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
20.7699 -64.0522 0.0152 9.6990 -170.7357 1.1207534 12.706 TRIG_00312242
Foreground time interval of the image:
-15.112 32.888 (delta_t = 48.000 [sec])
Background time interval of the image:
-48.211 -15.112 (delta_t = 33.099 [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 3.072000
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 3.072000
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 3.072000
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 -15.112 sec. to 32.888 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.27131 ( -0.136371 0.135697 )
Norm@50keV : 1.60604E-03 ( -0.000128972 0.000128897 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 77.39 using 59 PHA bins.
# Reduced chi-squared = 1.358 for 57 degrees of freedom
# Null hypothesis probability = 3.744407e-02
Photon flux (15-150 keV) in 48 sec: 0.190629 ( -0.015539 0.0155572 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.67266e-07 ( -6.89213e-08 6.9468e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -15.112 sec. to 32.888 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.430540 ( -0.680253 0.584062 )
Epeak [keV] : 97.6302 ( -22.7582 97.3806 )
Norm@50keV : 4.09382E-03 ( -0.0019186 0.00435507 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 71.00 using 59 PHA bins.
# Reduced chi-squared = 1.268 for 56 degrees of freedom
# Null hypothesis probability = 8.547481e-02
Photon flux (15-150 keV) in 48 sec: 0.183588 ( -0.016393 0.016305 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.23878e-07 ( -7.524e-08 7.59456e-08 ) ergs/cm2
Band function
Time interval is from -15.112 sec. to 32.888 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.430456 ( -0.502322 0.758813 )
beta : -10.0000 ( 10 3.55271e-15 )
Epeak [keV] : 97.6098 ( -29.3116 97.2527 )
Norm@50keV : 4.09432E-03 ( -0.00191962 0.00435722 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 71.00 using 59 PHA bins.
# Reduced chi-squared = 1.291 for 55 degrees of freedom
# Null hypothesis probability = 7.205617e-02
Photon flux (15-150 keV) in 48 sec: 0.184408 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 7.23586e-07 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 17.5865 (-1.62918 1.84206)
R^2/D10^2 : 1.34173E-02 (-0.00382322 0.00521238)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 86.09 using 59 PHA bins.
# Reduced chi-squared = 1.510 for 57 degrees of freedom
# Null hypothesis probability = 7.677213e-03
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.017e-08 6.108e-09
25- 50 1.825e-07 1.963e-08
50-150 4.072e-07 5.844e-08
15-150 6.299e-07 7.344e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 ( )
Norm : 0.787499 (-0.0635687 0.063565)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 85.21 using 59 PHA bins.
# Reduced chi-squared = 1.495 for 57 degrees of freedom
# Null hypothesis probability = 9.127266e-03
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 9.411e-08 9.336e-09
25- 50 1.810e-07 4.207e-08
50-150 3.971e-07 1.434e-07
15-150 6.722e-07 1.652e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 5.37595 (-1.71231 2.88434)
R1^2/D10^2 : 0.303157 (-0.232232 1.18734)
kT2 [keV] : 21.4781 (-2.8639 4.78684)
R2^2/D10^2 : 6.19957E-03 (-0.00332275 0.00234293)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 69.27 using 59 PHA bins.
# Reduced chi-squared = 1.259 for 55 degrees of freedom
# Null hypothesis probability = 9.334015e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.257e-08 3.184e-08
25- 50 1.703e-07 4.927e-08
50-150 4.630e-07 1.158e-07
15-150 7.059e-07 1.722e-07
Peak spectrum fit
Power-law model
Time interval is from 8.388 sec. to 9.388 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.50087 ( -0.555485 0.58848 )
Norm@50keV : 2.26310E-03 ( -0.000902655 0.000889662 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 65.63 using 59 PHA bins.
# Reduced chi-squared = 1.151 for 57 degrees of freedom
# Null hypothesis probability = 2.024582e-01
Photon flux (15-150 keV) in 1 sec: 0.282589 ( -0.10558 0.105687 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.14668e-08 ( -8.94111e-09 9.52152e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 8.388 sec. to 9.388 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.55998 ( 1.61816 2.91635 )
Epeak [keV] : 48.2861 ( -15.294 95.247 )
Norm@50keV : 0.129504 ( -0.162079 82314.2 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.12 using 59 PHA bins.
# Reduced chi-squared = 1.109 for 56 degrees of freedom
# Null hypothesis probability = 2.673290e-01
Photon flux (15-150 keV) in 1 sec: 0.259480 ( -0.101333 0.108376 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.58957e-08 ( -6.94256e-09 1.0997e-08 ) ergs/cm2
Band function
Time interval is from 8.388 sec. to 9.388 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.95572 ( -5.59019 -4.95572 )
beta : -2.64514 ( 2.64514 1.15396 )
Epeak [keV] : 36.9226 ( -12.1111 13.3759 )
Norm@50keV : 27.9073 ( -9.42325 278.06 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.29 using 59 PHA bins.
# Reduced chi-squared = 1.114 for 55 degrees of freedom
# Null hypothesis probability = 2.607480e-01
Photon flux (15-150 keV) in 1 sec: 0.265711 ( 6.73429 -0.096017 ) 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] : 12.3440 (-3.60246 6.18403)
R^2/D10^2 : 7.11258E-02 (-0.0711268 0.173166)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.23 using 59 PHA bins.
# Reduced chi-squared = 1.092 for 57 degrees of freedom
# Null hypothesis probability = 2.955138e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.297e-09 1.426e-09
25- 50 7.468e-09 4.534e-09
50-150 6.970e-09 4.793e-09
15-150 1.673e-08 1.061e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 159.626 (-158.759 -158.759)
Norm : 1.19387 (-0.443387 0.60397)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.75 using 59 PHA bins.
# Reduced chi-squared = 1.136 for 57 degrees of freedom
# Null hypothesis probability = 2.245595e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.049e-09 1.914e-09
25- 50 5.702e-09 3.540e-09
50-150 1.154e-08 7.545e-09
15-150 2.029e-08 1.286e-08
Double BB
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 10.1240 (-9.61918 -9.61918)
R1^2/D10^2 : 9.40251E-02 (-0.0288375 -0.0288375)
kT2 [keV] : 18.2179 (-13.1745 -13.1745)
R2^2/D10^2 : 6.55532E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.22 using 59 PHA bins.
#Fit statistic : Chi-Squared = 62.12 using 59 PHA bins.
# Reduced chi-squared = 1.131 for 55 degrees of freedom
# Reduced chi-squared = 1.129 for 55 degrees of freedom
# Null hypothesis probability = 2.347674e-01
# Null hypothesis probability = 2.374718e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.320e-09 4.044e-06
25- 50 7.458e-09 3.565e-05
50-150 7.010e-09 8.175e-04
15-150 1.679e-08 8.565e-04
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: 1.27131 ( -0.136371 0.135697 )
Norm@50keV : 1.60604E-03 ( -0.000128972 0.000128897 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 77.39 using 59 PHA bins.
# Reduced chi-squared = 1.358 for 57 degrees of freedom
# Null hypothesis probability = 3.744407e-02
Photon flux (15-150 keV) in 48 sec: 0.190629 ( -0.015539 0.0155572 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.67266e-07 ( -6.89213e-08 6.9468e-08 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.430540 ( -0.680253 0.584062 )
Epeak [keV] : 97.6302 ( -22.7582 97.3806 )
Norm@50keV : 4.09382E-03 ( -0.0019186 0.00435507 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 71.00 using 59 PHA bins.
# Reduced chi-squared = 1.268 for 56 degrees of freedom
# Null hypothesis probability = 8.547481e-02
Photon flux (15-150 keV) in 48 sec: 0.183588 ( -0.016393 0.016305 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.23878e-07 ( -7.524e-08 7.59456e-08 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.430456 ( -0.502322 0.758813 )
beta : -10.0000 ( 10 1.79412e-13 )
Epeak [keV] : 97.6098 ( -29.3116 97.2527 )
Norm@50keV : 4.09432E-03 ( -0.00191962 0.00435722 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 71.00 using 59 PHA bins.
# Reduced chi-squared = 1.291 for 55 degrees of freedom
# Null hypothesis probability = 7.205617e-02
Photon flux (15-150 keV) in 48 sec: 0.184408 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 7.23586e-07 ( 0 0 ) ergs/cm2
S(25-50 keV) vs. S(50-100 keV) plot
S(25-50 keV) = 1.68e-07
S(50-100 keV) = 2.78e-07
T90 vs. Hardness ratio plot
T90 = 48 sec.
Hardness ratio (energy fluence ratio) = 1.65476
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.461
Count Ratio (50-100 keV) / (15-25 keV) = 1.46339
Mask shadow pattern
IMX = -1.686856964636226E-01, IMY = 2.751554163584609E-02
TIME vs. PHA plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 3.072000
TIME vs. DetID plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 3.072000
100 us light curve (15-350 keV)
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 3.072000
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:
-48.211400 -15.112000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.4254 -40.5100 8.2 54.3 -8.6 -0.2267 -1.4 5.4 Vela X-1
170.4940 -60.7613 622.4 43.9 28.3 0.0020 0.0 9.8 Cen X-3
186.5520 -62.7620 12.7 44.2 39.6 -0.1401 -0.9 2.9 GX 301-2
348.0501 -55.2273 2.5 26.4 160.5 0.2534 4.6 ------ UNKNOWN
125.3244 -39.0884 2.1 52.5 -18.2 0.7716 5.4 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-15.112000 32.888000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.6316 -40.5996 12.7 54.3 -8.4 0.2645 0.9 5.4 Vela X-1
170.0896 -60.4829 6.3 44.1 27.9 0.4033 1.8 10.7 Cen X-3
186.6909 -62.7197 5.5 44.2 39.6 0.5909 2.1 3.2 GX 301-2
325.1862 -59.5077 2.5 30.2 134.1 0.6522 4.5 ------ UNKNOWN
20.7699 -64.0523 0.9 9.7 -170.7 1.1208 12.7 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
75.188590 867.388600
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
147.2066 -60.7112 2.4 48.9 21.5 4.2140 4.8 ------ UNKNOWN
12.7315 -38.1788 2.8 26.3 -141.4 1.1401 4.2 ------ UNKNOWN
35.9570 -39.4125 2.7 26.2 -99.7 1.6897 4.4 ------ UNKNOWN
2.7016 -16.3717 3.0 49.3 -150.1 2.6201 3.9 ------ UNKNOWN
Plot creation:
Mon Jun 22 17:07:33 EDT 2015