GRB200425A: 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 v2.47
    Process Start Time: Mon May 18 14:16:08 EDT 2020
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger967774
======================================================================

  Trigger: 00967774      Segment: 000

  BAT Trigger Time: 609466606.592   [s; MET]
      Trigger Stop: 609466610.688   [s; MET]
               UTC: 2020-04-25T00:16:21.762420    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 85.2407720384269   Dec: -13.4588771838186  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    8.62
     Image Trigger?:     NO
     Rate S/N Ratio:     13.490737563232  [ if not an image trigger ]
     Image S/N Ratio:    8.62

  Analysis Position:   [ source = BAT ]
    RA: 85.2407720384269   Dec: -13.4588771838186  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 85.2173769200413   Dec: -13.3994730425819  [deg; J2000]  
        { 05h 40m 52.2s , -13d 23' 58.1" }
         +/- 1.95064636822535 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.987794856144153 [arcmin] (formal 1-sigma fit error)
    SNR: 11.7105583823982
 
  Angular difference between the analysis and refined position is 3.816803 arcmin
 
  Partial Coding Fraction: 1.015625    [ including projection effects ]

  Duration
     T90: 81 +/- 21.6621790224345
        Measured from: -41.5920000076294
                   to: 39.4079999923706     [s; relative to TRIGTIME]
     T50: 28 +/- 10.1980390271856
        Measured from: -23.5920000076294
                   to: 4.40799999237061     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 2.40799999237061     
                   to: 3.40799999237061     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -47.5920000076294     
                   to: 58.4079999923706     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.526994   0.624328   0.581243   0.131340
           0.069188   0.072306   0.063782   0.058385 [error]
 Peak      0.020831   0.035056   0.025643   0.005298
           0.007064   0.007723   0.006551   0.005949 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  106.000  -47.592   58.408
T90    81.000  -41.592   39.408
T50    28.000  -23.592    4.408
Peak    1.000    2.408    3.408
 
 
====== 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      -1.301    -0.210      0.213       -           -               -         1.17e-03     -1.29e-04          1.28e-04      77.600   57
CPL     -1.313    -0.197      0.230     9999.360    -9999.360      -9999.360      1.16e-03     -1.22e-04          1.36e-04      77.650   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      -1.243     -0.384     0.396       -           -               -         5.93e-03     -1.38e-03          1.38e-03      46.050   57
CPL      0.105     -1.515     2.019       78.638     -25.939       -78.638      2.77e-02     -2.77e-02          7.98e-01      44.500   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   1.31e-07  2.72e-07  4.41e-07  1.61e-06  1.22e-06  2.45e-06   erg/cm2
      90%_error_low -2.70e-08 -3.34e-08 -6.39e-08 -4.70e-07 -1.55e-07 -5.19e-07   erg/cm2
      90%_error_hi   2.84e-08  3.27e-08  6.29e-08  6.00e-07  1.57e-07  6.30e-07   erg/cm2
Peak flux       PL   1.91e-01  2.24e-01  1.89e-01  2.71e-01  7.01e-01  8.75e-01   ph/cm2/s
      90%_error_low -7.43e-02 -5.90e-02 -5.21e-02 -1.26e-01 -1.65e-01 -2.12e-01   ph/cm2/s
      90%_error_hi   8.32e-02  5.77e-02  5.15e-02  1.83e-01  1.65e-01  2.20e-01   ph/cm2/s
 
Fluence        CPL   1.31e-07  2.72e-07  4.41e-07  1.85e-06  1.23e-06  2.41e-06   erg/cm2
      90%_error_low -2.71e-08 -3.34e-08    N/A       N/A    -1.64e-07 -6.32e-07   erg/cm2
      90%_error_hi   2.83e-08  3.26e-08    N/A       N/A     1.47e-07  6.23e-07   erg/cm2
Peak flux      CPL   1.48e-01  2.50e-01  2.07e-01  7.90e-02  6.62e-01  6.84e-01   ph/cm2/s
      90%_error_low -9.44e-02 -7.12e-02 -6.12e-02 -7.90e-02 -1.79e-01 -1.98e-01   ph/cm2/s
      90%_error_hi   1.01e-01  7.71e-02  6.35e-02  2.39e-01  1.75e-01  3.07e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
   85.2174   -13.3995   0.0165    12.7357    -4.6855         1.6747031     11.711 TRIG_00967774                 
 
Foreground time interval of the image:
-47.592  41.509 (delta_t =  89.101 [sec])
Background time interval of the image:
-239.592 -47.592 (delta_t = 192.000 [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  -47.592 sec. to   58.408 sec.
XSPEC12>exit
 XSPEC: quit
 
 
Photon index: -1.30127     ( -0.210257   0.212919 )
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.30127     ( -0.212919   0.210257 )
Norm@50keV  : 1.16557E-03    ( -0.00012879   0.000128443 )
------------------------------------------------------------
 
Photon flux (15-150 keV)    in 106 sec: 0.139090 ( -0.015557  0.015591 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.22066e-06 ( -1.54741e-07  1.56564e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from  -47.592 sec. to   58.408 sec.
 XSPEC: quit
 
 
Photon index: -1.29838     ( -0.198501   0.228851 )
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.29838     ( -0.228851   0.198501 )
Epeak [keV] : 1.00000E+04      ( -10000 -10000 )
Norm@50keV  : 1.17029E-03    ( -0.000129566   0.000127976 )
------------------------------------------------------------
 
Photon flux (15-150 keV)    in 106 sec: 0.139069 ( -0.015555  0.01558 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.22972e-06 ( -1.64431e-07  1.46751e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    2.408 sec. to    3.408 sec.
XSPEC12>exit
 XSPEC: quit
 
 
Photon index: -1.24304     ( -0.384041   0.396401 )
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.24304     ( -0.396401   0.384041 )
Norm@50keV  : 5.93265E-03    ( -0.0013803   0.0013785 )
------------------------------------------------------------
 
Photon flux (15-150 keV)    in 1 sec: 0.700893 ( -0.164948  0.165423 ) ph/cm2/s
Energy fluence (15-150 keV)             : 5.94895e-08 ( -1.52918e-08  1.56209e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    2.408 sec. to    3.408 sec.
 XSPEC: quit
 
 
Photon index: 0.104781     ( -1.51493   2.01906 )
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.104781     ( -2.01906   1.51493 )
Epeak [keV] : 78.6378      ( -25.9373 -78.6362 )
Norm@50keV  : 2.77494E-02    ( -0.0277518   0.798008 )
------------------------------------------------------------
 
Photon flux (15-150 keV)    in 1 sec: 0.662496 ( -0.179121  0.175135 ) ph/cm2/s
Energy fluence (15-150 keV)             : 5.34663e-08 ( -1.62323e-08  1.76747e-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 = 2.252587250891085E-01, IMY = 1.846227611429985E-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:
-239.592000 -47.592000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6453  22.0169    0.8  47.5  -21.0   7.7340  13.8    0.7	Crab                          
 37.1865 -75.8316    2.8  54.8  167.3   5.5299   4.5 ------	UNKNOWN                       
 36.8019 -75.5928    3.3  54.7  167.6   5.4765   4.7 ------	UNKNOWN                       
 82.9026 -37.0546    2.5  11.8  147.1   1.0661   4.7 ------	UNKNOWN                       

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

Time interval of the image:
-47.592000 41.508600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6601  21.8542    4.4  47.4  -21.0  -0.7848  -2.6    9.7	Crab                          
 85.2174 -13.3995    1.0  12.7   -4.7   1.6746  11.7 ------	UNKNOWN                       
 63.1650  -9.5315    2.0  23.1  -74.2   1.1038   5.7 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
74.908590 836.008600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6595  22.0283    0.4  35.5  -27.5  31.5149  27.0    1.7	Crab                          
 60.0373 -65.5238    2.8  54.8  167.5  17.8436   4.1 ------	UNKNOWN                       
101.1035  -7.4516    3.0  16.7   45.5   3.3315   3.8 ------	UNKNOWN                       
 72.3363  27.1959    3.0  42.5  -42.1   5.4644   3.8 ------	UNKNOWN                       
 86.2690  43.4097    2.2  56.9  -24.1  18.8715   5.2 ------	UNKNOWN                       
 32.3706 -24.2060    3.3  50.9 -135.4  15.5089   3.5 ------	UNKNOWN