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
20.8011 38.1226 0.0060 31.9507 -179.9777 3.7020476 32.348 TRIG_00335895
Foreground time interval of the image:
-4.699 62.660 (delta_t = 67.359 [sec])
Background time interval of the image:
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 88.000000
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 88.000000
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 88.000000
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 -68.980 sec. to 62.660 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.87892 ( -0.0858404 0.0871586 )
Norm@50keV : 2.10925E-03 ( -0.000113307 0.000112545 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 69.73 using 59 PHA bins.
# Reduced chi-squared = 1.223 for 57 degrees of freedom
# Null hypothesis probability = 1.200132e-01
Photon flux (15-150 keV) in 131.6 sec: 0.300028 ( -0.0146553 0.0146729 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.55176e-06 ( -1.36224e-07 1.37088e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -68.980 sec. to 62.660 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.939746 ( -0.443983 0.401037 )
Epeak [keV] : 49.8558 ( -5.35506 8.06493 )
Norm@50keV : 6.91096E-03 ( -0.00271486 0.00516203 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.62 using 59 PHA bins.
# Reduced chi-squared = 0.9218 for 56 degrees of freedom
# Null hypothesis probability = 6.411172e-01
Photon flux (15-150 keV) in 131.6 sec: 0.286245 ( -0.015617 0.015642 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.33685e-06 ( -1.55564e-07 1.59091e-07 ) ergs/cm2
Band function
Time interval is from -68.980 sec. to 62.660 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.939698 ( -0.296094 0.356326 )
beta : -10.00000 ( 10 20 )
Epeak [keV] : 49.8466 ( -5.33905 6.34354 )
Norm@50keV : 6.91098E-03 ( -0.00199058 0.00516765 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 51.62 using 59 PHA bins.
# Reduced chi-squared = 0.9386 for 55 degrees of freedom
# Null hypothesis probability = 6.044785e-01
Photon flux (15-150 keV) in 131.6 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 2.40442e-06 ( -2.4035e-06 -1.4909e-07 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 11.2850 (-0.612319 0.649213)
R^2/D10^2 : 8.86868E-02 (-0.0170861 0.0210813)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 107.68 using 59 PHA bins.
# Reduced chi-squared = 1.8891 for 57 degrees of freedom
# Null hypothesis probability = 5.755061e-05
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.120e-07 2.652e-08
25- 50 9.113e-07 4.461e-08
50-150 6.683e-07 7.297e-08
15-150 1.892e-06 1.092e-07
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 82.7889 (-12.2866 15.9668)
Norm : 1.39221 (-0.102009 0.111967)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 53.66 using 59 PHA bins.
# Reduced chi-squared = 0.9414 for 57 degrees of freedom
# Null hypothesis probability = 6.011179e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.764e-07 3.158e-08
25- 50 7.906e-07 3.987e-08
50-150 1.142e-06 1.341e-07
15-150 2.409e-06 1.494e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 6.72292 (-1.17532 1.25221)
R1^2/D10^2 : 0.393776 (-0.149431 0.304204)
kT2 [keV] : 19.3248 (-3.34932 5.78651)
R2^2/D10^2 : 7.64064E-03 (-0.0047286 0.00909196)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 49.68 using 59 PHA bins.
# Reduced chi-squared = 0.9033 for 55 degrees of freedom
# Null hypothesis probability = 6.773187e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.335e-07 1.197e-07
25- 50 8.125e-07 1.720e-07
50-150 1.048e-06 4.776e-07
15-150 2.294e-06 6.193e-07
Peak spectrum fit
Power-law model
Time interval is from 17.596 sec. to 18.596 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.52253 ( -0.22706 0.230223 )
Norm@50keV : 1.01785E-02 ( -0.00137304 0.00135987 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.20 using 59 PHA bins.
# Reduced chi-squared = 1.021 for 57 degrees of freedom
# Null hypothesis probability = 4.308826e-01
Photon flux (15-150 keV) in 1 sec: 1.27853 ( -0.16874 0.169051 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.62134e-08 ( -1.40881e-08 1.4248e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 17.596 sec. to 18.596 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.46687 ( -0.962227 1.24824 )
Epeak [keV] : 476.502 ( -476.714 -476.714 )
Norm@50keV : 1.08724E-02 ( -0.00854378 0.0222831 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.19 using 59 PHA bins.
# Reduced chi-squared = 1.039 for 56 degrees of freedom
# Null hypothesis probability = 3.947177e-01
Photon flux (15-150 keV) in 1 sec: 1.27571 ( -0.17345 0.17092 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.58702e-08 ( -1.53138e-08 1.45168e-08 ) ergs/cm2
Band function
Time interval is from 17.596 sec. to 18.596 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.32622 ( 1.23169 5.9311 )
beta : -1.60518 ( 1.55177 0.255878 )
Epeak [keV] : 159.077 ( -89.1646 -89.1646 )
Norm@50keV : 1.29370E-02 ( -0.00409094 0 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.14 using 59 PHA bins.
# Reduced chi-squared = 1.057 for 55 degrees of freedom
# Null hypothesis probability = 3.603869e-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] : 14.4339 (-2.324 2.9147)
R^2/D10^2 : 0.163440 (-0.0779875 0.1419)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 73.94 using 59 PHA bins.
# Reduced chi-squared = 1.297 for 57 degrees of freedom
# Null hypothesis probability = 6.514960e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.169e-09 1.771e-09
25- 50 2.747e-08 5.565e-09
50-150 3.826e-08 1.070e-08
15-150 7.290e-08 1.468e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 199.363 (-84.8516 -199.363)
Norm : 5.22450 (-0.67543 0.676279)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.46 using 59 PHA bins.
# Reduced chi-squared = 1.026 for 57 degrees of freedom
# Null hypothesis probability = 4.215691e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.301e-08 7.300e-09
25- 50 2.503e-08 1.392e-08
50-150 5.489e-08 3.014e-08
15-150 9.292e-08 5.125e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 6.75715 (-3.25525 4.9334)
R1^2/D10^2 : 1.51126 (-1.18053 17.4074)
kT2 [keV] : 26.0460 (-9.17105 -26.319)
R2^2/D10^2 : 1.65090E-02 (-0.0156714 0.0637243)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.94 using 59 PHA bins.
# Reduced chi-squared = 1.090 for 55 degrees of freedom
# Null hypothesis probability = 3.013134e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.257e-08 7.130e-09
25- 50 2.465e-08 1.293e-08
50-150 5.703e-08 3.239e-08
15-150 9.425e-08 5.055e-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: 1.92300 ( -0.0849418 0.0863739 )
Norm@50keV : 3.24546E-03 ( -0.000173524 0.000172349 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.91 using 59 PHA bins.
# Reduced chi-squared = 1.244 for 57 degrees of freedom
# Null hypothesis probability = 1.018471e-01
Photon flux (15-150 keV) in 67.36 sec: 0.470372 ( -0.0228231 0.0228548 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.01049e-06 ( -1.05319e-07 1.0595e-07 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.857823 ( -0.455368 0.411501 )
Epeak [keV] : 47.5560 ( -4.61761 6.06521 )
Norm@50keV : 1.23841E-02 ( -0.00494844 0.00949796 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 48.28 using 59 PHA bins.
# Reduced chi-squared = 0.8621 for 56 degrees of freedom
# Null hypothesis probability = 7.588772e-01
Photon flux (15-150 keV) in 67.36 sec: 0.445654 ( -0.024394 0.024441 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.83191e-06 ( -1.18237e-07 1.21093e-07 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.798644 ( -0.441078 1.45595 )
beta : -3.05320 ( 3.05337 0.839563 )
Epeak [keV] : 46.8105 ( -11.1351 6.27669 )
Norm@50keV : 1.34600E-02 ( -0.00576226 0.114011 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 47.91 using 59 PHA bins.
# Reduced chi-squared = 0.8712 for 55 degrees of freedom
# Null hypothesis probability = 7.398094e-01
Photon flux (15-150 keV) in 67.36 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 1.83984e-06 ( -1.83937e-06 -1.20904e-07 ) ergs/cm2
S(25-50 keV) vs. S(50-100 keV) plot
S(25-50 keV) = 7.39e-07
S(50-100 keV) = 8.04e-07
T90 vs. Hardness ratio plot
T90 = 102.315999984741 sec.
Hardness ratio (energy fluence ratio) = 1.08796
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.2518
Count Ratio (50-100 keV) / (15-25 keV) = 0.697659
Mask shadow pattern
IMX = -6.236743208708314E-01, IMY = 2.432135093438287E-04
TIME vs. PHA plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 88.000000
TIME vs. DetID plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 88.000000
100 us light curve (15-350 keV)
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 88.000000
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:
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-4.699400 62.660000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
83.6358 22.0018 0.4 23.7 -2.7 2.7939 29.3 0.8 Crab
359.4898 30.4090 2.6 50.6 173.2 1.1856 4.4 ------ UNKNOWN
94.4180 9.8346 2.5 39.2 4.9 0.6306 4.6 ------ UNKNOWN
20.8011 38.1226 0.4 32.0 -180.0 3.7022 32.3 ------ UNKNOWN
41.9482 61.6059 2.3 31.6 -127.6 0.5893 4.9 ------ UNKNOWN
86.6948 70.2221 3.1 41.0 -98.2 1.6340 3.7 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
184.500600 958.400610
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
68.7617 43.7887 2.6 36.2 54.8 3.6799 4.4 ------ UNKNOWN
18.2083 -14.0697 2.0 52.3 172.5 8.1536 5.7 ------ UNKNOWN
29.5799 30.1600 2.6 10.8 124.5 1.5897 4.5 ------ UNKNOWN
313.0949 57.7400 3.4 47.0 -53.1 8.8916 3.4 ------ UNKNOWN
330.3390 32.7161 3.4 40.9 -92.4 8.6043 3.4 ------ UNKNOWN
337.7811 12.8726 3.1 45.7 -122.4 8.8050 3.8 ------ UNKNOWN
Plot creation:
Sun May 31 05:25:05 EDT 2015