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
220.3625 33.5614 0.0187 7.7433 -132.8796 0.3969034 10.336 TRIG_00331332
Foreground time interval of the image:
0.848 19.088 (delta_t = 18.240 [sec])
Background time interval of the image:
-147.731 0.848 (delta_t = 148.579 [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 4.096000
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 4.096000
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 4.096000
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 0.848 sec. to 19.088 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.49753 ( -0.291676 0.299445 )
Norm@50keV : 1.18604E-03 ( -0.000209614 0.00020488 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.45 using 59 PHA bins.
# Reduced chi-squared = 1.236 for 57 degrees of freedom
# Null hypothesis probability = 1.086410e-01
Photon flux (15-150 keV) in 18.24 sec: 0.147966 ( -0.0238065 0.0238124 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.05308e-07 ( -3.99728e-08 4.11788e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.848 sec. to 19.088 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.47208 ( -1.22559 1.38843 )
Epeak [keV] : 960.067 ( )
Norm@50keV : 1.22454E-03 ( -0.000245931 0.00535839 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.45 using 59 PHA bins.
# Reduced chi-squared = 1.258 for 56 degrees of freedom
# Null hypothesis probability = 9.259863e-02
Photon flux (15-150 keV) in 18.24 sec: 0.147945 ( -0.023818 0.023776 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.03664e-07 ( -4.72073e-08 4.25193e-08 ) ergs/cm2
Band function
Time interval is from 0.848 sec. to 19.088 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.00556 ( 1.00618 5.83153 )
beta : -1.67116 ( 1.65753 0.443318 )
Epeak [keV] : 80.2623 ( -82.7042 -82.7042 )
Norm@50keV : 2.30737E-03 ( -0.001229 0.0217591 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.30 using 59 PHA bins.
# Reduced chi-squared = 1.278 for 55 degrees of freedom
# Null hypothesis probability = 8.007738e-02
Photon flux (15-150 keV) in 18.24 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] : 12.8547 (-2.40099 3.24449)
R^2/D10^2 : 2.84503E-02 (-0.0155575 0.0308553)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 78.85 using 59 PHA bins.
# Reduced chi-squared = 1.383 for 57 degrees of freedom
# Null hypothesis probability = 2.923268e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.819e-08 6.229e-09
25- 50 6.188e-08 1.586e-08
50-150 6.422e-08 2.575e-08
15-150 1.443e-07 3.527e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 199.363 (-104.529 -199.363)
Norm : 0.602769 (-0.0968782 0.0968807)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.63 using 59 PHA bins.
# Reduced chi-squared = 1.239 for 57 degrees of freedom
# Null hypothesis probability = 1.059886e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.738e-08 1.557e-08
25- 50 5.266e-08 3.000e-08
50-150 1.155e-07 6.647e-08
15-150 1.956e-07 1.105e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 9.38390 (-4.99976 2.97431)
R1^2/D10^2 : 7.12432E-02 (-0.042161 0.0542711)
kT2 [keV] : 66.4144 (-55.0746 -72.7018)
R2^2/D10^2 : 1.28538E-04 (-8.24291e-05 0.00783952)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.44 using 59 PHA bins.
# Reduced chi-squared = 1.281 for 55 degrees of freedom
# Null hypothesis probability = 7.847198e-02
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.363e-08 1.309e-08
25- 50 5.837e-08 3.179e-08
50-150 1.286e-07 6.616e-08
15-150 2.106e-07 1.033e-07
Peak spectrum fit
Power-law model
Time interval is from 1.084 sec. to 2.084 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.12930 ( -0.481891 0.465805 )
Norm@50keV : 3.28364E-03 ( -0.000860125 0.000860124 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.18 using 59 PHA bins.
# Reduced chi-squared = 1.038 for 57 degrees of freedom
# Null hypothesis probability = 3.960246e-01
Photon flux (15-150 keV) in 1 sec: 0.382034 ( -0.101652 0.102001 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.40178e-08 ( -9.97316e-09 1.02389e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.084 sec. to 2.084 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.383342 ( -2.90081 1.66404 )
Epeak [keV] : 119.690 ( -119.692 -119.692 )
Norm@50keV : 7.21840E-03 ( -0.00721852 0.112065 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.74 using 59 PHA bins.
# Reduced chi-squared = 1.049 for 56 degrees of freedom
# Null hypothesis probability = 3.753234e-01
Photon flux (15-150 keV) in 1 sec: 0.368759 ( -0.108136 0.107437 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.25142e-08 ( -1.06142e-08 1.09014e-08 ) ergs/cm2
Band function
Time interval is from 1.084 sec. to 2.084 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.480501 ( -0.698621 2.97169 )
beta : -10.0000 ( 10 10 )
Epeak [keV] : 130.918 ( -64.6121 369.812 )
Norm@50keV : 6.47497E-03 ( -0.00395715 0.111787 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.75 using 59 PHA bins.
# Reduced chi-squared = 1.068 for 55 degrees of freedom
# Null hypothesis probability = 3.398106e-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] : 19.9432 (-5.60227 8.91316)
R^2/D10^2 : 1.83098E-02 (-0.0126227 0.035345)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.00 using 59 PHA bins.
# Reduced chi-squared = 1.053 for 57 degrees of freedom
# Null hypothesis probability = 3.676385e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.405e-09 8.340e-10
25- 50 6.987e-09 3.952e-09
50-150 2.059e-08 1.191e-08
15-150 2.899e-08 1.588e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 199.363 (-94.6135 -199.363)
Norm : 1.55443 (-0.4184 0.418414)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.24 using 59 PHA bins.
# Reduced chi-squared = 1.074 for 57 degrees of freedom
# Null hypothesis probability = 3.264942e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.871e-09 2.379e-09
25- 50 7.446e-09 4.412e-09
50-150 1.633e-08 9.980e-09
15-150 2.765e-08 1.653e-08
Double BB
R1^2/D10^2 : 2108.34 ( )
kT2 [keV] : 21.3957 (-5.94722 10.724)
R2^2/D10^2 : 1.42396E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.63 using 59 PHA bins.
#Fit statistic : Chi-Squared = 57.60 using 59 PHA bins.
#Fit statistic : Chi-Squared = 57.53 using 59 PHA bins.
# Reduced chi-squared = 1.048 for 55 degrees of freedom
# Reduced chi-squared = 1.047 for 55 degrees of freedom
# Reduced chi-squared = 1.046 for 55 degrees of freedom
# Null hypothesis probability = 3.783575e-01
# Null hypothesis probability = 3.792305e-01
# Null hypothesis probability = 3.815719e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.942e-09 8.650e-10
25- 50 6.568e-09 3.984e-09
50-150 2.115e-08 1.298e-08
15-150 2.966e-08 1.729e-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: 1.49753 ( -0.291676 0.299445 )
Norm@50keV : 1.18604E-03 ( -0.000209614 0.00020488 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.45 using 59 PHA bins.
# Reduced chi-squared = 1.236 for 57 degrees of freedom
# Null hypothesis probability = 1.086410e-01
Photon flux (15-150 keV) in 18.24 sec: 0.147966 ( -0.0238065 0.0238124 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.05308e-07 ( -3.99728e-08 4.11788e-08 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.47208 ( -1.22559 1.38849 )
Epeak [keV] : 960.067 ( )
Norm@50keV : 1.22454E-03 ( -0.000245931 0.00535839 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.45 using 59 PHA bins.
# Reduced chi-squared = 1.258 for 56 degrees of freedom
# Null hypothesis probability = 9.259863e-02
Photon flux (15-150 keV) in 18.24 sec: 0.147945 ( -0.023818 0.023776 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.03664e-07 ( -4.72073e-08 4.25193e-08 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.00556 ( 1.00618 5.83147 )
beta : -1.67116 ( 1.65753 0.443318 )
Epeak [keV] : 80.2623 ( -82.7042 -82.7042 )
Norm@50keV : 2.30737E-03 ( -0.001229 0.0222108 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 70.30 using 59 PHA bins.
# Reduced chi-squared = 1.278 for 55 degrees of freedom
# Null hypothesis probability = 8.007738e-02
Photon flux (15-150 keV) in 18.24 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) = 5.07e-08
S(50-100 keV) = 7.18e-08
T90 vs. Hardness ratio plot
T90 = 17.0879999995232 sec.
Hardness ratio (energy fluence ratio) = 1.41617
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.39473
Count Ratio (50-100 keV) / (15-25 keV) = 0.957071
Mask shadow pattern
IMX = -9.252584379668545E-02, IMY = 9.964078974462079E-02
TIME vs. PHA plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 4.096000
TIME vs. DetID plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 4.096000
100 us light curve (15-350 keV)
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 4.096000
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:
-147.731400 0.848000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.5372 35.4109 7.6 30.8 163.8 -0.2252 -1.5 5.7 Her X-1
267.6986 31.1746 2.1 42.5 162.7 1.2569 5.4 ------ UNKNOWN
260.7128 4.6594 2.8 53.9 -163.6 1.4910 4.1 ------ UNKNOWN
216.1872 10.4138 2.4 29.9 -103.7 0.8248 4.8 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
0.848000 19.088000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.3447 35.4701 12.2 30.6 163.8 -0.0467 -1.0 9.4 Her X-1
255.8568 40.7120 2.4 30.2 153.2 0.2500 4.9 ------ UNKNOWN
145.2535 30.1438 2.2 56.9 0.7 1.2571 5.3 ------ UNKNOWN
255.0211 20.1441 2.4 39.1 -173.5 0.2732 4.9 ------ UNKNOWN
220.3625 33.5614 1.1 7.7 -132.9 0.3970 10.3 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
76.268590 962.419800
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
244.9754 -15.6348 0.6 54.6 -152.7 36.0096 18.2 0.4 Sco X-1
254.6867 35.3171 0.0 28.2 133.6 -0.3380 -0.7 11.3 Her X-1
245.4124 62.1043 3.6 32.6 78.4 2.4160 3.2 ------ UNKNOWN
272.3667 10.6461 2.7 52.7 160.0 9.2078 4.2 ------ UNKNOWN
257.2819 1.6739 2.9 47.0 -178.3 3.0647 4.1 ------ UNKNOWN
169.1687 12.9542 3.0 50.7 -44.4 9.6967 3.8 ------ UNKNOWN
Plot creation:
Sun May 31 06:00:11 EDT 2015