GRB250430A

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 20:51:16 EDT 2025
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1308754
======================================================================

  Trigger: 01308754      Segment: 000

  BAT Trigger Time: 767727095.808   [s; MET]
      Trigger Stop: 767727096.832   [s; MET]
               UTC: 2025-04-30T17:31:00.286960    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 233.428106944477   Dec: -18.0833375040458  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    13.49
     Image Trigger?:     NO
     Rate S/N Ratio:     32.2490309931942  [ if not an image trigger ]
     Image S/N Ratio:    13.49

  Analysis Position:   [ source = BAT ]
    RA: 233.428106944477   Dec: -18.0833375040458  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 233.396160681923   Dec: -18.0987134615337  [deg; J2000]  
        { 15h 33m 35.1s , -18d 05' 55.4" }
         +/- 1.10388953387949 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.388471131464108 [arcmin] (formal 1-sigma fit error)
    SNR: 26.4116827350185
 
  Angular difference between the analysis and refined position is 2.042269 arcmin
 
  Partial Coding Fraction: 0.7265625    [ including projection effects ]

  Duration
     T90: 53.8359999656677 +/- 140.923381574302
        Measured from: 0.407999992370605
                   to: 54.2439999580383     [s; relative to TRIGTIME]
     T50: 6.94799995422363 +/- 39.4935127351029
        Measured from: 1.90400004386902
                   to: 8.85199999809265     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.308000087738037     
                   to: 1.30800008773804     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.0679999589920044     
                   to: 234.016000032425     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.497117   0.648341   0.374027   0.091069
           0.108354   0.097234   0.078266   0.063162 [error]
 Peak      0.065071   0.110868   0.087509   0.029222
           0.009111   0.009304   0.008234   0.006360 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  234.084   -0.068  234.016
T90    53.836    0.408   54.244
T50     6.948    1.904    8.852
Peak    1.000    0.308    1.308
 
 
====== 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      -1.920    -0.322      0.300       -           -               -         4.02e-04     -8.35e-05          8.13e-05      58.260   57
CPL     -0.477    -1.395      1.954       46.394     -17.188        58.772      2.52e-03     -2.52e-03          2.74e-02      55.140   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      -1.327     -0.161     0.161       -           -               -         1.91e-02     -1.81e-03          1.81e-03      64.700   57
CPL     -0.470     -0.374     0.830       92.681     -23.866       152.739      4.98e-02     -2.64e-02          7.39e-02      60.050   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   1.78e-07  2.54e-07  2.68e-07  5.25e-07  8.65e-07  1.23e-06   erg/cm2
      90%_error_low -4.38e-08 -4.43e-08 -7.30e-08 -2.38e-07 -1.72e-07 -3.30e-07   erg/cm2
      90%_error_hi   4.61e-08  4.43e-08  7.48e-08  3.41e-07  1.77e-07  4.07e-07   erg/cm2
Peak flux       PL   6.66e-01  7.42e-01  5.92e-01  7.81e-01  2.29e+00  2.78e+00   ph/cm2/s
      90%_error_low -1.11e-01 -7.91e-02 -6.74e-02 -1.70e-01 -2.22e-01 -2.71e-01   ph/cm2/s
      90%_error_hi   1.18e-01  7.84e-02  6.68e-02  1.97e-01  2.22e-01  2.74e-01   ph/cm2/s
 
Fluence        CPL   1.51e-07  2.96e-07  2.63e-07  8.85e-08  7.78e-07  7.99e-07   erg/cm2
      90%_error_low -5.32e-08 -6.02e-08 -9.11e-08 -7.47e-08 -1.69e-07 -1.87e-07   erg/cm2
      90%_error_hi   5.40e-08  6.32e-08  8.79e-08  3.99e-07  1.89e-07  4.18e-07   erg/cm2
Peak flux      CPL   5.57e-01  7.92e-01  6.36e-01  3.44e-01  2.20e+00  2.33e+00   ph/cm2/s
      90%_error_low -1.35e-01 -9.19e-02 -7.84e-02 -1.64e-01 -2.33e-01 -2.94e-01   ph/cm2/s
      90%_error_hi   1.43e-01  9.47e-02  8.02e-02  3.16e-01  2.33e-01  3.76e-01   ph/cm2/s
 
======================================================================

Special notes of this burst

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  233.3962   -18.0987   0.0073    22.0425   135.4348         1.6436622     26.412 TRIG_01308754                 
 
Foreground time interval of the image:
 -0.068  15.893 (delta_t =  15.961 [sec])
Background time interval of the image:
-89.507  -0.068 (delta_t =  89.439 [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

Bokeh Plot

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   -0.068 sec. to  234.016 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.91956     ( -0.322453   0.30016 )
Norm@50keV  : 4.01604E-04    ( -8.35425e-05   8.12833e-05 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   58.26     using 59 bins.
 Reduced chi-squared = 1.02211
# Null hypothesis probability of 4.29e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 234.1 sec: 5.81223E-02 ( -0.0102403  0.0102558 ) ph/cm2/s
Energy fluence (15-150 keV)             : 8.64733e-07 ( -1.72214e-07  1.76677e-07 ) ergs/cm2

Cutoff power-law model

Time interval is from   -0.068 sec. to  234.016 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.477251     ( -1.39599   1.95263 )
Epeak [keV] : 46.3941      ( -17.1907 58.7698 )
Norm@50keV  : 2.51528E-03    ( -0.002519   0.027424 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   55.14     using 59 bins.
 Reduced chi-squared = 0.984643
# Null hypothesis probability of 5.08e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 234.1 sec: 5.50171E-02 ( -0.0106448  0.0106788 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.78184e-07 ( -1.68897e-07  1.89028e-07 ) ergs/cm2

1-s peak spectrum fit

Power-law model

Time interval is from    0.308 sec. to    1.308 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.32742     ( -0.161027   0.161212 )
Norm@50keV  : 1.90791E-02    ( -0.00181046   0.00180903 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   64.70     using 59 bins.
 Reduced chi-squared = 1.13509
# Null hypothesis probability of 2.26e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 2.28809 ( -0.22153  0.22197 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.87331e-07 ( -1.96476e-08  1.98071e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from    0.308 sec. to    1.308 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.470378     ( -0.373775   0.829721 )
Epeak [keV] : 92.6809      ( -23.8656 152.739 )
Norm@50keV  : 4.97886E-02    ( -0.0263687   0.0739297 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   60.05     using 59 bins.
 Reduced chi-squared = 1.07232
# Null hypothesis probability of 3.31e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 2.20022 ( -0.23304  0.2329 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.76466e-07 ( -2.19263e-08  2.18876e-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.

 IMX = -2.884642626841660E-01,

Spacecraft aspect plot

Bright

Pre-burst

 Time interval of the image: -89.507400 -0.068000

# RAcent #  [deg] 170.0917 -60.5568 186.8366 -62.9365 244.9893 -15.6425 255.9366 -37.8598 256.3925 -36.4066 262.9864 -24.7749 264.9385 -44.5025 270.1610 -25.1885 270.2785 -25.7622 274.0258 -14.0384 275.9229 -30.3639 285.0712 -24.7621 263.1587 -33.7847 248.5424 -47.4090 288.7144 -47.0691

Pre-slew

 Time interval of the image: -0.068000 15.892600

# RAcent #  [deg] 170.3747 -60.6027 186.4424 -62.6529 244.8942 -15.6763 255.8131 -37.9006 256.5239 -36.2405 263.0916 -24.5900 264.7270 -44.2964 270.2129 -25.0060 270.2684 -25.7007 273.8627 -14.0948 275.8954 -30.2530 285.1093 -24.9703 263.1909 -33.8743 233.3962 -18.0987 269.3074 -11.9554 153.7388 -21.1033 166.4544 -43.2015 282.6341 -57.8329

Post-slew

 Time interval of the image: 137.092600 962.212000

# RAcent #  [deg] 186.7464 -62.7924 244.9665 -15.6277 254.5547  35.3837 256.0779 -37.8991 256.4652 -36.3206 262.8433 -24.6200 264.9296 -44.2782 268.4314  -1.4018 270.4277 -25.0399 270.1919 -25.8590 273.9146 -13.9183 275.9591 -30.4042 262.8145 -33.9505 199.7414 -16.9159 217.4020 -65.3942 238.0885   6.4514 248.4692 -47.4274

Mask shadow pattern

IMY = -2.841189498997055E-01 source in the pre-burst/pre-slew/post-slew images image of 15-350 keV band DECcent POSerr Theta Phi PeakCts SNR AngSep Name [deg] ['] [deg] [deg] ['] 12.0 39.4 -53.9 -0.3108 -1.0 7.7 Cen X-3 7.6 33.7 -63.9 0.3839 1.5 11.1 GX 301-2 0.7 31.3 150.3 3.8748 16.3 0.6 Sco X-1 1.7 30.9 -161.8 1.3524 6.8 2.5 4U 1700-377 5.1 31.4 -164.5 0.4495 2.3 2.3 GX 349+2 8.0 40.4 179.5 0.3743 1.4 2.1 GX 1+4 4.2 37.1 -149.0 -0.6744 -2.7 8.9 4U 1735-44 17.9 46.1 -175.9 -0.2397 -0.6 9.4 GX 5-1 67.6 45.9 -175.1 0.0630 0.2 1.7 GRS 1758-258 27.4 54.7 173.8 -0.2548 -0.4 1.2 GX 17+2 82.3 48.7 -166.7 -0.0576 -0.1 0.2 H1820-303 3.0 58.4 -168.8 -3.8635 -4.0 9.7 HT1900.1-2455 3.7 37.4 -166.9 0.6720 3.1 9.0 GX 354-0 2.3 26.2 -140.8 0.9121 5.0 ------ UNKNOWN 2.3 53.2 -142.2 4.0970 5.1 ------ UNKNOWN background subtracted image of 15-350 keV band DECcent POSerr Theta Phi PeakCts SNR AngSep Name [deg] ['] [deg] [deg] ['] 5.0 39.3 -54.0 0.2537 2.3 2.1 Cen X-3 6.9 33.7 -63.3 0.1403 1.7 9.2 GX 301-2 3.3 31.2 150.2 -0.2662 -3.5 5.4 Sco X-1 3.7 30.8 -161.7 -0.2022 -3.1 8.9 4U 1700-377 4.8 31.5 -164.8 -0.1588 -2.4 11.8 GX 349+2 200.4 40.6 179.3 -0.0050 -0.1 10.4 GX 1+4 17.8 37.0 -149.4 0.0518 0.7 9.2 4U 1735-44 4.2 46.2 -176.1 0.2964 2.7 5.9 GX 5-1 16.0 46.0 -175.2 -0.0767 -0.7 3.1 GRS 1758-258 7.7 54.6 173.8 -0.3842 -1.5 9.0 GX 17+2 14.9 48.7 -166.8 -0.0932 -0.8 7.0 H1820-303 24.2 58.3 -168.6 -0.1508 -0.5 5.0 HT1900.1-2455 9.0 37.4 -166.8 0.0915 1.3 10.3 GX 354-0 0.4 22.0 135.4 1.6436 26.4 ------ UNKNOWN 2.3 52.1 168.5 1.0442 5.1 ------ UNKNOWN 1.9 57.0 -2.5 1.7866 6.0 ------ UNKNOWN 2.5 39.8 -26.3 0.3714 4.6 ------ UNKNOWN 2.2 48.0 -129.1 1.2327 5.2 ------ UNKNOWN image of 15-350 keV band DECcent POSerr Theta Phi PeakCts SNR AngSep Name [deg] ['] [deg] [deg] ['] 6.0 54.9 14.5 -7.1782 -1.9 2.8 GX 301-2 0.4 11.3 -110.3 30.3365 26.2 1.1 Sco X-1 4.6 57.1 -169.0 11.4638 2.5 5.4 Her X-1 2.2 28.0 -49.8 7.8430 5.2 5.4 4U 1700-377 6.1 27.3 -52.9 2.5884 1.9 6.3 GX 349+2 0.0 28.1 -80.9 4.2682 2.7 11.8 GX 1+4 0.0 37.2 -47.7 2.1426 1.1 13.1 4U 1735-44 3.6 38.2 -121.4 -6.8177 -3.2 4.9 SW J1753.5-0127 132.8 35.0 -81.4 -0.2159 -0.1 8.1 GX 5-1 14.1 34.9 -80.0 1.9731 0.8 9.2 GRS 1758-258 3.9 39.1 -99.5 11.8446 3.0 8.9 GX 17+2 4.5 40.4 -73.5 11.2393 2.6 2.8 H1820-303 4.8 30.6 -62.5 3.8058 2.4 11.1 GX 354-0 3.1 32.1 77.4 9.5165 3.7 ------ UNKNOWN 2.5 48.5 -0.6 9.8130 4.7 ------ UNKNOWN 3.2 25.0 -178.4 4.1785 3.7 ------ UNKNOWN 2.5 31.8 -28.9 6.5705 4.7 ------ UNKNOWN

Analysis Summary

Notes:

Image

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

Light Curves

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:

Time averaged spectrum fit using the average DRM

Power-law model

Cutoff power-law model

1-s peak spectrum fit

Power-law model

Cutoff power-law model

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

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

IMX = -2.884642626841660E-01,

Spacecraft aspect plot

Bright

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