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
112.0547 75.1000 0.0034 44.6590 -135.7440 58.9031983 56.084 TRIG_00451901
Foreground time interval of the image:
-11.156 36.760 (delta_t = 47.916 [sec])
Background time interval of the image:
-357.051 -289.696 (delta_t = 67.356 [sec])
-239.752 -11.156 (delta_t = 228.596 [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 0.128000
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 0.128000
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 0.128000
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 -11.156 sec. to 36.760 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.34000 ( )
Norm@50keV : 8.24251E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 117.75 using 59 PHA bins.
# Reduced chi-squared = 2.0659 for 57 degrees of freedom
# Null hypothesis probability = 4.050404e-06
Photon flux (15-150 keV) in 47.92 sec: 9.90966 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 3.86643e-05 ( 0 0 ) ergs/cm2
Cutoff power-law model
Time interval is from -11.156 sec. to 36.760 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.830896 ( -0.107116 0.104973 )
Epeak [keV] : 147.995 ( -14.6724 21.4632 )
Norm@50keV : 0.130678 ( -0.0115538 0.0128828 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.67 using 59 PHA bins.
# Reduced chi-squared = 0.7977 for 56 degrees of freedom
# Null hypothesis probability = 8.618086e-01
Photon flux (15-150 keV) in 47.92 sec: 9.54136 ( -0.17596 0.17701 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.83327e-05 ( -5.26018e-07 5.2573e-07 ) ergs/cm2
Band function
Time interval is from -11.156 sec. to 36.760 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.805832 ( -0.113811 0.211238 )
beta : -1.85637 ( 1.85336 0.270564 )
Epeak [keV] : 142.322 ( -35.6369 24.4951 )
Norm@50keV : 0.134270 ( -0.013996 0.0394395 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.34 using 59 PHA bins.
# Reduced chi-squared = 0.8062 for 55 degrees of freedom
# Null hypothesis probability = 8.474574e-01
Photon flux (15-150 keV) in 47.92 sec: 9.52157 ( ) 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] : 21.5311 ( )
R^2/D10^2 : 0.343490 ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 858.31 using 59 PHA bins.
# Reduced chi-squared = 15.058 for 57 degrees of freedom
# Null hypothesis probability = 1.935136e-143
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.426e-06 4.337e-08
25- 50 7.443e-06 1.677e-07
50-150 2.576e-05 4.385e-07
15-150 3.463e-05 4.936e-07
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 199.363 ( )
Norm : 43.7936 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 452.21 using 59 PHA bins.
# Reduced chi-squared = 7.9334 for 57 degrees of freedom
# Null hypothesis probability = 7.005736e-63
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 5.226e-06 9.584e-08
25- 50 1.005e-05 1.653e-07
50-150 2.205e-05 3.690e-07
15-150 3.732e-05 5.918e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 9.42777 (-0.580737 0.608677)
R1^2/D10^2 : 3.04013 (-0.520736 0.663582)
kT2 [keV] : 32.2167 (-1.56473 1.86841)
R2^2/D10^2 : 6.95197E-02 (-0.0131401 0.0143422)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 45.52 using 59 PHA bins.
# Reduced chi-squared = 0.8276 for 55 degrees of freedom
# Null hypothesis probability = 8.152224e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.095e-06 1.653e-07
25- 50 9.163e-06 2.588e-07
50-150 2.590e-05 6.493e-07
15-150 3.816e-05 7.643e-07
Peak spectrum fit
Power-law model
Time interval is from 6.904 sec. to 7.904 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.969015 ( -0.0559474 0.0555546 )
Norm@50keV : 0.251201 ( -0.00834604 0.00833068 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.35 using 59 PHA bins.
# Reduced chi-squared = 1.076 for 57 degrees of freedom
# Null hypothesis probability = 3.227738e-01
Photon flux (15-150 keV) in 1 sec: 28.8795 ( -0.974925 0.975475 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.74683e-06 ( -9.48529e-08 9.48849e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 6.904 sec. to 7.904 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.680225 ( -0.234004 0.222637 )
Epeak [keV] : 276.950 ( -96.5161 638.087 )
Norm@50keV : 0.333578 ( -0.0641857 0.0832246 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.40 using 59 PHA bins.
# Reduced chi-squared = 1.007 for 56 degrees of freedom
# Null hypothesis probability = 4.599092e-01
Photon flux (15-150 keV) in 1 sec: 28.6148 ( -0.9925 0.994 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.73168e-06 ( 0 0 ) ergs/cm2
Band function
Time interval is from 6.904 sec. to 7.904 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.311779 ( -4.37169 -4.37169 )
beta : -1.08622 ( -0.0583998 0.0585335 )
Epeak [keV] : 71.1427 ( -16.735 135.37 )
Norm@50keV : 1.33074 ( -1.3276 9.70307 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.98 using 59 PHA bins.
# Reduced chi-squared = 0.9634 for 55 degrees of freedom
# Null hypothesis probability = 5.520006e-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] : 23.3719 ( )
R^2/D10^2 : 0.879615 ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 197.62 using 59 PHA bins.
# Reduced chi-squared = 3.4670 for 57 degrees of freedom
# Null hypothesis probability = 2.114855e-17
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 8.640e-08 5.645e-09
25- 50 4.730e-07 2.410e-08
50-150 1.928e-06 9.300e-08
15-150 2.488e-06 1.005e-07
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 199.363 ( )
Norm : 117.971 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 356.22 using 59 PHA bins.
# Reduced chi-squared = 6.2495 for 57 degrees of freedom
# Null hypothesis probability = 7.159781e-45
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.938e-07 9.850e-09
25- 50 5.651e-07 1.955e-08
50-150 1.239e-06 4.300e-08
15-150 2.098e-06 7.500e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 10.5190 (-1.4815 1.65485)
R1^2/D10^2 : 5.81259 (-1.79534 2.93241)
kT2 [keV] : 41.9613 (-6.37086 11.5148)
R2^2/D10^2 : 0.119525 (-0.0601258 0.0815684)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.16 using 59 PHA bins.
# Reduced chi-squared = 0.9847 for 55 degrees of freedom
# Null hypothesis probability = 5.067895e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.592e-07 1.935e-08
25- 50 5.360e-07 5.715e-08
50-150 2.050e-06 3.390e-07
15-150 2.745e-06 4.190e-07
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: 1.34000 ( )
Norm@50keV : 8.24251E-02 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 117.75 using 59 PHA bins.
# Reduced chi-squared = 2.0659 for 57 degrees of freedom
# Null hypothesis probability = 4.050404e-06
Photon flux (15-150 keV) in 47.92 sec: 9.90966 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 3.86643e-05 ( 0 0 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.830896 ( -0.107116 0.104973 )
Epeak [keV] : 147.995 ( -14.6724 21.4632 )
Norm@50keV : 0.130678 ( -0.0115538 0.0128828 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.67 using 59 PHA bins.
# Reduced chi-squared = 0.7977 for 56 degrees of freedom
# Null hypothesis probability = 8.618086e-01
Photon flux (15-150 keV) in 47.92 sec: 9.54136 ( -0.17596 0.17701 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.83327e-05 ( -5.26018e-07 5.2573e-07 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.805832 ( -0.113811 0.211238 )
beta : -1.85637 ( 1.85336 0.270564 )
Epeak [keV] : 142.322 ( -34.8733 24.4949 )
Norm@50keV : 0.134270 ( -0.013996 0.0394395 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 44.34 using 59 PHA bins.
# Reduced chi-squared = 0.8062 for 55 degrees of freedom
# Null hypothesis probability = 8.474574e-01
Photon flux (15-150 keV) in 47.92 sec: 9.52157 ( ) 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) = 8.80e-06
S(50-100 keV) = 1.39e-05
T90 vs. Hardness ratio plot
T90 = 25.7839999198914 sec.
Hardness ratio (energy fluence ratio) = 1.57955
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.86353
Count Ratio (50-100 keV) / (15-25 keV) = 1.8509
Mask shadow pattern
IMX = -7.077538567061747E-01, IMY = 6.896085308524967E-01
TIME vs. PHA plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 0.128000
TIME vs. DetID plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 0.128000
100 us light curve (15-350 keV)
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 0.128000
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:
-357.051400 -289.695600
-239.752000 -11.156000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.4365 35.3552 1.3 22.3 51.2 2.0883 8.6 1.3 Her X-1
288.8255 10.8677 7.1 54.8 10.9 1.5926 1.6 4.9 GRS 1915+105
299.5980 35.1912 0.8 39.0 -18.2 3.8512 13.7 0.7 Cyg X-1
308.1062 41.0022 2.0 39.2 -32.3 1.8130 5.8 3.0 Cyg X-3
318.8288 26.1378 3.2 56.3 -28.3 3.8259 3.6 ------ UNKNOWN
327.7452 41.7092 2.8 49.1 -48.0 4.2081 4.1 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-11.156000 36.760000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
254.7002 35.3686 19.7 22.3 50.6 0.1497 0.6 12.0 Her X-1
288.7957 10.9447 36.3 54.7 10.9 0.2920 0.3 0.2 GRS 1915+105
299.6107 35.2057 183.8 39.0 -18.2 -0.0276 -0.1 1.0 Cyg X-1
308.1204 40.8057 5.9 39.3 -32.0 1.1211 2.0 8.8 Cyg X-3
233.3945 46.5055 3.4 15.5 110.2 0.9929 3.4 ------ UNKNOWN
146.7516 55.8934 3.1 51.4 -165.9 3.1038 3.8 ------ UNKNOWN
152.6195 74.4479 3.1 37.7 -147.6 1.8446 3.8 ------ UNKNOWN
319.5743 73.6370 2.8 30.0 -90.4 2.5615 4.2 ------ UNKNOWN
112.0548 75.1000 0.2 44.7 -135.7 58.9019 56.1 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
803.048600 962.306400
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
229.4232 54.9050 2.6 43.7 52.3 2.5913 4.4 ------ UNKNOWN
190.5380 66.8996 2.2 24.6 72.0 1.0326 5.3 ------ UNKNOWN
266.9600 65.8066 2.3 38.2 21.0 1.1384 5.1 ------ UNKNOWN
286.8404 52.9584 3.1 51.9 8.7 1.6036 3.7 ------ UNKNOWN
121.4171 34.7680 3.5 40.6 172.8 0.7992 3.3 ------ UNKNOWN
112.3095 17.1233 2.4 58.0 -175.6 3.7773 4.7 ------ UNKNOWN
Plot creation:
Sat May 30 22:23:13 EDT 2015