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
37.0569 19.1804 0.0156 31.5280 140.9228 1.2253395 12.403 TRIG_01278305
Foreground time interval of the image:
-0.224 35.637 (delta_t = 35.861 [sec])
Background time interval of the image:
-239.864 -0.224 (delta_t = 239.640 [sec])
Lightcurves
Notes:
- 1) The mask-weighted light curves are using the flight position.
- 2) Multiple plots of different time binning/intervals are shown to cover all scenarios of short/long GRBs, rate/image triggers, and real/false positives.
- 3) For all the mask-weighted lightcurves, the y-axis units are counts/sec/det where a det is 0.4 x 0.4 = 0.16 sq cm.
- 4) The verticle lines correspond to following: green dotted lines are T50 interval, black dotted lines are T90 interval, blue solid line(s) is a spacecraft slew start time, and orange solid line(s) is a spacecraft slew end time.
- 5) Time of each bin is in the middle of the bin.
1 s binning
From T0-310 s to T0+310 s
From T100_start - 20 s to T100_end + 30 s
Full time interval
64 ms binning
Full time interval
From T100_start to T100_end
From T0-5 sec to T0+5 sec
16 ms binning
From T100_start-5 s to T100_start+5 s
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 4.096000
8 ms binning
From T100_start-3 s to T100_start+3 s
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 4.096000
2 ms binning
From T100_start-1 s to T100_start+1 s
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 4.096000
SN=5 or 10 sec. binning (whichever binning is satisfied first)
SN=5 or 10 sec. binning (T < 200 sec)
Quad-rate summed light curves (from T0-300s to T0+1000s)
Spectral Evolution
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 -0.224 sec. to 36.488 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.11935 ( -0.233061 0.251877 )
Norm@50keV : 1.85056E-03 ( -0.000320925 0.000312301 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 58.39 using 59 bins.
Reduced chi-squared = 1.02439
# Null hypothesis probability of 4.24e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 36.71 sec: 0.293978 ( -0.037028 0.037031 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.32535e-07 ( -9.66593e-08 9.92176e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.224 sec. to 36.488 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.56677 ( -1.21276 0.737219 )
Epeak [keV] : 30.8554 ( -29.078 -30.8555 )
Norm@50keV : 3.98547E-03 ( -0.00398555 0.018304 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 57.41 using 59 bins.
Reduced chi-squared = 1.02518
# Null hypothesis probability of 4.23e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 36.71 sec: 0.289204 ( -0.03784 0.037871 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.9678e-07 ( -1.07864e-07 1.1544e-07 ) ergs/cm2
Band function
Time interval is from -0.224 sec. to 36.488 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : ( )
beta : ( )
Epeak [keV] : ( )
Norm@50keV : ( )
------------------------------------------------------------
Photon flux (15-150 keV) in sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 8.67169 (-1.26458 1.48369)
R^2/D10^2 : 0.235562 (-0.108731 0.203359)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared 69.26 using 59 bins.
Reduced chi-squared =
# Null hypothesis probability of 1.28e-01 with 57 degrees of freedom
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.240e-07 2.698e-08
25- 50 2.485e-07 4.600e-08
50-150 8.451e-08 3.230e-08
15-150 4.571e-07 8.051e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 52.6599 (-15.7998 27.3393)
Norm : 1.62827 (-0.325147 0.440045)
------------------------------------------------------------
#Fit statistic : Chi-Squared 57.53 using 59 bins.
Reduced chi-squared =
# Null hypothesis probability of 4.55e-01 with 57 degrees of freedom
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.478e-07 2.454e-08
25- 50 2.162e-07 3.060e-08
50-150 2.202e-07 8.366e-08
15-150 5.842e-07 1.177e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 5.62049 (-1.67639 1.85063)
R1^2/D10^2 : 0.967743 (-0.612764 1.05557)
kT2 [keV] : 18.7410 (-6.55224 19.766)
R2^2/D10^2 : 7.39908E-03 (-0.00686422 0.0391414)
------------------------------------------------------------
#Fit statistic : Chi-Squared 56.49 using 59 bins.
Reduced chi-squared =
# Null hypothesis probability of 4.19e-01 with 55 degrees of freedom
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.538e-07 8.089e-08
25- 50 2.061e-07 1.066e-07
50-150 2.391e-07 1.401e-07
15-150 5.990e-07 2.806e-07
Peak spectrum fit
Power-law model
Time interval is from 0.952 sec. to 1.952 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.29485 ( -0.362831 0.35045 )
Norm@50keV : 7.07963E-03 ( -0.00173024 0.00173019 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 59.29 using 59 bins.
Reduced chi-squared = 1.04018
# Null hypothesis probability of 3.92e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 0.843734 ( -0.212586 0.213996 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.00664e-08 ( -1.79781e-08 1.81644e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.952 sec. to 1.952 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.78585 ( -4.52247 2.23678 )
Epeak [keV] : 61.4982 ( -12.2024 33.1864 )
Norm@50keV : 0.237860 ( -0.263865 32.0058 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 52.49 using 59 bins.
Reduced chi-squared = 0.937321
# Null hypothesis probability of 6.09e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 0.792061 ( -0.214824 0.218069 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.10225e-08 ( -1.72783e-08 1.89665e-08 ) ergs/cm2
Band function
Time interval is from 0.952 sec. to 1.952 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : ( )
beta : ( )
Epeak [keV] : ( )
Norm@50keV : ( )
------------------------------------------------------------
Photon flux (15-150 keV) in sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 16.0428 (-3.08807 4.12211)
R^2/D10^2 : 9.09366E-02 (-0.0512754 0.10147)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared 52.60 using 59 bins.
Reduced chi-squared =
# Null hypothesis probability of 6.41e-01 with 57 degrees of freedom
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.836e-09 2.301e-09
25- 50 2.040e-08 8.744e-09
50-150 3.673e-08 1.744e-08
15-150 6.197e-08 2.439e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 199.359 (-92.7803 -199.363)
Norm : 3.59103 (-0.876248 0.878576)
------------------------------------------------------------
#Fit statistic : Chi-Squared 59.24 using 59 bins.
Reduced chi-squared =
# Null hypothesis probability of 3.94e-01 with 57 degrees of freedom
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 8.942e-09 5.375e-09
25- 50 1.720e-08 1.062e-08
50-150 3.773e-08 2.243e-08
15-150 6.387e-08 3.815e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 200.000 (-200 -200)
R1^2/D10^2 : 2.36100E-05 (-2.36108e-05 -2.36108e-05)
kT2 [keV] : 15.2521 (-3.6908 4.76023)
R2^2/D10^2 : 0.103593 (-0.062868 0.0848697)
------------------------------------------------------------
#Fit statistic : Chi-Squared 52.44 using 59 bins.
Reduced chi-squared =
# Null hypothesis probability of 5.73e-01 with 55 degrees of freedom
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.870e-09 1.952e-05
25- 50 2.036e-08 1.636e-04
50-150 3.683e-08 4.019e-03
15-150 6.206e-08 3.915e-03
Pre-slew spectrum (Pre-slew PHA with pre-slew DRM)
Power-law model
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.16010 ( -0.238517 0.258765 )
Norm@50keV : 1.82032E-03 ( -0.000327048 0.000318356 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 61.35 using 59 bins.
Reduced chi-squared =
# Null hypothesis probability of 3.23e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 35.86 sec: 0.295180 ( -0.0375817 0.0375831 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.10513e-07 ( -9.47565e-08 9.75155e-08 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.56560 ( -1.28348 0.682945 )
Epeak [keV] : 28.3386 ( -26.2534 -28.3401 )
Norm@50keV : 4.18417E-03 ( -0.00418478 0.0222097 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 60.31 using 59 bins.
Reduced chi-squared =
# Null hypothesis probability of 3.23e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 35.86 sec: 0.290075 ( -0.038389 0.038453 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.73724e-07 ( -1.05263e-07 1.14182e-07 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : ( )
beta : ( )
Epeak [keV] : ( )
Norm@50keV : ( )
------------------------------------------------------------
Photon flux (15-150 keV) in sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
S(25-50 keV) vs. S(50-100 keV) plot
S(25-50 keV) = 1.97e-07
S(50-100 keV) = 1.81e-07
T90 vs. Hardness ratio plot
T90 = 34.2159999608994 sec.
Hardness ratio (energy fluence ratio) = 0.918782
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.03282
Count Ratio (50-100 keV) / (15-25 keV) = 0.491345
Mask shadow pattern
IMX = -4.762372881367050E-01, IMY = -3.867131623391962E-01
TIME vs. PHA plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 4.096000
TIME vs. DetID plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 4.096000
100 us light curve (15-350 keV)
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 4.096000
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:
-239.864000 -0.224000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
326.1859 38.3198 46.9 34.3 -68.0 0.1250 0.2 0.7 Cyg X-2
267.1220 64.9890 3.4 58.1 -16.2 3.8276 3.3 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-0.224000 35.636600
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
326.0259 38.3867 39.4 34.4 -67.8 -0.0345 -0.3 7.9 Cyg X-2
50.7756 11.3307 2.3 46.0 132.6 1.4949 5.1 ------ UNKNOWN
37.0569 19.1804 0.9 31.5 140.9 1.2250 12.4 ------ UNKNOWN
352.5243 30.8171 2.5 18.7 -107.7 0.3497 4.6 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
110.036600 931.997200
933.136000 942.836600
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
76.4176 45.9501 2.5 41.9 57.7 15.8464 4.6 ------ UNKNOWN
70.0927 31.4941 2.8 32.1 77.3 7.7173 4.1 ------ UNKNOWN
65.8074 34.4706 3.1 29.7 69.6 6.3285 3.7 ------ UNKNOWN
1.5380 13.9130 2.8 34.4 -76.9 7.5371 4.1 ------ UNKNOWN
10.2721 -21.0358 2.2 48.0 -129.1 22.4720 5.3 ------ UNKNOWN
Plot creation:
Mon Jun 30 16:47:53 EDT 2025