create_galaxy_counts

macauff.create_galaxy_counts(cmau_array, mag_bins, z_array, wav, alpha0, alpha1, weight, ab_offset, filter_name, al_grid)

Create a simulated distribution of galaxy magnitudes for a particular bandpass by consideration of double Schechter functions (for blue and red galaxies) in a specified range of redshifts, following [1].

Parameters:

cmau_arraynumpy.ndarray

Array holding the c/m/a/u values that describe the parameterisation of the Schechter functions with wavelength, following Wilson (2022, RNAAS, 6, 60) [1]. Shape should be (5, 2, 4), with 5 parameters for both blue and red galaxies.

mag_binsnumpy.ndarray

The apparent magnitudes at which to evaluate the on-sky differential galaxy density.

z_arraynumpy.ndarray

Redshift bins to evaluate Schechter densities in the middle of.

wavfloat

The wavelength, in microns, of the bandpass observations should be simulated in. Should likely be the effective wavelength.

alpha0list of numpy.ndarray or numpy.ndarray

List of arrays of parameters \(\alpha_{i, 0}\) used to calculate Dirichlet-distributed SED coefficients. Should either be a two-element list of arrays of 5 elements, or an array of shape (2, 5), with coefficients for blue galaxies before red galaxies. See [2] and [3] for more details.

alpha1list of numpy.ndarray or numpy.ndarray

\(\alpha_{i, 1}\) used in the calculation of Dirichlet-distributed SED coefficients. Two-element list or (2, 5) shape array of blue then red galaxy coefficients.

weightlist of numpy.ndarray or numpy.ndarray

Corresponding weights for the derivation of Dirichlet kcorrect coefficients. Must match shape of alpha0 and alpha1.

ab_offsetfloat

Zeropoint offset for differential galaxy count observations in a non-AB magnitude system. Must be in the sense of m_desired = m_AB - offset.

filter_namestr

speclite compound filterset-filter name for the response curve of the particular observations. If observations are in a filter system not provided by speclite, response curve can be generated using generate_speclite_filters.

al_gridlist or numpy.ndarray of floats

The reddenings at infinity by which to extinct all galaxy magnitudes, for various different potential sub-sightlines within a field of view.

Returns:

gal_densnumpy.ndarray

Simulated numbers of galaxies per square degree per magnitude in the specified observed bandpass.

References

[1] (1,2)

Wilson T. J. (2022), RNAAS, 6, 60

[2]

Herbel J., Kacprzak T., Amara A., et al. (2017), JCAP, 8, 35

[3]

Blanton M. R., Roweis S. (2007), AJ, 133, 734