CHANDRA S3 BACKGROUND
*over the whole chip (8.3 by 8.3 arcmin) *from Blank Field Observations
0.5-2.0 keV --> Model flux 2.9232E-04 photons ( 4.8465E-13 ergs)cm**-2 s**-1 2.0-7.0 keV --> Model flux 7.6094E-04 photons ( 6.0532E-12 ergs)cm**-2 s**-1 7.0-10 keV --> Model flux 1.9948E-02 photons ( 2.9409E-10 ergs)cm**-2 s**-1 0.5-10 keV --> Model flux 2.0906E-02 photons ( 2.9975E-10 ergs)cm**-2 s**-1
model fit
unfodel spectrum
models
telescope = CHANDRA , instrument = ACIS , channel type = PI File integration time 1.1489E+05
0.5-2.0 keV --------------------------------------------------------------------------- --------------------------------------------------------------------------- Model Fit Model Component Parameter Unit Value par par comp 1 1 1 powerlaw PhoIndex 0.9526 +/- 0.5080E-01 2 2 1 powerlaw norm 1.3468E-04 +/- 0.3601E-05 3 3 2 gaussian LineE keV 0.5580 +/- 0.3183E-02 4 4 2 gaussian Sigma keV 7.5000E-02 +/- 0.3282E-02 5 5 2 gaussian norm 9.5589E-05 +/- 0.8034E-05 6 6 3 gaussian LineE keV 1.781 +/- 0.1953E-02 7 7 3 gaussian Sigma keV 4.3000E-02 +/- 0.3624E-02 8 8 3 gaussian norm 3.0996E-05 +/- 0.2143E-05 --------------------------------------------------------------------------- --------------------------------------------------------------------------- Chi-Squared = 205.8770 using 105 PHA bins. Reduced chi-squared = 2.122443 for 97 degrees of freedom Null hypothesis probability = 7.983E-10 XSPEC> flux 0.5 2.0 Model flux 2.9232E-04 photons ( 4.8465E-13 ergs)cm**-2 s**-1 ( 0.500- 2.000) Noticed channels 32 to 136 File observed count rate 0.1685 Model predicted rate : 0.1667 ~1% error --------------------------------------------------------------------------- ---------------------------------------------------------------------------
2.0-7.0 keV --------------------------------------------------------------------------- --------------------------------------------------------------------------- mo = gaussian[1] + powerlaw[2] + gaussian[3] Model Fit Model Component Parameter Unit Value par par comp 1 1 1 gaussian LineE keV 2.155 +/- 0.4032E-01 2 2 1 gaussian Sigma keV 5.9489E-02 +/- 0.6344E-01 3 3 1 gaussian norm 4.0000E-05 frozen 4 4 2 powerlaw PhoIndex 1.5693E-02 +/- 0.5116E-01 5 5 2 powerlaw norm 1.0227E-04 +/- 0.1244E-04 6 6 3 gaussian LineE keV 14.96 +/- 0.3149 7 7 3 gaussian Sigma keV 2.020 +/- 0.7065E-02 8 8 3 gaussian norm 5.488 +/- 4.567 --------------------------------------------------------------------------- --------------------------------------------------------------------------- Chi-Squared = 539.6820 using 343 PHA bins. Reduced chi-squared = 1.606196 for 336 degrees of freedom Null hypothesis probability = 1.096E-11 XSPEC> flux 2 7 Model flux 7.6094E-04 photons ( 6.0532E-12 ergs)cm**-2 s**-1 ( 2.000- 7.000) Noticed channels 137 to 479 File observed count rate 0.2159 Model predicted rate : 0.2100 ~3% error ---------------------------------------------------------------------- ----------------------------------------------------------------------
7.0-9.8 keV --------------------------------------------------------------------------- --------------------------------------------------------------------------- mo = gaussian[1] + gaussian[2] Model Fit Model Component Parameter Unit Value par par comp 1 1 1 gaussian LineE keV 7.500 frozen 2 2 1 gaussian Sigma keV 0.1000 frozen 3 3 1 gaussian norm 1.0575E-04 +/- 0.1961E-04 4 4 2 gaussian LineE keV 12.00 frozen 5 5 2 gaussian Sigma keV 1.631 +/- 0.5150E-02 6 6 2 gaussian norm 0.1830 +/- 0.1858E-02 --------------------------------------------------------------------------- --------------------------------------------------------------------------- Chi-Squared = 480.2856 using 191 PHA bins. Reduced chi-squared = 2.554711 for 188 degrees of freedom XSPEC> flux 7.0 9.8 Model flux 1.6142E-02 photons ( 2.3449E-10 ergs)cm**-2 s**-1 ( 7.000- 9.800) Model flux 1.9948E-02 photons ( 2.9409E-10 ergs)cm**-2 s**-1 ( 6.597- 9.993) Noticed channels 481 to 671 File observed count rate 0.3726 Model predicted rate : 0.3687 ~1% error ---------------------------------------------------------------------- ---------------------------------------------------------------------- 2.0-9.8 keV (attempt) --------------------------------------------------------------------------- --------------------------------------------------------------------------- mo = gaussian[1] + powerlaw[2] + gaussian[3] + gaussian[4] + gaussian[5] --------------------------------------------------------------------------- --------------------------------------------------------------------------- mo = gaussian[1] + powerlaw[2] + gaussian[3] + gaussian[4] + gaussian[5] Model Fit Model Component Parameter Unit Value par par comp 1 1 1 gaussian LineE keV 2.160 frozen 2 2 1 gaussian Sigma keV 4.9700E-02 frozen 3 3 1 gaussian norm 3.0658E-05 +/- 0.2768E-05 4 4 2 powerlaw PhoIndex 0.6180 frozen 5 5 2 powerlaw norm 2.2328E-04 +/- 0.3609E-05 6 6 3 gaussian LineE keV 15.00 frozen 7 7 3 gaussian Sigma keV 2.580 frozen 8 8 3 gaussian norm 3.3819E-02 +/- 0.3004E-02 9 9 4 gaussian LineE keV 7.500 frozen 10 10 4 gaussian Sigma keV 0.1000 frozen 11 11 4 gaussian norm 5.1947E-05 +/- 0.1748E-04 12 12 5 gaussian LineE keV 12.00 frozen 13 13 5 gaussian Sigma keV 1.630 frozen 14 14 5 gaussian norm 0.1800 frozen --------------------------------------------------------------------------- --------------------------------------------------------------------------- Chi-Squared = 1321.104 using 535 PHA bins. Reduced chi-squared = 2.487955 for 531 degrees of freedom Model flux 2.1262E-02 photons ( 3.0891E-10 ergs)cm**-2 s**-1 ( 2.000- 9.993) Noticed channels 137 to 671 File observed count rate 0.5892 Model predicted rate : 0.5884 error 0.14% ---------------------------------------------------------------------- ----------------------------------------------------------------------
0.5-9.8 keV (attempt) --------------------------------------------------------------------------- --------------------------------------------------------------------------- --------------------------------------------------------------------------- --------------------------------------------------------------------------- mo = gaussian[1] + bknpower[2] + gaussian[3] + gaussian[4] + gaussian[5] + gaussian[6] Model Fit Model Component Parameter Unit Value par par comp 1 1 1 gaussian LineE keV 2.160 frozen 2 2 1 gaussian Sigma keV 4.9700E-02 frozen 3 3 1 gaussian norm 4.4110E-05 +/- 0.2724E-05 4 4 2 bknpower PhoIndx1 0.6000 frozen 5 5 2 bknpower BreakE keV 2.000 frozen 6 6 2 bknpower PhoIndx2 -0.2118 +/- 0.1348E-01 7 7 2 bknpower norm 1.3041E-04 +/- 0.2343E-05 8 8 3 gaussian LineE keV 7.500 frozen 9 9 3 gaussian Sigma keV 0.1000 frozen 10 10 3 gaussian norm 6.2615E-05 +/- 0.1663E-04 11 11 4 gaussian LineE keV 12.00 frozen 12 12 4 gaussian Sigma keV 1.630 frozen 13 13 4 gaussian norm 0.1800 frozen 14 14 5 gaussian LineE keV 0.5580 frozen 15 15 5 gaussian Sigma keV 7.5000E-02 frozen 16 16 5 gaussian norm 1.0897E-04 +/- 0.4744E-05 17 17 6 gaussian LineE keV 1.781 frozen 18 18 6 gaussian Sigma keV 4.3000E-02 frozen 19 19 6 gaussian norm 2.7415E-05 +/- 0.1650E-05 --------------------------------------------------------------------------- --------------------------------------------------------------------------- Chi-Squared = 1422.955 using 636 PHA bins. Reduced chi-squared = 2.258658 for 630 degrees of freedom Model flux 2.0906E-02 photons ( 2.9975E-10 ergs)cm**-2 s**-1 ( 0.500- 9.993) Noticed channels 36 to 671 File observed count rate 0.7449 +/-2.54625E-03 cts/s Model predicted rate : 0.7340 error ~1.5%
MODELS power law ------------------------------------------------------------------------ A(E) = K (E/1 keV)**(-par1) ------------------------------------------------------------------------ where : par1 = photon index of power law (dimensionless) K = photons/keV/cm**2/s at 1 keV.
gaussian A simple gaussian line profile. If the width is =< 0, then it is treated as a delta function. ------------------------------------------------------------------------ A(E) = (1./(sqrt(2pi*par2*par2)) * exp(-0.5*((E-par1)/par2)**2)) ------------------------------------------------------------------------ where : par1 = line energy in keV par2 = line width (sigma) in keV K = total photons/cm**2/s in the line
bknpower A broken powerlaw. ------------------------------------------------------------------------ A(E) = K * (E/1 keV)**-par1 for E < par2 = K * par2**(par3-par1) * (E/1 keV)**-par3 for E > par2 ------------------------------------------------------------------------ where : par1 = powerlaw photon index for E < break energy par2 = break point for the energy in keV par3 = powerlaw photon index for E > break energy K = photons/keV/cm**2/s at 1 keV