Analysis for Ground-detected GRB170524B

Analysis Summary

Notes:

==========================================================================
           BAT GROUND-DETECTED GRB DATA PROCESSING REPORT                 
            (This burst occurred during telescope slew)                  
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Thu May 25 09:50:58 EDT 2017
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/GRB170524B
======================================================================

  Trigger: 00753445      Segment: 006

  BAT Trigger Time: 517315259.2
               UTC: 2017-05-24T10:40:40.20   [includes UTCF correction]
       Where From?: Ground analysis (best_duration.txt)
  NOTE: BAT trigger time for ground-detected burst during slew is the T100 start time.
 
  Analysis Position:   [ source = GCN ]
    RA: 90.8641   Dec: -17.0864  [deg; J2000]
 
  Refined Position:   [ source = BAT mosaic image ]
    RA: 90.8655956209218   Dec: -17.080680000449  [deg; J2000]
        { 06h 03m 27.7s , -17d -4' -50.4" }
        +/- 0.664203320764 [arcmin] (estimated 90% radius based on SNR)
    SNR: 54.5796631666
 
  Angular difference between the GCN position (ra=90.8641, dec=-17.0864 deg) and this refined position is 0.354 arcmin
 
  Partial Coding Fraction: Unavailable because the burst occurred during slew.
 
  Duration
     T90: 46.4000000357628 +/- 1.6
        Measured from: 0
                   to: 46.4     [s; relative to TRIGTIME]
     T50: 27.2000000476837 +/- 1.6
        Measured from: 4.8
                   to: 32     [s; relative to TRIGTIME]
 
=== 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   Power-law 5.97e-07 1.36e-06 2.44e-06 1.04e-05 6.64e-06 1.48e-05   erg/cm2
              Error 4.16e-08 5.55e-08 8.31e-08 8.40e-07 2.16e-07 8.68e-07   erg/cm2
Peak flux Power-law 6.62e-04 6.89e-03 7.58e-02 8.02e+00 3.38e-01 7.95e+00   ph/cm2/s
              Error -------- -------- -------- -------- -------- --------   ph/cm2/s
 
Fluence   Cutoff-PL 3.47e-07 4.62e-07 4.74e-07 1.11e-06 1.58e-06 2.42e-06   erg/cm2
              Error 4.96e-08 7.43e-08 5.41e-08 -------- 2.07e-07 1.91e-07   erg/cm2
Peak flux Cutoff-PL 1.99e+00 2.53e+00 2.34e+00 3.79e+00 8.16e+00 1.08e+01   ph/cm2/s
              Error -------- -------- -------- -------- 3.74e-01 8.78e-01   ph/cm2/s
 
Fluence        Band -------- -------- -------- -------- -------- --------   erg/cm2
              Error -------- -------- -------- -------- -------- --------   erg/cm2
Peak flux      Band -------- -------- -------- -------- -------- --------   ph/cm2/s
              Error -------- -------- -------- -------- -------- --------   ph/cm2/s
 
=== Time-averaged spectral analysis ===
 
Model Ph_index Ph_90err Epeak  Epeak_90err Norm     Nomr_90err chi2   dof
PL    1.152    0.058    -      -           1.35e-02 4.37e-04   73.490 57
CPL   0.938    0.179     296.3  -86.1      1.67e-02 3.73e-03   70.910 56
 
The chi2 of BB fit is Chi-Squared which shows a significant improvement in the fit over a PL.
Check the BB fit.
 
=== 1-s peak spectral analysis ===
 
Model Ph_index Ph_90err Epeak  Epeak_90err Norm     Nomr_90err chi2   dof
PL    1.109    0.076    -      -           7.02e-02 2.86e-03   43.020 57
CPL   1.104    0.200    9998.8    0.0      7.05e-02 1.16e-02   43.030 56
 
Model      : spectral model: simple power-law (PL) and cutoff power-law (CPL)
Ph_index   : photon index: E^-{Ph_index} (minus sign is not included in the 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 PL model and at 1 keV in CPL model
Nomr_90err : 90% error of the normalization
chi2       : Chi-Squared
dof        : degree of freedom
 
=== Table of the duration information ==
 
        Value   tstart    tstop
T100   49.600    0.000   49.600
T90    46.400    0.000   46.400
T50    27.200    4.800   32.000
Peak    1.000    6.700    7.700

Image

Note1: The mosaic image is made with timebin = 0.2 s; energybin = 15-350 keV

Note2: The mosaic image uses Galactic coordinate.

#RAcent DECcent POSerr Theta  Phi  Peak_Cts  SNR Name
90.866 -17.081 0.001 38.131 25.491 0.183 54.580 UNKNOWN
 
Image time interval: 0.000 to 49.600 [sec]

Lightcurves

Notes:

Best duration plot

1 s binning

From T0-310 s to T0+310 s
From T100_start - 20 s to T100_end + 30 s
Full time interval

64 ms binning

Full time interval
From T100_start to T100_end
From T0-5 sec to T0+5 sec

16 ms binning

From T100_start-5 s to T100_start+5 s

8 ms binning

From T100_start-3 s to T100_start+3 s

2 ms binning

From T100_start-1 s to T100_start+1 s

SN=5 or 10 sec. binning (whichever binning is satisfied first)

SN=5 or 10 sec. binning (T < 200 sec)

Spectral Evolution

Spectra

Notes:

Time averaged spectrum fit using the pre-slew DRM

Power-law model
Time interval is from    1.800 sec. to   49.600 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.15249     ( -0.0583359   0.0578185 )
Norm@50keV  : 1.35223E-02    ( -0.000437508   0.000435985 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          73.49 using 59 PHA bins.
# Reduced chi-squared =          1.289 for     57 degrees of freedom 
# Null hypothesis probability =   6.975279e-02
 
Photon flux (15-150 keV)    in 47.8 sec: 1.57745 ( -0.05472  0.05488 ) ph/cm2/s
Energy fluence (15-150 keV)             : 6.64965e-06 ( -2.15548e-07  2.15941e-07 ) ergs/cm2
 
Cutoff power-law model
Time interval is from    1.800 sec. to   49.600 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.938330     ( -0.239752   0.117274 )
Epeak [keV] : 296.333      ( -124.223 -296.333 )
Norm@50keV  : 1.66664E-02    ( -0.00321034   0.00424021 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          70.91 using 59 PHA bins.
# Reduced chi-squared =          1.266 for     56 degrees of freedom 
# Null hypothesis probability =   8.654024e-02
 
Photon flux (15-150 keV)    in 47.8 sec: 1.55698 ( -0.05851  0.05871 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.58179e-06 ( -2.28819e-07  1.84363e-07 ) ergs/cm2
 
Band function
Time interval is from    1.800 sec. to   49.600 sec.
 
 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       :    (     )
beta        :     (     )
Epeak [keV] :       (   )
Norm@50keV   :     (     )
------------------------------------------------------------
 
Photon flux (15-150 keV)    in  sec:  (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2
 
Single BB
 
Spectral model blackbody:
------------------------------------------------------------
Parameters  : value    Lower 90%  Upper 90%
kT [keV]    : 21.6274  (  )
R^2/D10^2   : 5.61615E-02  (   )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared =         232.59 using 59 PHA bins.
# Reduced chi-squared =         4.0806 for     57 degrees of freedom 
# Null hypothesis probability =   4.497114e-23
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  2.342e-07   1.563e-08
25- 50  1.226e-06   6.620e-08
50-150  4.281e-06   2.008e-07
15-150  5.741e-06   2.055e-07
Thermal bremsstrahlung (OTTB)
 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 199.363       (      )
Norm        : 6.82958       (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =         222.04 using 59 PHA bins.
# Reduced chi-squared =         3.8954 for     57 degrees of freedom 
# Null hypothesis probability =   2.493312e-21
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  8.129e-07   2.772e-08
25- 50  1.564e-06   5.378e-08
50-150  3.430e-06   1.152e-07
15-150  5.806e-06   2.151e-07
Double BB
 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 9.07963        (-1.27583      1.40978)
R1^2/D10^2  : 0.535393        (-0.183349      0.321128)
kT2 [keV]   : 35.3878        (-4.39616      6.85866)
R2^2/D10^2  : 9.66926E-03    (-0.00416275   0.00542942)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          74.31 using 59 PHA bins.
# Reduced chi-squared =          1.351 for     55 degrees of freedom 
# Null hypothesis probability =   4.244704e-02
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  4.940e-07   6.317e-08
25- 50  1.423e-06   1.240e-07
50-150  4.695e-06   5.014e-07
15-150  6.612e-06   6.573e-07

Peak spectrum fit

Power-law model
Time interval is from    0.000 sec. to    0.000 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.10900     ( -0.0757386   0.0754133 )
Norm@50keV  : 7.01692E-02    ( -0.00286245   0.00286098 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          43.02 using 59 PHA bins.
# Reduced chi-squared =         0.7547 for     57 degrees of freedom 
# Null hypothesis probability =   9.148571e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.337830 (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.31627e-07 ( -3.3266e-08  3.33705e-08 ) ergs/cm2
 
Cutoff power-law model
Time interval is from    0.000 sec. to    0.000 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.10387     ( -0.216044   0.18327 )
Epeak [keV] : 9998.78      ( -9998.82 -9998.82 )
Norm@50keV  : 7.05431E-02    ( -0.00286768   0.0202584 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          43.03 using 59 PHA bins.
# Reduced chi-squared =         0.7684 for     56 degrees of freedom 
# Null hypothesis probability =   8.981669e-01
 
Photon flux (15-150 keV)    in 1 sec: 8.15836 ( -0.38661  0.36217 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.61128e-07 ( -2.48455e-08  1.92942e-08 ) ergs/cm2
 
Band function
Time interval is from    0.000 sec. to    0.000 sec.
 
 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       :    (     )
beta        :     (     )
Epeak [keV] :       (   )
Norm@50keV   :     (     )
------------------------------------------------------------
 
Photon flux (15-150 keV)    in  sec:  (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2
 
Single BB
 
Spectral model blackbody:
------------------------------------------------------------
Parameters  : value    Lower 90%  Upper 90%
kT [keV]    : 20.8249  (  )
R^2/D10^2   : 0.331891  (   )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared =         170.87 using 59 PHA bins.
# Reduced chi-squared =         2.9977 for     57 degrees of freedom 
# Null hypothesis probability =   2.646006e-13
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  2.729e-08   2.325e-09
25- 50  1.395e-07   8.350e-09
50-150  4.507e-07   3.095e-08
15-150  6.175e-07   3.405e-08
Thermal bremsstrahlung (OTTB)
 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 199.363       (      )
Norm        : 33.5326       (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =         141.82 using 59 PHA bins.
# Reduced chi-squared =         2.4881 for     57 degrees of freedom 
# Null hypothesis probability =   3.523716e-09
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  8.350e-08   3.735e-09
25- 50  1.606e-07   6.850e-09
50-150  3.523e-07   1.585e-08
15-150  5.964e-07   2.720e-08
Double BB
 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 8.02758        (-1.41126      1.54432)
R1^2/D10^2  : 4.16636        (-1.73793      3.77327)
kT2 [keV]   : 35.8795        (-5.24467      8.2569)
R2^2/D10^2  : 5.22228E-02    (-0.02414   0.0341133)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          46.78 using 59 PHA bins.
# Reduced chi-squared =         0.8505 for     55 degrees of freedom 
# Null hypothesis probability =   7.770901e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  5.804e-08   1.061e-08
25- 50  1.474e-07   1.945e-08
50-150  5.349e-07   8.315e-08
15-150  7.404e-07   9.695e-08
Webpage updated on:
Thu May 25 13:08:06 EDT 2017