def Jybeam_to_T(Jybeam, freq, Bmin, Bmaj):
    # https://science.nrao.edu/facilities/vla/proposing/TBconv
    """
    Flux density in Jy/Beam yo Brightness temperature in Kelvin
    freq in GHz
    Bmin and Bmaj in arcseconds
    """
    T = 1.222E3 * (Jybeam * 1000.) / ((freq**2.) * Bmin *Bmaj)
    return T