# The galaxy luminosity function in the LAMOST Complete Spectroscopic Survey of Pointing Area at the Southern Galactic Cap

## TL;DR

This paper calculates galaxy luminosity functions in multiple optical bands using data from the LAMOST survey in the Southern Galactic Cap, providing new measurements and insights into galaxy populations.

## Contribution

It presents the first LFs derived from the LaCoSSPAr survey data, including separate LFs for emission and absorption line galaxies, revealing bi-modality in passive galaxies.

## Key findings

- LF parameters consistent with previous studies
- Detection of a dip in absorption line galaxy LF at r~18.5
- Absorption galaxy LF fitted by a double-Gaussian, indicating bi-modality

## Abstract

We present optical luminosity functions (LFs) of galaxies in the $^{0.1}g$, $^{0.1}r$, and $^{0.1}i$ bands, calculated using data in $\sim 40$ $deg^{2}$ sky area of LAMOST Complete Spectroscopic Survey of Pointing Area (LaCoSSPAr) in Southern Galactic Cap. Redshifts for galaxies brighter $r = 18.1$ were obtained mainly with LAMOST. In each band, LFs derived using both parametric and non-parametric maximum likelihood methods agree well with each other. In the $^{0.1}r$ band, our fitting parameters of the Schechter function are $\phi_{*}=(1.65\pm0.36)\times10^{-2}h^{3}Mpc^{-3}$, $M_{*}=-20.69\pm0.06$ mag, and $\alpha=-1.12\pm0.08$, in agreements with previous studies. Separate LFs are also derived for emission line galaxies and absorption line galaxies, respectively. The LFs of absorption line galaxies show a dip at $^{0.1}r \sim 18.5$ and can be well fitted by a double-Gaussian function, suggesting a bi-modality in passive galaxies.