Units
            Length:     m = 10-4cm = 104
                            AU = 1.50x1013 cm
                           ly = 0.95x1018cm
                           pc = 3.09x1018cm = 2.06x105AU    (2.06x105 arcsec/radian)
            Time:        yr = 3.16x107 s
            Velocity:  pc/Myr = 0.98 km/s
            Energy:     E0 = 1 eV = 1.60 x10-12 erg
                                     E0/k = 1.16x104 K
                                     E0/h = 2.42x1014Hz = freq. of 1eV photon
                                     hc/E0 = 12400 = 1.24m = wavelength of 1eV photon
                           Ryd = 2.18x10-11 erg = 13.6 eV
             Flux Density:   1Jy = 10-23 erg/cm2/s/Hz

 

Constants
c=3x1010 cm/s
G = 6.67x10-8dyn cm2 g-2
e = 4.8x10-10 esu
h = 6.63x10-27 erg s              wpe1.gif (952 bytes)= h/2p = 1.05x10-27erg s
me = 0.91x10-27 g                  mec2 = 511keV
mp = 1.67x10-24 g                 mpc2 = 0.938GeV
k = 1.38x10-16 erg/deg = 8.62x10-5 eV/deg             1keV = 1.16x107 K
a = 7.56x10-15 erg cm-3 deg-4         s = ac/4 = 5.67x10-5
R = 8.32x107 erg deg-1 mole-1
a = e2/wpe1.gif (952 bytes)= 1/137
wpe4.gif (1025 bytes)= 1.99 x1033 g        wpe4.gif (1025 bytes)c2 = 1.79x1054 erg
wpe5.gif (980 bytes)= 3.90x1033 erg/s     wpe2.gif (891 bytes)= 7x1010cm
H0 = 70 km/s/Mpc             c/H0 = 4000 Mpc