34e-06  1.71e-06   erg/cm2
      90%_error_low -3.37e-08 -5.79e-08 -5.53e-08 -3.68e-07 -1.41e-07 -4.05e-07   erg/cm2
      90%_error_hi   3.39e-08  3.74e-08  5.42e-08  2.51e-07  1.13e-07  2.96e-07   erg/cm2
Peak flux      CPL   2.17e-01  2.24e-01  1.31e-01  5.58e-02  6.07e-01  6.27e-01   ph/cm2/s
      90%_error_low -8.55e-02 -5.88e-02 -4.95e-02 -5.58e-02 -1.42e-01 -1.56e-01   ph/cm2/s
      90%_error_hi   8.60e-02  6.44e-02  4.85e-02  8.90e-02  1.42e-01  1.68e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
   49.2099   -58.5224   0.0103     8.1964   145.8958         2.8680448     18.726 TRIG_00863186                 
 
Foreground time interval of the image:
-84.668  26.348 (delta_t = 111.016 [sec])
Background time interval of the image:
-239.032 -84.668 (delta_t = 154.364 [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  -84.668 sec. to   26.348 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.93334     ( -0.144361   0.139737 )
Norm@50keV  : 1.33307E-03    ( -0.000119449   0.000117395 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          64.30 using 59 PHA bins.
# Reduced chi-squared =          1.128 for     57 degrees of freedom 
# Null hypothesis probability =   2.361537e-01
 
Photon flux (15-150 keV)    in 111 sec: 0.194088 ( -0.013936  0.013942 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.36136e-06 ( -1.17152e-07  1.19156e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from  -84.668 sec. to   26.348 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.78511     ( -0.448014   0.557195 )
Epeak [keV] : 61.9635      (   )
Norm@50keV  : 1.61787E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          64.05 using 59 PHA bins.
# Reduced chi-squared =          1.144 for     56 degrees of freedom 
# Null hypothesis probability =   2.148604e-01
 
Photon flux (15-150 keV)    in 111 sec: 0.192641 ( -0.014743  0.014703 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.33737e-06 ( -1.40899e-07  1.13445e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    2.728 sec. to    3.728 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.69736     ( -0.412698   0.381933 )
Norm@50keV  : 4.65356E-03    ( -0.00123752   0.00119157 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          41.55 using 59 PHA bins.
# Reduced chi-squared =         0.7289 for     57 degrees of freedom 
# Null hypothesis probability =   9.381908e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.617500 ( -0.139807  0.139816 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.31023e-08 ( -1.16603e-08  1.21004e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    2.728 sec. to    3.728 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.08553     ( -1.34799   1.93051 )
Epeak [keV] : 66.4798      (   )
Norm@50keV  : 1.02365E-02    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          41.01 using 59 PHA bins.
# Reduced chi-squared =         0.7323 for     56 degrees of freedom 
# Null hypothesis probability =   9.335717e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.607498 ( -0.141569  0.141652 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.08131e-08 ( -1.22964e-08  1.31429e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 94.816 sec.
Hardness ratio (energy fluence ratio) = 1.04732167787

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

S(15-50 keV)  = 6.857465e-07
S(50-150 keV) = 6.756065e-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 = -1.192668647637723E-01, IMY = -8.076260146427267E-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:
-239.032000 -84.668000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
301.3202 -58.7217    2.5  43.2    4.9   1.3705   4.6 ------	UNKNOWN                       
261.5779 -68.7336    2.9  42.5  -24.3   1.1116   3.9 ------	UNKNOWN                       

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

Time interval of the image:
-84.668000 26.348000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 49.2098 -58.5224    0.6   8.2  145.9   2.8681  18.7 ------	UNKNOWN                       
 73.6148 -35.5053    2.1  34.7  177.7   1.1074   5.5 ------	UNKNOWN                       
105.6027 -32.1532    2.5  48.4 -147.1   1.9031   4.6 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
63.268610 635.768610
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 59.6292 -24.6671    2.1  34.7  159.0   3.6551   5.4 ------	UNKNOWN                       
 80.8303 -27.0944    2.5  38.4 -169.0   2.6336   4.7 ------	UNKNOWN                       
338.0697 -80.6568    2.9  29.7  -19.8   1.8319   4.0 ------	UNKNOWN                       
 59.0261 -79.4971    2.5  21.2  -42.8   1.9854   4.7 ------	UNKNOWN                       
 99.1102 -46.1195    3.8  32.0 -128.3   1.5994   3.0 ------	UNKNOWN                       
 97.8221 -16.5671    2.4  55.0 -156.4   8.2549   4.9 ------	UNKNOWN                       
109.5973 -56.5174    3.3  31.4 -104.9   2.3120   3.6 ------	UNKNOWN                       
113.1635 -34.2186    2.5  48.0 -129.1   8.6647   4.6 ------	UNKNOWN