MODEL_AGNfitter.py 文件源码

def maximal_age(z):

    z = np.double(z)
    #Cosmological Constants    
    O_m = 0.266
    O_r =  0.
    O_k= 0.
    O_L = 1. - O_m
    H_0 = 74.3 #km/s/Mpc
    H_sec = H_0 / 3.0857e19 
    secondsinyear = 31556926
    ageoftheuniverse = 13.798e9

    # Equation for the time elapsed since z and now

    a = 1/(1+z)
    E = O_m * (1+z)**3 + O_r *(1+z)**4 + O_k *(1+z) + O_L
    integrand = lambda z : 1 / (1+z)     / sqrt(  O_m * (1+z)**3 + O_r *(1+z)**4 + O_k *(1+z) + O_L  )        

    #Integration
    z_obs = z
    z_cmb = 1089 #As Beta (not cmb). But 1089 (cmb) would be the exagerated maximun possible redshift for the birth 
    z_now = 0


    integral, error = quad( integrand , z_obs, z_cmb) #

    #t = ageoftheuniverse - (integral * (1 / H_sec) / secondsinyear)
    t = (integral * (1 / H_sec)) / secondsinyear

    return t