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
105.3539 -25.8678 0.0092 37.1700 104.0873 3.9702804 21.001 TRIG_00252593
Foreground time interval of the image:
35.112 76.701 (delta_t = 41.589 [sec])
Background time interval of the image:
-239.000 35.112 (delta_t = 274.112 [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 64.000000
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 64.000000
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 64.000000
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 35.112 sec. to 84.888 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.95614 ( -0.127104 0.131039 )
Norm@50keV : 4.96139E-03 ( -0.000413831 0.000408409 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.93 using 59 PHA bins.
# Reduced chi-squared = 0.9111 for 57 degrees of freedom
# Null hypothesis probability = 6.650816e-01
Photon flux (15-150 keV) in 49.78 sec: 0.729593 ( -0.052369 0.05242 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.27331e-06 ( -1.82449e-07 1.84194e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 35.112 sec. to 84.888 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.30598 ( -0.56903 0.503173 )
Epeak [keV] : 47.2940 ( -11.3593 20.5878 )
Norm@50keV : 1.13536E-02 ( -0.00527163 0.0119136 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.87 using 59 PHA bins.
# Reduced chi-squared = 0.8370 for 56 degrees of freedom
# Null hypothesis probability = 8.024168e-01
Photon flux (15-150 keV) in 49.78 sec: 0.709890 ( -0.054366 0.054402 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.15417e-06 ( -1.99787e-07 2.03804e-07 ) ergs/cm2
Band function
Time interval is from 35.112 sec. to 84.888 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.30608 ( -0.269773 0.991163 )
beta : -10.0000 ( 10 1.77636e-15 )
Epeak [keV] : 47.2854 ( -11.3463 20.5924 )
Norm@50keV : 1.13508E-02 ( -0.00527007 0.0119206 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.87 using 59 PHA bins.
# Reduced chi-squared = 0.8522 for 55 degrees of freedom
# Null hypothesis probability = 7.740375e-01
Photon flux (15-150 keV) in 49.78 sec: 0.713365 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 2.15719e-06 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 10.7723 (-0.948199 1.04526)
R^2/D10^2 : 0.253681 (-0.0756414 0.107454)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 88.13 using 59 PHA bins.
# Reduced chi-squared = 1.546 for 57 degrees of freedom
# Null hypothesis probability = 5.111131e-03
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.048e-07 4.199e-08
25- 50 8.388e-07 7.069e-08
50-150 5.409e-07 9.269e-08
15-150 1.685e-06 1.394e-07
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 74.4395 (-14.7978 21.0193)
Norm : 3.50220 (-0.383006 0.439822)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 46.87 using 59 PHA bins.
# Reduced chi-squared = 0.8222 for 57 degrees of freedom
# Null hypothesis probability = 8.285246e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.499e-07 4.615e-08
25- 50 7.275e-07 5.202e-08
50-150 9.771e-07 1.702e-07
15-150 2.155e-06 2.076e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 5.91729 (-1.1109 1.19859)
R1^2/D10^2 : 1.67938 (-0.807135 1.99115)
kT2 [keV] : 19.3643 (-3.3981 5.13452)
R2^2/D10^2 : 1.94814E-02 (-0.0120436 0.0244043)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.17 using 59 PHA bins.
# Reduced chi-squared = 0.8031 for 55 degrees of freedom
# Null hypothesis probability = 8.519040e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.521e-07 1.241e-07
25- 50 7.147e-07 1.849e-07
50-150 9.886e-07 4.761e-07
15-150 2.155e-06 6.944e-07
Peak spectrum fit
Power-law model
Time interval is from 59.276 sec. to 60.276 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.16155 ( -0.367687 0.416047 )
Norm@50keV : 9.23484E-03 ( -0.00280727 0.00274968 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.32 using 59 PHA bins.
# Reduced chi-squared = 1.111 for 57 degrees of freedom
# Null hypothesis probability = 2.631481e-01
Photon flux (15-150 keV) in 1 sec: 1.49862 ( -0.342526 0.342527 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.63678e-08 ( -2.30055e-08 2.40073e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 59.276 sec. to 60.276 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -6.74355E-02 ( -3.10604 1.91846 )
Epeak [keV] : 33.3891 ( -19.3434 12.727 )
Norm@50keV : 0.238095 ( -0.248155 39.5482 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.20 using 59 PHA bins.
# Reduced chi-squared = 1.057 for 56 degrees of freedom
# Null hypothesis probability = 3.597389e-01
Photon flux (15-150 keV) in 1 sec: 1.47595 ( -0.33302 0.3357 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.45704e-08 ( -1.99607e-08 2.32447e-08 ) ergs/cm2
Band function
Time interval is from 59.276 sec. to 60.276 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.97963 ( -4.51519 -4.97963 )
beta : -2.92247 ( -1.33669 0.68323 )
Epeak [keV] : 25.9667 ( -4.93924 4.47358 )
Norm@50keV : 1561.93 ( -334.844 4823.04 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.24 using 59 PHA bins.
# Reduced chi-squared = 1.023 for 55 degrees of freedom
# Null hypothesis probability = 4.281274e-01
Photon flux (15-150 keV) in 1 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 8.02787e-08 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 8.42771 (-1.90637 2.33736)
R^2/D10^2 : 1.46449 (-0.913343 2.5563)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.36 using 59 PHA bins.
# Reduced chi-squared = 1.059 for 57 degrees of freedom
# Null hypothesis probability = 3.553750e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.950e-08 9.356e-09
25- 50 3.728e-08 1.491e-08
50-150 1.158e-08 7.147e-09
15-150 6.836e-08 2.678e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 45.0919 (-17.9405 39.082)
Norm : 9.34974 (-3.0035 4.5355)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.51 using 59 PHA bins.
# Reduced chi-squared = 1.062 for 57 degrees of freedom
# Null hypothesis probability = 3.503333e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.227e-08 6.320e-09
25- 50 3.078e-08 1.186e-08
50-150 2.701e-08 1.720e-08
15-150 8.006e-08 3.020e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 5.66317 (-5.65302 79.8526)
R1^2/D10^2 : 4.41517 (-4.41618 -4.41618)
kT2 [keV] : 13.5003 (-13.3922 -13.3922)
R2^2/D10^2 : 0.129368 (-0.134936 2.16826)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.22 using 59 PHA bins.
# Reduced chi-squared = 1.059 for 55 degrees of freedom
# Null hypothesis probability = 3.577965e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.223e-08 1.381e-08
25- 50 3.302e-08 1.899e-08
50-150 2.216e-08 1.575e-08
15-150 7.740e-08 4.566e-08
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: 1.94687 ( -0.126209 0.130131 )
Norm@50keV : 5.51967E-03 ( -0.000456849 0.000451029 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.58 using 59 PHA bins.
# Reduced chi-squared = 0.9049 for 57 degrees of freedom
# Null hypothesis probability = 6.779669e-01
Photon flux (15-150 keV) in 41.59 sec: 0.808367 ( -0.0579424 0.0580009 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.11241e-06 ( -1.6889e-07 1.70442e-07 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.20478 ( -0.593629 0.524016 )
Epeak [keV] : 47.7011 ( -9.61148 16.5618 )
Norm@50keV : 1.41396E-02 ( -0.00674837 0.0156579 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 45.44 using 59 PHA bins.
# Reduced chi-squared = 0.8115 for 56 degrees of freedom
# Null hypothesis probability = 8.423702e-01
Photon flux (15-150 keV) in 41.59 sec: 0.783388 ( -0.060346 0.060394 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.9899e-06 ( -1.84227e-07 1.88498e-07 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.21077 ( -0.517939 0.586609 )
beta : -9.36561 ( 9.3656 19.3656 )
Epeak [keV] : 47.7962 ( -8.70077 16.4366 )
Norm@50keV : 1.40176E-02 ( -0.00533964 0.00291279 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 45.44 using 59 PHA bins.
# Reduced chi-squared = 0.8262 for 55 degrees of freedom
# Null hypothesis probability = 8.174286e-01
Photon flux (15-150 keV) in 41.59 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 1.98702e-06 ( 0 0 ) ergs/cm2
S(25-50 keV) vs. S(50-100 keV) plot
S(25-50 keV) = 6.75e-07
S(50-100 keV) = 6.96e-07
T90 vs. Hardness ratio plot
T90 = 37.2479999661446 sec.
Hardness ratio (energy fluence ratio) = 1.03111
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.25076
Count Ratio (50-100 keV) / (15-25 keV) = 0.669185
Mask shadow pattern
IMX = -1.845495917877787E-01, IMY = -7.354137459376950E-01
TIME vs. PHA plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 64.000000
TIME vs. DetID plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 64.000000
100 us light curve (15-350 keV)
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 64.000000
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 35.112000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.5216 -40.5193 1.7 32.4 155.5 1.8294 6.9 2.1 Vela X-1
170.3025 -60.6752 3.8 33.8 -149.4 0.7206 3.1 3.2 Cen X-3
186.7515 -62.6763 4.7 38.5 -138.4 0.9454 2.4 6.2 GX 301-2
90.9357 -59.5056 2.0 3.6 51.2 1.1220 5.9 ------ UNKNOWN
74.4079 -64.3738 2.8 9.5 -22.0 0.7575 4.1 ------ UNKNOWN
162.2172 -85.8515 3.1 26.2 -99.7 1.0431 3.8 ------ UNKNOWN
205.2858 -54.5121 2.3 51.0 -135.6 5.1594 5.0 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
35.112000 76.700600
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.5125 -40.7092 3.7 32.2 155.7 0.2478 3.1 9.3 Vela X-1
170.3158 -60.6185 27.3 33.8 -149.4 0.0310 0.4 0.3 Cen X-3
186.5464 -62.6817 8.5 38.5 -138.5 -0.1360 -1.4 6.1 GX 301-2
105.3539 -25.8678 0.6 37.2 104.1 3.9706 21.0 ------ UNKNOWN
38.0890 -45.4418 2.4 36.1 -0.3 0.4239 4.9 ------ UNKNOWN
93.4180 -68.3165 2.6 5.9 -84.3 0.2717 4.5 ------ UNKNOWN
335.9878 -65.8560 2.5 44.3 -60.3 1.1685 4.7 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
134.300620 483.070600
661.000000 723.068900
841.000000 887.100590
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.5318 -40.5858 1.4 29.0 -124.0 3.0748 8.4 1.9 Vela X-1
86.1990 5.5592 3.8 36.5 74.7 2.1427 3.1 ------ UNKNOWN
52.5797 -11.7003 2.5 51.6 23.5 6.5050 4.5 ------ UNKNOWN
71.1410 -8.9346 2.3 36.6 39.3 2.2685 4.9 ------ UNKNOWN
101.9274 -30.5979 2.7 5.6 -40.2 1.1167 4.3 ------ UNKNOWN
105.9975 -64.2773 3.6 38.4 -72.5 2.5844 3.2 ------ UNKNOWN
123.1769 -65.2857 3.4 41.0 -83.3 4.6800 3.4 ------ UNKNOWN
Plot creation:
Sun May 31 11:08:41 EDT 2015