CalibFluxDen

compute the current flux densities of Cyg A, Tau A and Cas A

0001 function [CasSNow, TotCasErr, CygSNow, TotCygErr, TauSNow, TotTauErr] = CalibFluxDen(v, year)
0002 
0003 %compute the current flux densities of Cyg A, Tau A and Cas A
0004 
0005 % INPUTS
0006 % v is the central frequency
0007 % year is the year you want to fluxes for e.g 2012
0008 
0009 %OUTPUTS
0010 % Flux Density (Jy) as well as errors (+- Jy)
0011 
0012 % References are : WMAP - Weiland, J. et al., 2011, ApJS, 192, 19
0013 %                  Hafez - Hafez, Y. et al., 2008, Mon. Not. R. Astron.Soc. 388, 1775-1786
0014 %                  Vinyaikin - Vinyaikin, E.N., 2007, Astronmy Reports Vol 51, Num 7 570-576
0015 %                  Aller - Aller and Reynolds, 1985, ApJ, 293: l73-L75
0016 
0017 
0018 % for the errors each of the spectral form coefficients had errors associated with
0019 % them. I was previously adding these errors (quadrature). After discussion
0020 % with Paddy this was revealed to be incorrect as errors are correlated. So
0021 % the error on the non log term (dominant term) coefficient will be used to
0022 % represent total error.The same applies for secular decrease
0023 
0024 % modified by OGK 17 April 2012 to make the calculations vectorized.
0025 
0026 
0027 %%%%%%%%%%%%%%%%%%%%%%%%%% Cas A %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
0028 
0029 % the spectral form from WMAP table 17 for epoch 2000
0030 
0031 CaslogS = 2.204 - 0.682*log10(v/40) + 0.038*(log10(v/40)).^2;
0032 
0033 CasFluxDen = 10.^(CaslogS);
0034 
0035 CasErr = 0.002; 
0036 
0037 % secular decrease from Hafez as this decrease can be calculated for 5 GHz (eq 8)
0038 
0039 CasSecDecPercent_perY = 0.68 - 0.15*log10(v);
0040 CasSecDec_perY = CasSecDecPercent_perY/100;
0041 CasYearsPast = year - 2000;
0042 
0043 CasSecDecErr = 0.04/100;
0044 
0045 CasSNow = CasFluxDen.*(1- CasSecDec_perY).^CasYearsPast;
0046 TotCasErr = sqrt((CasErr./CasFluxDen).^2 + (CasYearsPast.*CasSecDecErr./(1 - CasSecDec_perY)).^2 .* CasFluxDen.^2);
0047 
0048 
0049 %%%%%%%%%%%%%%%%%%%%%%%%%% Cyg A %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
0050 
0051 % the spectral form from WMAP table 17
0052 
0053 CyglogS = 1.482 - 1.200*log10(v/40);
0054 
0055 CygFluxDen = 10.^(CyglogS);
0056 
0057 CygErr = 0.003;
0058 
0059 % WMAP p35 'Significant yearly flux variation is not seen for Cyg A'
0060 
0061 CygSNow = CygFluxDen;
0062 TotCygErr = CygErr./CasFluxDen;
0063 
0064 
0065 %%%%%%%%%%%%%%%%%%%%%%%%%% Tau A %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
0066 
0067 % the spectral form from Vinyaikin eq 11 for epoch 2010
0068 
0069 TaulogS = 3.659 - 0.242*log10(v*1000);
0070 
0071 TauFluxDen = 10.^(TaulogS);
0072 
0073 TauErr = 0.068;
0074 
0075 % secular decrease taken from Aller: BEWARE this decrease is for 8 GHz !!!!
0076 
0077 TauSecDecPercent_perY = 0.167;
0078 TauSecDec_perY = TauSecDecPercent_perY/100;
0079 TauYearsPast = year - 2010;
0080 
0081 TauSecDecErr = 0.015/100;
0082 
0083 TauSNow = TauFluxDen.*(1- TauSecDec_perY).^TauYearsPast;
0084 TotTauErr = sqrt((TauErr./TauFluxDen).^2 + (TauYearsPast.*TauSecDecErr./(1 - TauSecDec_perY)).^2 .* TauFluxDen.^2);
0085 
0086 
0087 end
0088 
0089 
0090