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
237.8987 -78.6530 0.0133 13.9036 47.3059 0.4054500 14.489 TRIG_00278903
Foreground time interval of the image:
-1.432 7.868 (delta_t = 9.300 [sec])
Background time interval of the image:
-239.248 -1.432 (delta_t = 237.816 [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 1.024000
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 1.024000
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 1.024000
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 -1.432 sec. to 7.868 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.20852 ( -0.217997 0.234555 )
Norm@50keV : 2.14152E-03 ( -0.000351314 0.000344452 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.85 using 59 PHA bins.
# Reduced chi-squared = 0.9623 for 57 degrees of freedom
# Null hypothesis probability = 5.561505e-01
Photon flux (15-150 keV) in 9.3 sec: 0.356131 ( -0.0387783 0.0387788 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.8748e-07 ( -2.58008e-08 2.66886e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.432 sec. to 7.868 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.86660 ( -1.13013 0.132192 )
Epeak [keV] : 14.4300 ( )
Norm@50keV : 3.50317E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.39 using 59 PHA bins.
# Reduced chi-squared = 0.9712 for 56 degrees of freedom
# Null hypothesis probability = 5.361380e-01
Photon flux (15-150 keV) in 9.3 sec: 0.351637 ( -0.040119 0.040219 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.79005e-07 ( -3.16526e-08 3.27899e-08 ) ergs/cm2
Band function
Time interval is from -1.432 sec. to 7.868 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.91189 ( 1.94648 1.94648 )
beta : -10.0000 ( 10 20 )
Epeak [keV] : 11.0766 ( -7.07769 26.0377 )
Norm@50keV : 3.27528E-03 ( -0.000939823 0.0154743 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.40 using 59 PHA bins.
# Reduced chi-squared = 0.9890 for 55 degrees of freedom
# Null hypothesis probability = 4.976767e-01
Photon flux (15-150 keV) in 9.3 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] : 7.68655 (-0.940489 1.08706)
R^2/D10^2 : 0.453608 (-0.18762 0.31807)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 67.86 using 59 PHA bins.
# Reduced chi-squared = 1.191 for 57 degrees of freedom
# Null hypothesis probability = 1.537110e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.368e-08 7.445e-09
25- 50 7.124e-08 1.124e-08
50-150 1.637e-08 6.390e-09
15-150 1.313e-07 1.930e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 44.0500 (-11.9275 19.3108)
Norm : 2.16181 (-0.417477 0.570181)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.10 using 59 PHA bins.
# Reduced chi-squared = 0.9666 for 57 degrees of freedom
# Null hypothesis probability = 5.468259e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.758e-08 6.482e-09
25- 50 6.515e-08 8.012e-09
50-150 5.583e-08 2.038e-08
15-150 1.686e-07 2.692e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 5.83733 (-1.2743 1.24361)
R1^2/D10^2 : 1.14962 (-0.593498 1.71919)
kT2 [keV] : 23.4934 (-9.3714 26.8193)
R2^2/D10^2 : 3.47029E-03 (-0.00314777 0.022424)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.12 using 59 PHA bins.
# Reduced chi-squared = 0.9477 for 55 degrees of freedom
# Null hypothesis probability = 5.852049e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.968e-08 1.605e-08
25- 50 6.117e-08 2.180e-08
50-150 7.580e-08 4.590e-08
15-150 1.867e-07 7.588e-08
Peak spectrum fit
Power-law model
Time interval is from -0.308 sec. to 0.692 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.59257 ( -0.280953 0.290974 )
Norm@50keV : 5.27581E-03 ( -0.00097606 0.000960949 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 65.41 using 59 PHA bins.
# Reduced chi-squared = 1.147 for 57 degrees of freedom
# Null hypothesis probability = 2.079802e-01
Photon flux (15-150 keV) in 1 sec: 0.676414 ( -0.116489 0.116594 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.93855e-08 ( -9.68154e-09 9.90873e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.308 sec. to 0.692 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.179318 ( -1.85084 1.27755 )
Epeak [keV] : 61.1717 ( -14.7376 109.498 )
Norm@50keV : 2.89881E-02 ( -0.0289881 0.230616 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.74 using 59 PHA bins.
# Reduced chi-squared = 1.103 for 56 degrees of freedom
# Null hypothesis probability = 2.784117e-01
Photon flux (15-150 keV) in 1 sec: 0.642879 ( -0.121519 0.120909 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.47917e-08 ( -9.7883e-09 1.05818e-08 ) ergs/cm2
Band function
Time interval is from -0.308 sec. to 0.692 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.179099 ( -0.721924 2.73844 )
beta : -10.0000 ( 10 0 )
Epeak [keV] : 61.1555 ( -14.7323 109.861 )
Norm@50keV : 2.90004E-02 ( -0.0290003 0.231635 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.74 using 59 PHA bins.
# Reduced chi-squared = 1.123 for 55 degrees of freedom
# Null hypothesis probability = 2.478474e-01
Photon flux (15-150 keV) in 1 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] : 13.7420 (-2.32493 2.93268)
R^2/D10^2 : 0.108065 (-0.054386 0.102493)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 64.01 using 59 PHA bins.
# Reduced chi-squared = 1.123 for 57 degrees of freedom
# Null hypothesis probability = 2.440095e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.318e-09 1.422e-09
25- 50 1.576e-08 4.531e-09
50-150 1.941e-08 6.735e-09
15-150 3.949e-08 1.016e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 163.741 (-83.7713 -161.577)
Norm : 2.80347 (-0.495807 0.652647)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.68 using 59 PHA bins.
# Reduced chi-squared = 1.117 for 57 degrees of freedom
# Null hypothesis probability = 2.530369e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.142e-09 3.964e-09
25- 50 1.340e-08 7.335e-09
50-150 2.740e-08 1.592e-08
15-150 4.794e-08 2.698e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 2.87394 (-2.03299 10.0894)
R1^2/D10^2 : 19.7745 (-19.3465 210.814)
kT2 [keV] : 15.3357 (-2.9974 30.8719)
R2^2/D10^2 : 6.88596E-02 (-0.0682837 0.0310519)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.80 using 59 PHA bins.
# Reduced chi-squared = 1.106 for 55 degrees of freedom
# Null hypothesis probability = 2.748519e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 6.195e-09 3.179e-09
25- 50 1.405e-08 6.226e-09
50-150 2.213e-08 1.176e-08
15-150 4.237e-08 1.858e-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: 2.20852 ( -0.217997 0.234555 )
Norm@50keV : 2.14152E-03 ( -0.000351314 0.000344452 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.85 using 59 PHA bins.
# Reduced chi-squared = 0.9623 for 57 degrees of freedom
# Null hypothesis probability = 5.561505e-01
Photon flux (15-150 keV) in 9.3 sec: 0.356131 ( -0.0387783 0.0387788 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.8748e-07 ( -2.58008e-08 2.66886e-08 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.86660 ( -1.13013 0.132192 )
Epeak [keV] : 14.4300 ( )
Norm@50keV : 3.50317E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.39 using 59 PHA bins.
# Reduced chi-squared = 0.9712 for 56 degrees of freedom
# Null hypothesis probability = 5.361380e-01
Photon flux (15-150 keV) in 9.3 sec: 0.351637 ( -0.040119 0.040219 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.79005e-07 ( -3.16526e-08 3.27899e-08 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.91189 ( 1.94648 1.94648 )
beta : -10.0000 ( 10 20 )
Epeak [keV] : 11.0766 ( -7.07778 26.0407 )
Norm@50keV : 3.27528E-03 ( -0.000939823 0.0154743 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.40 using 59 PHA bins.
# Reduced chi-squared = 0.9890 for 55 degrees of freedom
# Null hypothesis probability = 4.976767e-01
Photon flux (15-150 keV) in 9.3 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) = 5.95e-08
S(50-100 keV) = 5.15e-08
T90 vs. Hardness ratio plot
T90 = 7.82800000905991 sec.
Hardness ratio (energy fluence ratio) = 0.865546
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 0.89451
Count Ratio (50-100 keV) / (15-25 keV) = 0.355856
Mask shadow pattern
IMX = 1.678535513484074E-01, IMY = -1.819385232035663E-01
TIME vs. PHA plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 1.024000
TIME vs. DetID plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 1.024000
100 us light curve (15-350 keV)
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 1.024000
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:
-239.248000 -1.432000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
170.3734 -60.6387 29.7 39.1 23.3 0.1095 0.4 1.9 Cen X-3
186.7613 -62.7889 3.1 35.2 34.9 0.9350 3.7 3.1 GX 301-2
264.9704 -44.5019 154.1 38.5 116.8 0.0336 0.1 10.2 4U 1735-44
280.5538 -34.9891 2.3 45.5 137.2 2.9659 5.0 ------ UNKNOWN
329.8789 -19.9327 2.8 59.0 -166.2 4.5616 4.2 ------ UNKNOWN
85.8220 -47.7589 2.5 50.7 -44.4 4.2694 4.5 ------ UNKNOWN
13.3308 -41.8079 2.8 43.4 -114.1 3.2197 4.0 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-1.432000 7.868000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
170.2062 -60.7490 3.7 39.1 23.1 -0.1514 -3.1 8.2 Cen X-3
186.6087 -62.6739 6.2 35.3 34.9 0.0880 1.9 5.9 GX 301-2
264.6636 -44.5018 9.7 38.5 116.5 0.1013 1.2 4.6 4U 1735-44
252.5674 -53.5192 2.6 32.1 98.9 0.2199 4.4 ------ UNKNOWN
299.8430 -26.0391 2.4 52.7 160.4 0.5969 4.7 ------ UNKNOWN
237.8987 -78.6530 0.8 13.9 47.3 0.4054 14.5 ------ UNKNOWN
327.1704 -20.8920 2.3 57.9 -169.1 0.7215 5.1 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
52.252600 962.834000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.6268 -40.3915 5.0 52.9 -7.7 -2.9523 -2.3 10.8 Vela X-1
170.2972 -60.6246 2.6 27.0 14.9 2.1897 4.3 0.6 Cen X-3
186.6806 -62.7816 1.0 21.8 29.9 5.6952 11.9 0.9 GX 301-2
256.0483 -37.7072 63.7 41.7 125.1 0.3146 0.2 8.7 4U 1700-377
256.4087 -36.3451 4.1 43.0 125.3 5.6784 2.8 4.8 GX 349+2
264.7283 -44.4617 41.4 35.7 136.8 0.2617 0.3 0.9 4U 1735-44
275.9226 -30.4950 26.3 50.9 146.5 1.1221 0.4 7.7 H1820-303
263.0346 -33.9111 4.2 46.0 132.6 5.5466 2.8 5.1 GX 354-0
Plot creation:
Sun May 31 10:17:03 EDT 2015