linear_lognormal_size¶
- skypy.galaxies.morphology.linear_lognormal_size(magnitude, a_mu, b_mu, sigma, size=None)[source] [edit on github]¶
Lognormal size distribution with linear mean.
This function provides a lognormal distribution for the physical size of galaxies with a linear mean, described by equation 3.14 in [1]. See also equation 14 in [2].
- Parameters:
- magnitudefloat or array_like.
Galaxy absolute magnitude at which evaluate the lognormal distribution.
- a_mu, b_mufloat
Linear model parameters describing the mean size of galaxies, (Equation 3.14).
- sigma: float
Standard deviation of the lognormal distribution for the physical radius of galaxies.
- sizeint or tuple of ints, optional.
Output shape. If the given shape is, e.g., (m, n, k), then m * n * k samples are drawn. If size is None (default), a single value is returned if mean and sigma are both scalars. Otherwise, np.broadcast(mean, sigma).size samples are drawn.
- Returns:
- physical_sizenumpy.ndarray or astropy.Quantity
Physical distance for a given galaxy with a given magnitude, in [kpc]. If size is None and magnitude is a scalar, a single sample is returned. If size is ns, different from None, and magnitude is scalar, shape is (ns,). If magnitude has shape (nm,) and size=None, shape is (nm,).
References