utils_pro.py 文件源码

def calc_rate(redshift):
    """Calculate the rate, kpc/px."""
    # Init
    # Hubble constant at z = 0
    H0 = 71.0
    # Omega0, total matter density
    Om0 = 0.27
    # Cosmo
    cosmo = FlatLambdaCDM(H0=H0, Om0=Om0)
    # Angular diameter distance, [Mpc]
    dA = cosmo.angular_diameter_distance(redshift)
    # Resolution of Chandra
    rate_px = 0.492 * au.arcsec  # [arcmin/px]
    rate_px_rad = rate_px.to(au.rad)
    # rate
    rate = dA.value * rate_px_rad.value  # [Mpc/px]

    return rate