GRB180224A

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: Thu Apr  5 17:40:40 EDT 2018
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger811561
======================================================================

  Trigger: 00811561      Segment: 000

  BAT Trigger Time: 541203688.256   [s; MET]
      Trigger Stop: 541203689.28   [s; MET]
               UTC: 2018-02-24T22:21:07.725300    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 202.661007449936   Dec: 38.088104423003  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    10.08
     Image Trigger?:     NO
     Rate S/N Ratio:     16.3095064303001  [ if not an image trigger ]
     Image S/N Ratio:    10.08

  Analysis Position:   [ source = BAT ]
    RA: 202.661007449936   Dec: 38.088104423003  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 202.672214834606   Dec: 38.0750423735811  [deg; J2000]  
        { 13h 30m 41.3s , +38d 04' 30.2" }
         +/- 1.30189387289411 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.450587711528834 [arcmin] (formal 1-sigma fit error)
    SNR: 20.8659890712778
 
  Angular difference between the analysis and refined position is 0.945718 arcmin
 
  Partial Coding Fraction: 0.9375    [ including projection effects ]

  Duration
     T90: 10.9199999570847 +/- 3.56827627531245
        Measured from: 0.143999934196472
                   to: 11.0639998912811     [s; relative to TRIGTIME]
     T50: 4.58399999141693 +/- 0.765704856535722
        Measured from: 1.3639999628067
                   to: 5.94799995422363     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.395999908447266     
                   to: 1.39599990844727     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.472000002861023     
                   to: 14.5719999074936     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.363007   0.390978   0.145252   0.056190
           0.025555   0.026777   0.023874   0.023386 [error]
 Peak      0.064971   0.067311   0.036441   0.010801
           0.007326   0.007608   0.006628   0.006062 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   15.044   -0.472   14.572
T90    10.920    0.144   11.064
T50     4.584    1.364    5.948
Peak    1.000    0.396    1.396
 
 
====== 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      -2.105    -0.180      0.171       -           -               -         3.34e-03     -3.98e-04          3.91e-04      37.510   57
CPL     -1.490    -0.624      0.960       32.334     -28.127        17.538      7.81e-03     -4.87e-03          2.21e-02      35.630   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      -1.899     -0.241     0.227       -           -               -         1.00e-02     -1.60e-03          1.56e-03      48.720   57
CPL     -1.378     -0.800     1.159       48.757      N/A           N/A         2.02e-02        N/A               N/A         47.810   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   1.14e-07  1.45e-07  1.35e-07  2.20e-07  4.67e-07  6.13e-07   erg/cm2
      90%_error_low -1.34e-08 -1.27e-08 -2.18e-08 -6.31e-08 -4.91e-08 -9.00e-08   erg/cm2
      90%_error_hi   1.37e-08  1.26e-08  2.25e-08  7.89e-08  5.04e-08  1.02e-07   erg/cm2
Peak flux       PL   6.04e-01  4.81e-01  2.58e-01  2.02e-01  1.43e+00  1.54e+00   ph/cm2/s
      90%_error_low -1.06e-01 -6.00e-02 -5.35e-02 -7.03e-02 -1.78e-01 -1.97e-01   ph/cm2/s
      90%_error_hi   1.09e-01  5.99e-02  5.46e-02  9.09e-02  1.78e-01  1.98e-01   ph/cm2/s
 
Fluence        CPL   1.09e-07  1.55e-07  1.26e-07  7.09e-08  4.33e-07  4.60e-07   erg/cm2
      90%_error_low -1.51e-08 -2.43e-08 -2.94e-08 -5.27e-08 -5.95e-08 -8.26e-08   erg/cm2
      90%_error_hi   1.50e-08  1.82e-08  2.65e-08  2.14e-07  6.50e-08  1.17e-07   erg/cm2
Peak flux      CPL   5.79e-01  5.12e-01  2.53e-01  9.44e-02  1.41e+00  1.44e+00   ph/cm2/s
      90%_error_low -1.18e-01 -1.08e-01 -6.37e-02 -9.44e-02 -1.84e-01 -2.05e-01   ph/cm2/s
      90%_error_hi   1.18e-01  8.48e-02  5.91e-02  1.32e-01  1.84e-01  2.52e-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
  202.6722    38.0750   0.0092    19.3904   -34.6173         0.9661128     20.866 TRIG_00811561                 
 
Foreground time interval of the image:
 -0.472  11.045 (delta_t =  11.517 [sec])
Background time interval of the image:
-239.256  -0.472 (delta_t = 238.784 [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   -0.472 sec. to   14.572 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.10499     ( -0.17978   0.170695 )
Norm@50keV  : 3.34061E-03    ( -0.000397766   0.000390573 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          37.51 using 59 PHA bins.
# Reduced chi-squared =         0.6581 for     57 degrees of freedom 
# Null hypothesis probability =   9.784932e-01
 
Photon flux (15-150 keV)    in 15.04 sec: 0.526909 ( -0.044795  0.0448 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.6713e-07 ( -4.91289e-08  5.04381e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from   -0.472 sec. to   14.572 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.48981     ( -0.623981   0.959629 )
Epeak [keV] : 32.3344      ( -28.1276 17.5372 )
Norm@50keV  : 7.80513E-03    ( -0.004868   0.0221186 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          35.63 using 59 PHA bins.
# Reduced chi-squared =         0.6363 for     56 degrees of freedom 
# Null hypothesis probability =   9.845923e-01
 
Photon flux (15-150 keV)    in 15.04 sec: 0.512171 ( -0.048139  0.048232 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.32541e-07 ( -5.95164e-08  6.49641e-08 ) ergs/cm2

1-s peak spectrum fit

Power-law model

Time interval is from    0.396 sec. to    1.396 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.89884     ( -0.241389   0.227452 )
Norm@50keV  : 9.99795E-03    ( -0.00159957   0.00155718 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          48.72 using 59 PHA bins.
# Reduced chi-squared =         0.8548 for     57 degrees of freedom 
# Null hypothesis probability =   7.742589e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.43420 ( -0.17831  0.1783 ) ph/cm2/s
Energy fluence (15-150 keV)             : 9.19327e-08 ( -1.41684e-08  1.4587e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from    0.396 sec. to    1.396 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.37834     ( -0.800107   1.15884 )
Epeak [keV] : 48.7573      (   )
Norm@50keV  : 2.02420E-02    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          47.81 using 59 PHA bins.
# Reduced chi-squared =         0.8538 for     56 degrees of freedom 
# Null hypothesis probability =   7.736899e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.40688 ( -0.18414  0.18444 ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 10.92 sec.
Hardness ratio (energy fluence ratio) = 0.929843717821

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

S(15-50 keV)  = 2.582971e-07
S(50-150 keV) = 2.0883093e-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 = 2.896559014788390E-01, IMY = 1.999493210829509E-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:
-239.256000 -0.472000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
194.9327  33.4589    3.4  14.1  -14.5   0.7365   3.4 ------	UNKNOWN

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

Time interval of the image:
-0.472000 11.044600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
189.9599  -6.8495    2.3  45.2   49.6   0.9673   5.1 ------	UNKNOWN                       
229.8938   4.1730    2.1  57.5   -2.0   1.4967   5.6 ------	UNKNOWN                       
202.6722  38.0750    0.6  19.4  -34.6   0.9661  20.9 ------	UNKNOWN                       
104.2023  48.7745    2.4  53.3 -166.0   0.6704   4.7 ------	UNKNOWN

Post-slew image of 15-350 keV band

Time interval of the image:
63.644600 962.807700
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.4493  35.3753    6.3  41.1  -78.6   5.8218   1.8    2.0	Her X-1                       
174.5791  11.4671    3.1  36.5   74.9   5.3515   3.8 ------	UNKNOWN                       
168.8708  29.7963    2.8  29.0  107.8   3.7716   4.2 ------	UNKNOWN                       
232.8636  75.8129    3.2  40.1 -144.8   3.8671   3.6 ------	UNKNOWN                       
244.5979   0.2250    3.9  54.0  -31.6   8.2406   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