GRB180930A: 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 26 19:23:28 EDT 2018
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger864584
======================================================================

  Trigger: 00864584      Segment: 000

  BAT Trigger Time: 560004250.944   [s; MET]
      Trigger Stop: 560004251.968   [s; MET]
               UTC: 2018-09-30T12:43:49.266800    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 76.8702927582825   Dec: -25.1383099129713  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.59
     Image Trigger?:     NO
     Rate S/N Ratio:     11.1803398874989  [ if not an image trigger ]
     Image S/N Ratio:    7.59

  Analysis Position:   [ source = BAT ]
    RA: 76.8702927582825   Dec: -25.1383099129713  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 76.8940422075677   Dec: -25.1244390815755  [deg; J2000]  
        { 05h 07m 34.6s , -25d 07' 28.0" }
         +/- 2.25147425055248 [arcmin] (estimated 90% radius based on SNR)
         +/- 1.02088927401161 [arcmin] (formal 1-sigma fit error)
    SNR: 9.54100484783182
 
  Angular difference between the analysis and refined position is 1.535230 arcmin
 
  Partial Coding Fraction: 0.875    [ including projection effects ]

  Duration
     T90: 6.80400002002716 +/- 0.955790754386789
        Measured from: -2.98000001907349
                   to: 3.82400000095367     [s; relative to TRIGTIME]
     T50: 2.71599996089935 +/- 1.95360585053105
        Measured from: -0.672000050544739
                   to: 2.04399991035461     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.139999985694885     
                   to: 1.13999998569489     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -3.24399995803833     
                   to: 4.2039999961853     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.129486   0.156480   0.058242   0.029797
           0.018584   0.019473   0.017086   0.015373 [error]
 Peak      0.037578   0.043976   0.008842   0.001839
           0.007125   0.007323   0.006472   0.005738 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    7.448   -3.244    4.204
T90     6.804   -2.980    3.824
T50     2.716   -0.672    2.044
Peak    1.000    0.140    1.140
 
 
====== 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      -1.873    -0.290      0.271       -           -               -         2.96e-03     -5.60e-04          5.41e-04      53.950   57
CPL     -1.731    -0.554      1.533       77.776     -77.757       -77.776      3.59e-03        N/A               N/A         53.900   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      -2.178     -0.448     0.387       -           -               -         5.27e-03     -1.64e-03          1.58e-03      57.260   57
CPL     -1.990      1.990     1.990        1.795      N/A           N/A         7.03e-03        N/A               N/A         57.160   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   4.00e-08  5.86e-08  6.39e-08  1.31e-07  2.03e-07  2.93e-07   erg/cm2
      90%_error_low -8.31e-09 -8.77e-09 -1.61e-08 -5.56e-08 -3.71e-08 -7.54e-08   erg/cm2
      90%_error_hi   8.54e-09  8.74e-09  1.65e-08  7.79e-08  3.83e-08  9.32e-08   erg/cm2
Peak flux       PL   4.18e-01  2.83e-01  1.25e-01  7.63e-02  8.63e-01  9.02e-01   ph/cm2/s
      90%_error_low -1.07e-01 -6.09e-02 -4.82e-02 -4.38e-02 -1.74e-01 -1.86e-01   ph/cm2/s
      90%_error_hi   1.10e-01  5.97e-02  5.20e-02  7.07e-02  1.74e-01  1.88e-01   ph/cm2/s
 
Fluence        CPL   3.96e-08  5.97e-08  6.35e-08  9.73e-08  1.99e-07  2.60e-07   erg/cm2
      90%_error_low -8.96e-09 -9.70e-09 -2.01e-08    N/A    -4.73e-08 -1.06e-07   erg/cm2
      90%_error_hi   8.85e-09  1.34e-08  1.70e-08    N/A     4.07e-08  5.92e-08   erg/cm2
Peak flux      CPL   4.17e-01  2.85e-01  1.27e-01  7.21e-02  8.63e-01  9.00e-01   ph/cm2/s
      90%_error_low -1.33e-01 -1.52e-01 -4.99e-02     N/A   -1.73e-01 -1.80e-01   ph/cm2/s
      90%_error_hi   1.13e-01  5.77e-02  5.05e-02     N/A    1.74e-01  2.01e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
   76.8940   -25.1244   0.0201    26.8144  -167.5695         0.3763572      9.541 TRIG_00864584                 
 
Foreground time interval of the image:
 -3.244   4.204 (delta_t =   7.448 [sec])
Background time interval of the image:
-105.243  -3.244 (delta_t = 101.999 [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   -3.244 sec. to    4.204 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.87319     ( -0.289999   0.270707 )
Norm@50keV  : 2.95798E-03    ( -0.000560058   0.000541102 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          53.95 using 59 PHA bins.
# Reduced chi-squared =         0.9464 for     57 degrees of freedom 
# Null hypothesis probability =   5.903835e-01
 
Photon flux (15-150 keV)    in 7.448 sec: 0.419776 ( -0.062349  0.062352 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.02563e-07 ( -3.71e-08  3.8267e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -3.244 sec. to    4.204 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.73113     ( -0.553564   1.53323 )
Epeak [keV] : 77.7763      ( -78.0184 -78.0379 )
Norm@50keV  : 3.58886E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          53.90 using 59 PHA bins.
# Reduced chi-squared =         0.9625 for     56 degrees of freedom 
# Null hypothesis probability =   5.547012e-01
 
Photon flux (15-150 keV)    in 7.448 sec: 0.417716 ( -0.064827  0.063516 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.98916e-07 ( -4.73437e-08  4.07187e-08 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    0.140 sec. to    1.140 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.17818     ( -0.448305   0.387264 )
Norm@50keV  : 5.27434E-03    ( -0.00163537   0.00157845 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          57.26 using 59 PHA bins.
# Reduced chi-squared =          1.005 for     57 degrees of freedom 
# Null hypothesis probability =   4.654886e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.863375 ( -0.17399  0.174065 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.94527e-08 ( -1.27769e-08  1.35879e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    0.140 sec. to    1.140 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.74607     ( 1.99005   1.99005 )
Epeak [keV] : 21.6495      (   )
Norm@50keV  : 9.93478E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          57.10 using 59 PHA bins.
# Reduced chi-squared =          1.020 for     56 degrees of freedom 
# Null hypothesis probability =   4.339410e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.863075 ( -0.17302  0.174455 ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 6.804 sec.
Hardness ratio (energy fluence ratio) = 1.09191795838

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

S(15-50 keV)  = 9.853682e-08
S(50-150 keV) = 1.0402989e-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 = -4.936019236281153E-01, IMY = 1.088010896182246E-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:
-105.243400 -3.244000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 43.4307 -12.8661    2.3  32.9  121.9   1.2561   5.1 ------	UNKNOWN                       
 34.1637 -24.0573    2.4  26.1   96.2   0.9541   4.8 ------	UNKNOWN                       

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

Time interval of the image:
-3.244000 4.204000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 40.0529  -5.0227    2.1  41.3  119.8   0.7149   5.4 ------	UNKNOWN                       
 76.8941 -25.1244    1.2  26.8 -167.6   0.3764   9.5 ------	UNKNOWN                       
303.7906 -63.3568    2.1  58.9   -9.5   1.0430   5.4 ------	UNKNOWN                       
 87.5674 -56.9285    1.9  24.3  -86.1   0.2637   6.1 ------	UNKNOWN                       
277.5768 -72.7488    2.2  58.9  -25.1   1.1275   5.2 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
192.156600 719.520700
720.056000 962.160000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6425  22.0140    0.5  47.6  177.3  30.8554  21.4    0.5	Crab                          
 45.5532  -6.8946    3.3  35.0  104.8   5.0138   3.5 ------	UNKNOWN                       
 47.3305 -20.3085    2.1  27.6   82.8   5.4043   5.5 ------	UNKNOWN                       
 66.7992   2.9819    2.6  29.8  148.2   3.6851   4.4 ------	UNKNOWN                       
107.0314  21.3979    2.7  55.0 -156.4  11.3774   4.3 ------	UNKNOWN                       
121.9494 -24.2451    3.2  40.8  -92.6  10.8480   3.6 ------	UNKNOWN