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
147.5182 -42.3315 0.0189 34.1083 39.1001 1.1217662 10.133 TRIG_00548276
Foreground time interval of the image:
-3.404 32.312 (delta_t = 35.716 [sec])
Background time interval of the image:
-239.368 -3.404 (delta_t = 235.964 [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 8.192000
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 8.192000
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 8.192000
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)
The mask-weighted light curves based on cleaned DPHs
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 -3.404 sec. to 32.312 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.85273 ( -0.243409 0.255446 )
Norm@50keV : 1.98432E-03 ( -0.000319047 0.000310529 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.91 using 59 PHA bins.
# Reduced chi-squared = 1.086 for 57 degrees of freedom
# Null hypothesis probability = 3.051781e-01
Photon flux (15-150 keV) in 35.72 sec: 0.279226 ( -0.0382962 0.0383228 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.51704e-07 ( -1.03128e-07 1.0512e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -3.404 sec. to 32.312 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.69212 ( -0.975154 0.617822 )
Epeak [keV] : 84.7419 ( -84.7195 -84.7409 )
Norm@50keV : 2.44182E-03 ( -0.0024419 0.00615125 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.80 using 59 PHA bins.
# Reduced chi-squared = 1.104 for 56 degrees of freedom
# Null hypothesis probability = 2.766341e-01
Photon flux (15-150 keV) in 35.72 sec: 0.277598 ( -0.039125 0.039092 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.41985e-07 ( -1.15451e-07 1.12343e-07 ) ergs/cm2
Band function
Time interval is from -3.404 sec. to 32.312 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.69159 ( -1.88271 0.976414 )
beta : -10.00000 ( 10 20 )
Epeak [keV] : 84.5992 ( -64.8234 -84.5992 )
Norm@50keV : 2.44293E-03 ( -0.000331738 0.00614475 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.80 using 59 PHA bins.
# Reduced chi-squared = 1.124 for 55 degrees of freedom
# Null hypothesis probability = 2.461835e-01
Photon flux (15-150 keV) in 35.72 sec: 0.276522 ( ) 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] : 10.0939 (-1.67122 2.17989)
R^2/D10^2 : 0.124449 (-0.124072 0.124554)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 77.14 using 59 PHA bins.
# Reduced chi-squared = 1.353 for 57 degrees of freedom
# Null hypothesis probability = 3.905770e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 9.253e-08 2.329e-08
25- 50 2.331e-07 4.944e-08
50-150 1.250e-07 4.613e-08
15-150 4.506e-07 8.330e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 90.7401 (-34.5502 82.0101)
Norm : 1.26110 (-0.234648 0.311977)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 62.30 using 59 PHA bins.
# Reduced chi-squared = 1.093 for 57 degrees of freedom
# Null hypothesis probability = 2.933605e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.176e-07 2.300e-08
25- 50 1.992e-07 3.490e-08
50-150 3.049e-07 1.581e-07
15-150 6.216e-07 1.904e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 6.72477 (-1.66312 1.77879)
R1^2/D10^2 : 0.459382 (-0.267704 0.466036)
kT2 [keV] : 29.0643 (-10.2906 29.9335)
R2^2/D10^2 : 1.82256E-03 (-0.00161677 0.00731299)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.62 using 59 PHA bins.
# Reduced chi-squared = 1.084 for 55 degrees of freedom
# Null hypothesis probability = 3.113543e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.229e-07 6.457e-08
25- 50 1.978e-07 9.297e-08
50-150 3.430e-07 1.858e-07
15-150 6.637e-07 3.426e-07
Peak spectrum fit
Power-law model
Time interval is from -1.580 sec. to -0.580 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.55388 ( -0.465746 0.492169 )
Norm@50keV : 5.96080E-03 ( -0.0017918 0.00176072 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 69.77 using 59 PHA bins.
# Reduced chi-squared = 1.224 for 57 degrees of freedom
# Null hypothesis probability = 1.193639e-01
Photon flux (15-150 keV) in 1 sec: 0.755455 ( -0.220842 0.221676 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.60846e-08 ( -1.76778e-08 1.80722e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.580 sec. to -0.580 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.239530 ( -3.68771 1.6631 )
Epeak [keV] : 69.2657 ( -23.5319 -69.2666 )
Norm@50keV : 2.63175E-02 ( -0.0263167 1.64462 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 68.52 using 59 PHA bins.
# Reduced chi-squared = 1.223 for 56 degrees of freedom
# Null hypothesis probability = 1.217200e-01
Photon flux (15-150 keV) in 1 sec: 0.720802 ( -0.231041 0.229335 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.30274e-08 ( -1.8038e-08 1.87765e-08 ) ergs/cm2
Band function
Time interval is from -1.580 sec. to -0.580 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.239249 ( -0.99155 0.917161 )
beta : -10.0000 ( 10 20 )
Epeak [keV] : 69.2335 ( -25.534 248.495 )
Norm@50keV : 2.63355E-02 ( -0.0263355 1.65625 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 68.52 using 59 PHA bins.
# Reduced chi-squared = 1.246 for 55 degrees of freedom
# Null hypothesis probability = 1.041090e-01
Photon flux (15-150 keV) in 1 sec: 0.737701 ( 6.2623 -0.24768 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.6639e-08 ( -5.6632e-08 -2.27596e-08 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 15.2019 (-4.17595 6.0619)
R^2/D10^2 : 8.57936E-02 (-0.0857847 0.180505)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 69.48 using 59 PHA bins.
# Reduced chi-squared = 1.219 for 57 degrees of freedom
# Null hypothesis probability = 1.241720e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.142e-09 2.528e-09
25- 50 1.666e-08 9.813e-09
50-150 2.635e-08 1.651e-08
15-150 4.715e-08 2.828e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 186.000 (-122.069 -185.446)
Norm : 3.12536 (-0.899337 1.19669)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 69.20 using 59 PHA bins.
# Reduced chi-squared = 1.214 for 57 degrees of freedom
# Null hypothesis probability = 1.289995e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.851e-09 4.666e-09
25- 50 1.498e-08 9.065e-09
50-150 3.208e-08 1.903e-08
15-150 5.491e-08 3.316e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 2.64666 (-2.6196 22.107)
R1^2/D10^2 : 41.8584 (-50.2743 -50.2743)
kT2 [keV] : 16.8272 (-4.94395 -16.8368)
R2^2/D10^2 : 5.66562E-02 (-0.057547 0.141016)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 67.75 using 59 PHA bins.
# Reduced chi-squared = 1.232 for 55 degrees of freedom
# Null hypothesis probability = 1.160428e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 6.716e-09 4.673e-09
25- 50 1.469e-08 8.955e-09
50-150 2.897e-08 1.875e-08
15-150 5.038e-08 3.008e-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: 1.85273 ( -0.243409 0.255446 )
Norm@50keV : 1.98432E-03 ( -0.000319047 0.000310529 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.91 using 59 PHA bins.
# Reduced chi-squared = 1.086 for 57 degrees of freedom
# Null hypothesis probability = 3.051781e-01
Photon flux (15-150 keV) in 35.72 sec: 0.279226 ( -0.0382962 0.0383228 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.51704e-07 ( -1.03128e-07 1.0512e-07 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.69212 ( -0.975154 0.617964 )
Epeak [keV] : 84.7419 ( -84.7195 -84.7409 )
Norm@50keV : 2.44182E-03 ( -0.0024419 0.00615125 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.80 using 59 PHA bins.
# Reduced chi-squared = 1.104 for 56 degrees of freedom
# Null hypothesis probability = 2.766341e-01
Photon flux (15-150 keV) in 35.72 sec: 0.277598 ( -0.039125 0.039092 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.41985e-07 ( -1.15451e-07 1.12343e-07 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.69159 ( -1.88271 0.976414 )
beta : -10.00000 ( 10 20 )
Epeak [keV] : 84.5992 ( -64.8234 -84.5992 )
Norm@50keV : 2.44293E-03 ( -0.000331738 0.00614475 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.80 using 59 PHA bins.
# Reduced chi-squared = 1.124 for 55 degrees of freedom
# Null hypothesis probability = 2.461835e-01
Photon flux (15-150 keV) in 35.72 sec: 0.276522 ( ) 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) = 1.87e-07
S(50-100 keV) = 2.07e-07
T90 vs. Hardness ratio plot
T90 = 30.7519999146461 sec.
Hardness ratio (energy fluence ratio) = 1.10695
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.12678
Count Ratio (50-100 keV) / (15-25 keV) = 0.567708
Mask shadow pattern
IMX = 5.255861683523052E-01, IMY = -4.271340771280909E-01
TIME vs. PHA plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 8.192000
TIME vs. DetID plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 8.192000
100 us light curve (15-350 keV)
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 8.192000
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:
-239.368000 -3.404000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.4586 -40.4910 3.0 42.8 34.1 1.5952 3.8 5.0 Vela X-1
170.2822 -60.6238 1.0 18.5 -1.0 1.9366 11.6 1.0 Cen X-3
186.6555 -62.5882 8.5 14.2 -25.4 0.2421 1.4 10.9 GX 301-2
244.9694 -15.6426 0.7 51.8 -157.1 8.4822 16.3 0.6 Sco X-1
256.1038 -37.8041 8.1 43.6 -125.9 -0.8284 -1.4 6.1 4U 1700-377
256.4443 -36.4238 112.3 44.6 -127.3 0.0624 0.1 0.4 GX 349+2
184.3435 -14.3026 2.7 36.5 116.2 1.8993 4.3 ------ UNKNOWN
197.0856 -13.5923 2.0 35.9 137.3 1.8929 5.6 ------ UNKNOWN
135.4406 -50.6938 3.0 38.0 20.2 1.0212 3.9 ------ UNKNOWN
150.6217 -49.2085 3.2 29.3 28.8 0.8085 3.6 ------ UNKNOWN
152.9373 -82.4213 2.6 35.4 -34.9 1.0714 4.4 ------ UNKNOWN
54.4135 -70.5819 2.6 56.9 -29.8 4.7886 4.4 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-3.404000 32.312000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.7005 -40.5576 2.7 42.6 34.2 0.6473 4.2 7.8 Vela X-1
170.7014 -60.6750 7.6 18.3 -1.4 0.0924 1.5 11.8 Cen X-3
186.4241 -62.7042 6.5 14.3 -25.3 0.1025 1.8 7.5 GX 301-2
244.9822 -15.6377 67.6 51.8 -157.0 0.0287 0.2 0.2 Sco X-1
255.9612 -37.7143 14.4 43.5 -126.1 -0.1482 -0.8 7.9 4U 1700-377
256.5894 -36.3316 4.9 44.7 -127.3 0.4903 2.3 9.2 GX 349+2
147.5182 -42.3315 1.1 34.1 39.1 1.1218 10.1 ------ UNKNOWN
224.9184 -0.0585 2.3 55.1 171.7 1.6494 5.1 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
102.932620 463.532600
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
135.5040 -40.5747 0.9 9.2 10.3 2.7519 12.8 1.6 Vela X-1
170.3347 -60.6406 1.1 22.9 -116.0 2.9030 10.7 1.2 Cen X-3
186.6230 -62.6647 4.6 30.5 -121.6 0.8067 2.5 6.4 GX 301-2
150.5628 -16.3673 3.1 26.1 99.9 1.4150 3.7 ------ UNKNOWN
66.3653 -58.1219 3.4 50.8 -44.5 4.6415 3.4 ------ UNKNOWN
117.8731 -82.2195 2.3 41.0 -80.9 5.0554 5.1 ------ UNKNOWN
72.6462 -68.7927 3.2 45.7 -57.6 4.4650 3.6 ------ UNKNOWN
Plot creation:
Sat May 30 17:25:39 EDT 2015