GRB240727A: 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 v2.48
    Process Start Time: Sat Oct 19 15:07:00 EDT 2024
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1245074
======================================================================

  Trigger: 01245074      Segment: 000

  BAT Trigger Time: 743744808   [s; MET]
      Trigger Stop: 743744872   [s; MET]
               UTC: 2024-07-27T03:46:14.118700    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 236.448394680714   Dec: 8.59701811845367  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    9.65
     Image Trigger?:     YES
     Rate S/N Ratio:     0  [ if not an image trigger ]
     Image S/N Ratio:    9.65

  Analysis Position:   [ source = BAT ]
    RA: 236.448394680714   Dec: 8.59701811845367  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 236.450873339458   Dec: 8.61161363911493  [deg; J2000]  
        { 15h 45m 48.2s , +08d 36' 41.8" }
         +/- 1.60247541580108 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.714589779207759 [arcmin] (formal 1-sigma fit error)
    SNR: 15.5081242555699
 
  Angular difference between the analysis and refined position is 0.887991 arcmin
 
  Partial Coding Fraction: 1    [ including projection effects ]

  Duration
     T90: 177.883999943733 +/- 35.4630951235586
        Measured from: 2.62800002098083
                   to: 180.511999964714     [s; relative to TRIGTIME]
     T50: 71.5719999074936 +/- 23.736731013469
        Measured from: 28.1759999990463
                   to: 99.7479999065399     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 3.12000000476837     
                   to: 4.12000000476837     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -6.79200005531311     
                   to: 201.05999994278     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.714118   0.984099   0.668980   0.107781
           0.089933   0.086360   0.073421   0.063283 [error]
 Peak      0.028163   0.012784   0.013861   0.012521
           0.006418   0.005968   0.005113   0.004320 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  207.852   -6.792  201.060
T90   177.884    2.628  180.512
T50    71.572   28.176   99.748
Peak    1.000    3.120    4.120
 
 
====== 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      -1.621    -0.179      0.175       -           -               -         7.29e-04     -7.94e-05          7.86e-05      65.990   57
CPL     -0.913    -0.708      0.847       71.703     -18.821       747.707      1.73e-03     -9.88e-04          3.08e-03      63.070   56
 
 
=== 1-s peak 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      -1.900     -0.858     0.761       -           -               -         3.05e-03     -1.44e-03          1.22e-03      62.470   57
CPL     -1.907     -1.989     0.210     9999.340      N/A           N/A         3.04e-03        N/A               N/A         62.470   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   2.17e-07  3.70e-07  4.81e-07  1.26e-06  1.41e-06  2.33e-06   erg/cm2
      90%_error_low -3.43e-08 -3.80e-08 -6.93e-08 -3.41e-07 -1.64e-07 -4.10e-07   erg/cm2
      90%_error_hi   3.56e-08  3.79e-08  6.95e-08  4.18e-07  1.67e-07  4.71e-07   erg/cm2
Peak flux       PL   1.84e-01  1.47e-01  7.85e-02  6.12e-02  4.37e-01  4.71e-01   ph/cm2/s
      90%_error_low -9.48e-02 -4.56e-02 -7.85e-02 -6.12e-02 -1.36e-01 -1.50e-01   ph/cm2/s
      90%_error_hi   9.77e-02  4.56e-02  4.73e-02  1.18e-01  1.36e-01  1.53e-01   ph/cm2/s
 
Fluence        CPL   1.97e-07  4.00e-07  4.89e-07  4.51e-07  1.33e-06  1.54e-06   erg/cm2
      90%_error_low -4.02e-08 -4.82e-08 -7.72e-08 -2.75e-07 -1.82e-07 -3.33e-07   erg/cm2
      90%_error_hi   4.08e-08  5.01e-08  7.67e-08  8.09e-07  1.87e-07  8.11e-07   erg/cm2
Peak flux      CPL   1.72e-01  6.57e-02  2.74e-02  5.40e-03  2.87e-01  2.97e-01   ph/cm2/s
      90%_error_low -9.52e-02 -6.57e-02 -2.74e-02 -5.40e-03 -1.63e-01 -1.97e-01   ph/cm2/s
      90%_error_hi   9.54e-02  9.55e-02  3.26e-02  6.27e-02  2.21e-01  2.32e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  236.4509     8.6116   0.0125     4.8206   107.5921         1.7693882     15.508 TRIG_01245074                 
 
Foreground time interval of the image:
 -6.792  73.101 (delta_t =  79.893 [sec])
Background time interval of the image:
-239.000  -6.792 (delta_t = 232.208 [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   -6.792 sec. to  201.060 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.62143     ( -0.179056   0.175465 )
Norm@50keV  : 7.28798E-04    ( -7.94091e-05   7.85542e-05 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   65.99     using 59 bins.
 Reduced chi-squared = 1.15772
# Null hypothesis probability of 1.94e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 207.9 sec: 9.42898E-02 ( -0.0096179  0.0096272 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.41366e-06 ( -1.6422e-07  1.66515e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -6.792 sec. to  201.060 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.913108     ( -0.708018   0.847449 )
Epeak [keV] : 71.7034      ( -18.8214 747.706 )
Norm@50keV  : 1.73372E-03    ( -0.00098811   0.0030846 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   63.07     using 59 bins.
 Reduced chi-squared = 1.12625
# Null hypothesis probability of 2.41e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 207.9 sec: 9.13559E-02 ( -0.0100605  0.0100571 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.32542e-06 ( -1.81795e-07  1.87074e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    3.120 sec. to    4.120 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.8998     ( -0.857674   0.762013 )
Norm@50keV  : 3.04719E-03    ( -0.00143398   0.00121794 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   62.47     using 59 bins.
 Reduced chi-squared = 1.09596
# Null hypothesis probability of 2.88e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 0.437306 ( -0.136468  0.136276 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.80046e-08 ( -1.13333e-08  1.22801e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    3.120 sec. to    4.120 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -3.44163     ( -0.480888   1.71751 )
Epeak [keV] : 382.208      (   )
Norm@50keV  : 5.77569E-04    (     )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   59.99     using 59 bins.
 Reduced chi-squared = 1.07125
# Null hypothesis probability of 3.33e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 0.287310 ( -0.163216  0.22057 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.31627e-08 ( -1.35186e-08  7.142e-09 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 177.884 sec.
Hardness ratio (energy fluence ratio) = 1.30008002653

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

S(15-50 keV)  = 5.868499e-07
S(50-150 keV) = 8.268004e-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 = -2.548909428459438E-02, IMY = -8.039038628206906E-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:
-239.000000 -6.792000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
244.9951 -15.6306    0.6  29.7  139.1   9.9835  18.5    1.1	Sco X-1                       
254.3045  35.3829    8.4  31.2   20.2   0.6427   1.4    7.9	Her X-1                       
268.2502  -1.3621    3.9  37.8   91.5   3.4629   3.0    8.9	SW J1753.5-0127               
268.4748  50.3790    2.4  49.0   14.1   3.3059   4.8 ------	UNKNOWN                       
267.6640  62.0164    3.3  56.7    3.2   5.1453   3.5 ------	UNKNOWN                       
192.8743  41.0425    3.7  45.6  -57.9   5.0558   3.2 ------	UNKNOWN                       
188.6090  -9.2770    3.2  48.1 -129.3   5.9852   3.6 ------	UNKNOWN                       

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

Time interval of the image:
-6.792000 73.100600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
245.0247 -15.7910    5.3  29.8  139.2  -0.3755  -2.2    9.4	Sco X-1                       
254.3837  35.3046    3.7  31.2   20.4   0.4811   3.1    4.3	Her X-1                       
268.2185  -1.4256   30.5  37.8   91.6  -0.1553  -0.4    9.1	SW J1753.5-0127               
236.4509   8.6116    0.7   4.8  107.6   1.7692  15.5 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
106.300600 744.700600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
244.9845 -15.6352    0.5  25.7  138.3  26.0308  21.7    0.4	Sco X-1                       
254.5447  35.4744    9.1  31.5    6.5   1.4354   1.3    9.0	Her X-1                       
263.0649 -24.8157    7.9  42.3  120.4  -7.8877  -1.5    5.2	GX 1+4                        
268.4793  -1.5725    8.5  33.5   83.8   2.7661   1.4    9.8	SW J1753.5-0127               
275.3428  44.0298    3.6  48.9   14.4   4.9992   3.2 ------	UNKNOWN                       
244.7036  15.9240    3.5  10.9   24.6   2.7142   3.3 ------	UNKNOWN                       
208.1406 -42.4347    2.7  57.2 -177.8  17.8136   4.3 ------	UNKNOWN                       
193.3771 -34.8972    3.1  59.6 -161.9  30.0885   3.7 ------	UNKNOWN                       
202.0626  42.9029    3.4  45.6  -57.8  15.5894   3.4 ------	UNKNOWN                       
190.6191  -6.4523    3.5  48.1 -129.2  14.7555   3.3 ------	UNKNOWN