GRB250516A: 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: Thu Jun 19 20:41:30 EDT 2025
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1314210
======================================================================

  Trigger: 01314210      Segment: 000

  BAT Trigger Time: 769098964.544   [s; MET]
      Trigger Stop: 769098965.056   [s; MET]
               UTC: 2025-05-16T14:35:28.929340    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 334.561458739418   Dec: -9.13022768057874  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    8.41
     Image Trigger?:     NO
     Rate S/N Ratio:     14.3874945699382  [ if not an image trigger ]
     Image S/N Ratio:    8.41

  Analysis Position:   [ source = BAT ]
    RA: 334.561458739418   Dec: -9.13022768057874  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 334.611559596065   Dec: -9.11996954812633  [deg; J2000]  
        { 22h 18m 26.8s , -09d 07' 11.9" }
         +/- 1.07394794527236 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.402084291614899 [arcmin] (formal 1-sigma fit error)
    SNR: 27.4698710535286
 
  Angular difference between the analysis and refined position is 3.031154 arcmin
 
  Partial Coding Fraction: 0.6171875    [ including projection effects ]

  Duration
     T90: 30.0360000133514 +/- 6.009781712102
        Measured from: -8.87600004673004
                   to: 21.1599999666214     [s; relative to TRIGTIME]
     T50: 11.2279999256134 +/- 3.18612302278263
        Measured from: 2.68400001525879
                   to: 13.9119999408722     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 19.3880000114441     
                   to: 20.3880000114441     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -19.960000038147     
                   to: 22.6959999799728     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     1.068443   1.448206   0.940731   0.288810
           0.052782   0.055930   0.047726   0.038384 [error]
 Peak      0.121305   0.161182   0.117846   0.035667
           0.010070   0.011399   0.009887   0.007016 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   42.656  -19.960   22.696
T90    30.036   -8.876   21.160
T50    11.228    2.684   13.912
Peak    1.000   19.388   20.388
 
 
====== 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      -1.690    -0.085      0.084       -           -               -         5.89e-03     -2.77e-04          2.77e-04      63.090   57
CPL     -1.691    -0.083      0.088     9999.320    -9999.310      -9999.320      5.88e-03     -2.58e-04          2.17e-03      63.100   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      -1.576     -0.131     0.130       -           -               -         2.95e-02     -2.29e-03          2.27e-03      40.280   57
CPL     -1.577     -0.129     0.133     9999.360    -9999.360      -9999.360      2.95e-02     -2.95e-02          1.48e-02      40.290   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   3.83e-07  6.27e-07  7.78e-07  1.91e-06  2.33e-06  3.70e-06   erg/cm2
      90%_error_low -3.08e-08 -3.03e-08 -4.84e-08 -2.46e-07 -1.15e-07 -2.84e-07   erg/cm2
      90%_error_hi   3.16e-08  3.03e-08  4.83e-08  2.70e-07  1.15e-07  3.02e-07   erg/cm2
Peak flux       PL   1.31e+00  1.26e+00  8.44e-01  8.84e-01  3.77e+00  4.29e+00   ph/cm2/s
      90%_error_low -1.65e-01 -1.01e-01 -8.22e-02 -1.64e-01 -2.90e-01 -3.22e-01   ph/cm2/s
      90%_error_hi   1.71e-01  9.98e-02  8.14e-02  1.84e-01  2.90e-01  3.23e-01   ph/cm2/s
 
Fluence        CPL   3.84e-07  6.26e-07  7.76e-07  1.93e-06  2.33e-06  3.75e-06   erg/cm2
      90%_error_low    N/A    -3.01e-08 -5.21e-08 -1.44e-07 -1.22e-07 -8.29e-07   erg/cm2
      90%_error_hi     N/A     3.49e-08  5.48e-08  2.83e-07  1.15e-07  1.38e-07   erg/cm2
Peak flux      CPL   1.31e+00  1.25e+00  8.40e-01  9.17e-01  3.78e+00  4.34e+00   ph/cm2/s
      90%_error_low -1.91e-01 -1.03e-01 -8.53e-02 -9.17e-01 -3.82e-01 -4.25e-01   ph/cm2/s
      90%_error_hi   1.74e-01  1.15e-01  9.37e-02  2.72e-01  3.57e-01  2.83e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  334.6116    -9.1200   0.0070    38.1231  -159.7447         2.5247048     27.470 TRIG_01314210                 
 
Foreground time interval of the image:
-19.960   9.957 (delta_t =  29.917 [sec])
Background time interval of the image:
-239.544 -19.960 (delta_t = 219.584 [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  -19.960 sec. to   22.696 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.68959     ( -0.0849784   0.0843909 )
Norm@50keV  : 5.88547E-03    ( -0.000277459   0.000276597 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   63.09     using 59 bins.
 Reduced chi-squared = 1.10684
# Null hypothesis probability of 2.70e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 42.66 sec: 0.778867 ( -0.037843  0.037975 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.32697e-06 ( -1.14585e-07  1.14946e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from  -19.960 sec. to   22.696 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.69063     ( -0.083845   0.0866392 )
Epeak [keV] : 9999.32      ( -9999.35 -9999.36 )
Norm@50keV  : 5.88058E-03    ( -0.000271165   0.00216102 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   63.10     using 59 bins.
 Reduced chi-squared = 1.12679
# Null hypothesis probability of 2.40e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 42.66 sec: 0.779532 ( -0.039266  0.037916 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.32912e-06 ( -1.22124e-07  1.14769e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   19.388 sec. to   20.388 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.57597     ( -0.130919   0.129558 )
Norm@50keV  : 2.95216E-02    ( -0.00228531   0.00227318 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   40.28     using 59 bins.
 Reduced chi-squared = 0.706667
# Null hypothesis probability of 9.54e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 3.76609 ( -0.28963  0.29001 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.76968e-07 ( -2.2976e-08  2.31071e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   19.388 sec. to   20.388 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.57703     ( -0.129311   0.132748 )
Epeak [keV] : 9999.36      ( -9999.36 -9999.36 )
Norm@50keV  : 2.95470E-02    ( -0.0295865   0.0147512 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   40.29     using 59 bins.
 Reduced chi-squared = 0.719464
# Null hypothesis probability of 9.44e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 3.77747 ( -0.38201  0.35731 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.78356e-07 ( -3.24948e-08  2.98137e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 30.036 sec.
Hardness ratio (energy fluence ratio) = 1.24008103415

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

S(15-50 keV)  = 1.0103177e-06
S(50-150 keV) = 1.3166232e-06

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 = -7.362225741987247E-01, IMY = 2.716847853550358E-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:
-239.544000 -19.960000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
330.0989  -9.8006    2.1  37.4 -167.0   2.0749   5.6 ------	UNKNOWN                       
342.1997   1.4864    3.5  49.4 -150.4   2.5856   3.3 ------	UNKNOWN                       

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

Time interval of the image:
-19.960000 9.956590
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
334.4593 -23.7461    2.3  23.5 -158.5   0.3159   4.9 ------	UNKNOWN                       
334.6116  -9.1200    0.4  38.1 -159.7   2.5247  27.5 ------	UNKNOWN                       
 27.8595 -61.5366    2.4  34.1  -27.9   0.3957   4.7 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
87.356600 962.576000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
308.2254  40.9366   87.9  55.6  177.1   0.5923   0.1    5.3	Cyg X-3                       
326.2050  38.4804    8.3  48.2 -167.7  -3.7555  -1.4    9.7	Cyg X-2                       
297.7690   1.0692    2.6  38.1  124.7  12.8553   4.5 ------	UNKNOWN                       
313.7547  39.0437    3.1  51.9 -179.4  12.3636   3.7 ------	UNKNOWN                       
329.0223  27.9014    2.3  37.4 -167.0   6.7773   5.0 ------	UNKNOWN                       
351.3335  -3.0333    2.7  17.7  -88.0   5.1085   4.2  550.7	UNKNOWN                       
  1.5182  26.5604    2.5  44.2 -123.4  22.5754   4.6 ------	UNKNOWN                       
 16.9086  -5.1677    2.0  42.2  -71.3  26.1389   5.8 ------	UNKNOWN