GRB190427A: 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: Mon May 20 17:12:33 EDT 2019
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger900730
======================================================================

  Trigger: 00900730      Segment: 000

  BAT Trigger Time: 578032477.88   [s; MET]
      Trigger Stop: 578032477.912   [s; MET]
               UTC: 2019-04-27T04:34:15.072360    [includes UTCF correction] 
       Where From?: (*SHORT BURST*) TDRSS scaled map message

  BAT 
    RA: 280.212789126915   Dec: 40.3223823960134  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    11.1
     Image Trigger?:     NO
     Rate S/N Ratio:     54.5435605731786  [ if not an image trigger ]
     Image S/N Ratio:    11.1

  Analysis Position:   [ source = BAT ]
    RA: 280.212789126915   Dec: 40.3223823960134  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 280.21938424872   Dec: 40.3099655134466  [deg; J2000]  
        { 18h 40m 52.7s , +40d 18' 35.9" }
         +/- 2.42691235850928 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.98772115319082 [arcmin] (formal 1-sigma fit error)
    SNR: 8.5711896371427
 
  Angular difference between the analysis and refined position is 0.803791 arcmin
 
  Partial Coding Fraction: 0.6875    [ including projection effects ]

  Duration
     T90: 0.191999912261963 +/- 0.202385803424389
        Measured from: -0.00800001621246338
                   to: 0.1839998960495     [s; relative to TRIGTIME]
     T50: 0.0639998912811279 +/- 0.0640000104904175
        Measured from: -0.00800001621246338
                   to: 0.0559998750686646     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.315999984741211     
                   to: 0.684000015258789     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.00800001621246338     
                   to: 0.312000036239624     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.032781   0.074258   0.056610   0.023577
           0.006652   0.007873   0.007595   0.005706 [error]
 Peak      0.044859   0.072767   0.061272   0.016136
           0.010091   0.010823   0.009891   0.007976 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    0.320   -0.008    0.312
T90     0.192   -0.008    0.184
T50     0.064   -0.008    0.056
Peak    1.000   -0.316    0.684
 
 
====== 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      -1.250    -0.212      0.213       -           -               -         3.79e-02     -4.77e-03          4.76e-03      55.660   57
CPL     -1.049    -0.394      0.957      240.147    -240.147      -240.147      4.80e-02     -4.80e-02          9.68e-02      55.480   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      -1.290     -0.292     0.297       -           -               -         1.34e-02     -2.10e-03          2.09e-03      48.850   57
CPL     -1.299     -0.283     0.491     9999.360    -9999.360      -9999.360      1.34e-02     -2.05e-03          1.41e-02      48.870   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   1.23e-08  2.63e-08  4.42e-08  1.70e-07  1.21e-07  2.53e-07   erg/cm2
      90%_error_low -2.60e-09 -3.54e-09 -7.00e-09 -5.15e-08 -1.74e-08 -5.75e-08   erg/cm2
      90%_error_hi   2.74e-09  3.50e-09  6.92e-09  6.48e-08  1.76e-08  6.89e-08   erg/cm2
Peak flux       PL   4.52e-01  5.16e-01  4.22e-01  5.77e-01  1.60e+00  1.97e+00   ph/cm2/s
      90%_error_low -1.30e-01 -9.28e-02 -8.26e-02 -2.11e-01 -2.53e-01 -3.21e-01   ph/cm2/s
      90%_error_hi   1.41e-01  9.01e-02  8.06e-02  2.81e-01  2.54e-01  3.30e-01   ph/cm2/s
 
Fluence        CPL   1.19e-08  2.69e-08  4.49e-08  1.23e-07  1.20e-07  2.07e-07   erg/cm2
      90%_error_low -3.02e-09 -4.03e-09 -7.44e-09 -8.74e-08 -1.95e-08 -8.89e-08   erg/cm2
      90%_error_hi   2.52e-09  4.55e-09  7.74e-09  8.99e-08  1.83e-08  1.09e-07   erg/cm2
Peak flux      CPL   4.52e-01  5.15e-01  4.19e-01  6.43e-01  1.60e+00  1.98e+00   ph/cm2/s
      90%_error_low     N/A       N/A       N/A       N/A   -2.53e-01 -4.19e-01   ph/cm2/s
      90%_error_hi      N/A       N/A       N/A       N/A    2.54e-01  2.85e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  280.2194    40.3100   0.0224    24.5663   148.5102         0.0672358      8.571 TRIG_00900730                 
 
Foreground time interval of the image:
 -0.008   0.021 (delta_t =   0.029 [sec])
Background time interval of the image:
-91.579  -0.008 (delta_t =  91.571 [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   -0.008 sec. to    0.312 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.25021     ( -0.212448   0.213026 )
Norm@50keV  : 3.79243E-02    ( -0.00476747   0.00475549 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          55.66 using 59 PHA bins.
# Reduced chi-squared =         0.9764 for     57 degrees of freedom 
# Null hypothesis probability =   5.255674e-01
 
Photon flux (15-150 keV)    in 0.32 sec: 4.48561 ( -0.56266  0.56295 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.21462e-07 ( -1.73883e-08  1.75847e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.008 sec. to    0.312 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.04912     ( -0.393681   0.956696 )
Epeak [keV] : 240.147      ( -240.266 -240.266 )
Norm@50keV  : 4.79588E-02    ( -0.0479518   0.0968152 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          55.48 using 59 PHA bins.
# Reduced chi-squared =         0.9907 for     56 degrees of freedom 
# Null hypothesis probability =   4.944291e-01
 
Photon flux (15-150 keV)    in 0.32 sec: 4.45732 ( -0.57601  0.57403 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.19627e-07 ( -1.95235e-08  1.82714e-08 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   -0.316 sec. to    0.684 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.29047     ( -0.292141   0.296961 )
Norm@50keV  : 1.34318E-02    ( -0.00209979   0.00209324 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          48.85 using 59 PHA bins.
# Reduced chi-squared =         0.8570 for     57 degrees of freedom 
# Null hypothesis probability =   7.703566e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.59969 ( -0.25302  0.25382 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.33058e-07 ( -2.3675e-08  2.40289e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.316 sec. to    0.684 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.2986     ( -0.283461   0.490238 )
Epeak [keV] : 9999.36      ( -9999.36 -9999.36 )
Norm@50keV  : 1.34210E-02    ( -0.00210326   0.0140707 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          48.87 using 59 PHA bins.
# Reduced chi-squared =         0.8726 for     56 degrees of freedom 
# Null hypothesis probability =   7.393461e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.59944 ( -0.25333  0.25366 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.34029e-07 ( -3.21276e-08  3.07569e-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 = -3.898055216540743E-01, IMY = -2.387781188044245E-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:
-91.579400 -0.008000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.3358  35.2215    3.1  41.7  125.4  -3.2393  -3.7    9.4	Her X-1                       
268.3336  -1.3320   12.2  39.0   63.7   0.6373   0.9    7.5	SW J1753.5-0127               
274.1860 -14.1686    5.4  44.5   44.2   1.2627   2.1   13.1	GX 17+2                       
284.8985 -24.8859    4.7  49.5   25.2   1.6084   2.5    7.8	HT1900.1-2455                 
288.7973  10.9329   76.1  15.7   52.1   0.0323   0.2    0.8	GRS 1915+105                  
299.5905  35.2252    1.7  12.9 -174.7   1.4121   6.9    1.4	Cyg X-1                       
308.0695  41.1004    5.4  19.9 -155.0  -0.4267  -2.1    9.1	Cyg X-3                       
326.2297  38.2843    9.2  27.5 -124.4   0.3204   1.3    3.5	Cyg X-2                       
281.0810 -22.0418    2.5  48.1   30.9   2.5761   4.7 ------	UNKNOWN                       
273.1575  35.9207    2.9  27.0  133.2   1.1277   4.0 ------	UNKNOWN                       
293.4654  23.4504    2.4   6.2  108.5   0.8952   4.7 ------	UNKNOWN                       

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

Time interval of the image:
-0.008000 0.020600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.4517  35.3549   16.1  41.6  125.6   0.0197   0.7    0.8	Her X-1                       
268.2600  -1.5844    5.4  39.2   63.5   0.0486   2.1   10.2	SW J1753.5-0127               
273.9688 -14.0043    6.6  44.4   44.5   0.0365   1.7    2.9	GX 17+2                       
284.8943 -24.8736    4.6  49.5   25.2   0.0581   2.5    8.2	HT1900.1-2455                 
288.6789  10.7782    0.0  15.9   52.1   0.0018   0.3   12.3	GRS 1915+105                  
299.7663  35.2305    6.7  12.9 -174.1  -0.0099  -1.7    8.8	Cyg X-1                       
308.2717  41.1022   27.0  20.0 -154.6  -0.0025  -0.4   11.6	Cyg X-3                       
325.9862  38.2056   10.1  27.3 -124.4  -0.0072  -1.1   11.2	Cyg X-2                       
280.2194  40.3099    1.3  24.6  148.5   0.0672   8.6 ------	UNKNOWN                       
304.6451 -28.2694    2.3  50.8    1.8   0.0670   5.0 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
91.020600 502.820590
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
326.0680  38.3064    5.2  58.3 -176.2  -7.7220  -2.2    5.0	Cyg X-2                       
303.2507  -8.1560    2.9  40.3  118.2  10.1058   3.9 ------	UNKNOWN                       
351.3675  32.1846    2.0  50.3 -151.5   8.9890   5.7 ------	UNKNOWN