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
280.1939 -54.9656 0.0209 17.3684 -157.9874 0.1762445 9.260 TRIG_00312047
Foreground time interval of the image:
-0.312 3.324 (delta_t = 3.636 [sec])
Background time interval of the image:
-137.283 -0.312 (delta_t = 136.971 [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 2.048000
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 2.048000
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 2.048000
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 -0.312 sec. to 3.324 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 3.08025 ( -0.462925 0.576709 )
Norm@50keV : 1.29706E-03 ( -0.000546091 0.000603509 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.79 using 59 PHA bins.
# Reduced chi-squared = 0.9787 for 57 degrees of freedom
# Null hypothesis probability = 5.206201e-01
Photon flux (15-150 keV) in 3.636 sec: 0.378363 ( -0.0688647 0.0690302 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.88588e-08 ( -1.37038e-08 1.49732e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.312 sec. to 3.324 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.89773 ( )
Epeak [keV] : 2.66527 ( )
Norm@50keV : 8.42231E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.34 using 59 PHA bins.
# Reduced chi-squared = 0.9883 for 56 degrees of freedom
# Null hypothesis probability = 4.996999e-01
Photon flux (15-150 keV) in 3.636 sec: 0.374687 ( -0.067764 0.068812 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.59322e-08 ( -1.2778e-08 1.62449e-08 ) ergs/cm2
Band function
Time interval is from -0.312 sec. to 3.324 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.94143 ( -4.16157 1.91072 )
beta : -9.37167 ( 9.37167 19.3716 )
Epeak [keV] : 1.59157 ( -1.59154 19.0538 )
Norm@50keV : 7.83205E-03 ( -0.00324598 0.00761842 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.32 using 59 PHA bins.
# Reduced chi-squared = 1.006 for 55 degrees of freedom
# Null hypothesis probability = 4.624301e-01
Photon flux (15-150 keV) in 3.636 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] : 5.32419 (-1.24209 1.50642)
R^2/D10^2 : 2.31979 (-1.54245 5.81706)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.84 using 59 PHA bins.
# Reduced chi-squared = 1.067 for 57 degrees of freedom
# Null hypothesis probability = 3.395073e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.620e-08 1.040e-08
25- 50 1.992e-08 8.819e-09
50-150 1.088e-09 8.109e-10
15-150 4.721e-08 1.821e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 18.1797 (-6.36723 9.81793)
Norm : 5.16312 (-2.04412 4.11706)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.75 using 59 PHA bins.
# Reduced chi-squared = 0.9781 for 57 degrees of freedom
# Null hypothesis probability = 5.220847e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.673e-08 7.468e-09
25- 50 2.168e-08 7.414e-09
50-150 5.505e-09 4.117e-09
15-150 5.392e-08 1.533e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 2.73584 (-1.22522 1.57537)
R1^2/D10^2 : 44.9997 (-42.9126 3854.03)
kT2 [keV] : 8.77731 (-2.68764 4.92842)
R2^2/D10^2 : 0.184049 (-0.169562 0.905869)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.82 using 59 PHA bins.
# Reduced chi-squared = 0.9785 for 55 degrees of freedom
# Null hypothesis probability = 5.198369e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.676e-08 1.366e-08
25- 50 2.199e-08 1.240e-08
50-150 7.145e-09 4.549e-09
15-150 5.590e-08 2.843e-08
Peak spectrum fit
Power-law model
Time interval is from 0.020 sec. to 1.020 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.58555 ( -0.549233 0.724471 )
Norm@50keV : 2.35728E-03 ( -0.00114645 0.00116333 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.94 using 59 PHA bins.
# Reduced chi-squared = 0.7885 for 57 degrees of freedom
# Null hypothesis probability = 8.763171e-01
Photon flux (15-150 keV) in 1 sec: 0.488453 ( -0.129506 0.12972 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.41564e-08 ( -8.12353e-09 8.97275e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.020 sec. to 1.020 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.58268 ( )
Epeak [keV] : 14.6289 ( )
Norm@50keV : 1.04210E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.48 using 59 PHA bins.
# Reduced chi-squared = 0.7942 for 56 degrees of freedom
# Null hypothesis probability = 8.664363e-01
Photon flux (15-150 keV) in 1 sec: 0.481366 ( -0.125686 0.129327 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.25019e-08 ( -7.2535e-09 9.7918e-09 ) ergs/cm2
Band function
Time interval is from 0.020 sec. to 1.020 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.73507 ( -4.73507 -4.73507 )
beta : -2.65610 ( -0.947952 0.597053 )
Epeak [keV] : 16.9474 ( -16.9474 6.95503 )
Norm@50keV : 5614.79 ( -1471.58 1.58522e+07 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.83 using 59 PHA bins.
# Reduced chi-squared = 0.8152 for 55 degrees of freedom
# Null hypothesis probability = 8.344338e-01
Photon flux (15-150 keV) in 1 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 2.39807e-08 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 7.83341 (-2.43934 2.59377)
R^2/D10^2 : 0.591759 (-0.590678 2.12753)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.21 using 59 PHA bins.
# Reduced chi-squared = 0.8283 for 57 degrees of freedom
# Null hypothesis probability = 8.189851e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 6.461e-09 3.886e-09
25- 50 1.090e-08 6.445e-09
50-150 2.669e-09 2.069e-09
15-150 2.003e-08 1.080e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 29.6096 (-13.6659 30.1785)
Norm : 4.01575 (-1.71712 3.692)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.52 using 59 PHA bins.
# Reduced chi-squared = 0.7810 for 57 degrees of freedom
# Null hypothesis probability = 8.855963e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 8.118e-09 3.465e-09
25- 50 9.209e-09 4.463e-09
50-150 4.957e-09 4.124e-09
15-150 2.228e-08 1.157e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 2.73196 (-1.63703 2.41023)
R1^2/D10^2 : 45.3646 (-49.1995 127911)
kT2 [keV] : 10.2994 (-3.05648 5.11433)
R2^2/D10^2 : 0.155911 (-0.137694 0.482413)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 42.66 using 59 PHA bins.
# Reduced chi-squared = 0.7757 for 55 degrees of freedom
# Null hypothesis probability = 8.874211e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 8.029e-09 4.006e-09
25- 50 9.289e-09 5.595e-09
50-150 5.004e-09 3.447e-09
15-150 2.232e-08 1.148e-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: 3.08025 ( -0.462925 0.576709 )
Norm@50keV : 1.29706E-03 ( -0.000546091 0.000603509 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.79 using 59 PHA bins.
# Reduced chi-squared = 0.9787 for 57 degrees of freedom
# Null hypothesis probability = 5.206201e-01
Photon flux (15-150 keV) in 3.636 sec: 0.378363 ( -0.0688647 0.0690302 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.88588e-08 ( -1.37038e-08 1.49732e-08 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.89773 ( )
Epeak [keV] : 2.66527 ( )
Norm@50keV : 8.42231E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.34 using 59 PHA bins.
# Reduced chi-squared = 0.9883 for 56 degrees of freedom
# Null hypothesis probability = 4.996999e-01
Photon flux (15-150 keV) in 3.636 sec: 0.374687 ( -0.067764 0.068812 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.59322e-08 ( -1.2778e-08 1.62449e-08 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.94143 ( -2.76944 1.91072 )
beta : -9.37167 ( 9.37167 19.3716 )
Epeak [keV] : 1.59157 ( -1.59154 19.0538 )
Norm@50keV : 7.83205E-03 ( -0.00324598 0.00761982 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.32 using 59 PHA bins.
# Reduced chi-squared = 1.006 for 55 degrees of freedom
# Null hypothesis probability = 4.624301e-01
Photon flux (15-150 keV) in 3.636 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) = 1.95e-08
S(50-100 keV) = 9.22e-09
T90 vs. Hardness ratio plot
T90 = 3.324000030756 sec.
Hardness ratio (energy fluence ratio) = 0.472821
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 0.621799
Count Ratio (50-100 keV) / (15-25 keV) = 0.0340101
Mask shadow pattern
IMX = -2.899739492053793E-01, IMY = 1.172313939840287E-01
TIME vs. PHA plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 2.048000
TIME vs. DetID plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 2.048000
100 us light curve (15-350 keV)
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 2.048000
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:
-137.283380 -0.312000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
170.0594 -60.6004 7.1 41.2 -36.7 0.3821 1.6 7.7 Cen X-3
186.6473 -62.7730 1.0 33.1 -35.4 2.0772 11.7 0.3 GX 301-2
244.9642 -15.6390 1.0 38.4 87.9 6.4644 11.6 0.9 Sco X-1
255.9613 -37.8288 0.9 16.5 112.2 1.8060 12.5 1.5 4U 1700-377
256.5744 -36.2533 0.0 18.1 112.7 0.3256 2.1 12.2 GX 349+2
263.0089 -24.8160 10.8 30.5 119.3 -0.2255 -1.1 4.2 GX 1+4
264.7005 -44.3055 4.6 13.4 146.7 0.3465 2.5 8.9 4U 1735-44
270.2276 -25.2374 6.3 32.2 131.5 -0.4133 -1.8 10.0 GX 5-1
270.4276 -25.7773 7.1 31.8 132.2 0.3641 1.6 7.1 GRS 1758-258
274.0165 -14.0467 7.9 43.9 130.4 0.9572 1.5 0.9 GX 17+2
275.9846 -30.4229 150.0 29.9 144.9 -0.0158 -0.1 4.6 H1820-303
284.9517 -25.0294 8.1 38.6 151.8 -0.3726 -1.4 8.0 HT1900.1-2455
263.0445 -33.8607 4.1 21.9 125.6 0.4668 2.8 3.2 GX 354-0
266.7964 -27.3604 1.3 29.1 127.4 1.7664 9.1 ------ UNKNOWN
251.5722 -45.6524 3.1 8.2 102.7 0.4900 3.7 ------ UNKNOWN
243.3505 -52.3279 2.3 4.4 22.9 0.6647 5.0 ------ UNKNOWN
341.8266 -52.6094 3.5 50.9 -135.5 3.0309 3.4 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-0.312000 3.324000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
170.3308 -60.7754 14.8 41.0 -36.9 -0.0241 -0.8 9.2 Cen X-3
186.2639 -62.7482 0.0 33.3 -35.4 -0.0157 -0.6 10.9 GX 301-2
245.1041 -15.6964 7.5 38.3 88.1 0.1153 1.5 8.0 Sco X-1
255.9539 -37.6973 4.1 16.6 112.1 -0.0567 -2.8 8.9 4U 1700-377
256.6117 -36.3990 4.9 18.0 112.9 0.0499 2.4 8.6 GX 349+2
262.8124 -24.6318 0.0 30.7 118.9 -0.0088 -0.3 12.7 GX 1+4
264.6576 -44.5943 5.6 13.1 147.4 -0.0411 -2.1 9.4 4U 1735-44
270.2769 -25.1608 3.2 32.3 131.5 0.1122 3.6 4.9 GX 5-1
270.5152 -25.8331 2.9 31.8 132.4 -0.1171 -4.0 12.7 GRS 1758-258
273.9602 -14.0591 113.2 43.9 130.3 0.0078 0.1 3.0 GX 17+2
275.9827 -30.4947 8.3 29.8 144.9 -0.0380 -1.4 8.2 H1820-303
284.9502 -24.9249 5.2 38.7 151.7 0.0832 2.2 4.7 HT1900.1-2455
262.8503 -33.9465 10.2 21.8 125.3 0.0260 1.1 9.6 GX 354-0
280.1939 -54.9656 1.3 17.4 -158.0 0.1763 9.3 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
82.116590 962.486400
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
170.4328 -60.5498 12.2 51.8 5.6 1.5020 0.9 5.6 Cen X-3
186.6871 -62.7556 1.3 44.6 10.2 8.6469 9.1 1.2 GX 301-2
255.9918 -37.8298 1.0 23.7 96.0 8.6267 12.1 0.9 4U 1700-377
256.3870 -36.2578 6.6 24.8 98.8 1.3195 1.8 10.2 GX 349+2
263.0802 -24.7497 16.3 32.8 120.0 0.6986 0.7 3.9 GX 1+4
264.8270 -44.3086 6.0 14.6 100.6 0.8990 1.9 9.2 4U 1735-44
270.2873 -25.0989 3.6 30.8 131.9 2.8435 3.2 1.2 GX 5-1
270.3414 -25.7095 3.7 30.2 131.7 2.7124 3.1 2.9 GRS 1758-258
274.1148 -14.1121 3.9 41.2 140.6 4.7550 3.0 7.8 GX 17+2
275.9306 -30.3142 3.4 24.9 140.8 2.3664 3.4 3.2 H1820-303
284.9678 -24.8675 4.6 30.4 158.2 2.0271 2.5 4.9 HT1900.1-2455
262.9393 -33.9133 4.4 24.3 112.8 1.8746 2.6 5.3 GX 354-0
266.8442 -27.3440 0.7 29.3 124.8 12.5741 15.9 ------ UNKNOWN
243.1221 -52.4431 1.7 21.8 50.9 3.8602 6.6 ------ UNKNOWN
104.8595 -68.6684 5.5 56.3 -28.4 8.2311 2.1 ------ UNKNOWN
335.1282 -23.6205 4.1 50.9 -135.5 14.0825 2.8 ------ UNKNOWN
Plot creation:
Sun May 31 07:32:50 EDT 2015