Galaxy clustering dependence on the [O ii] emission line luminosity in the local Universe

Abstract

We study the galaxy clustering dependence on the [O ii] emission line luminosity in the SDSS DR7 Main galaxy sample at mean redshift z ∼ 0.1. We select volumelimited samples of galaxies with different [O ii] luminosity thresholds and measure their projected, monopole and quadrupole two-point correlation functions. We model these observations using the 1h −1 Gpc MultiDark Planck cosmological simulation and generate light-cones with the SUrvey GenerAtoR algorithm. To interpret our results, we adopt a modified (Sub)Halo Abundance Matching scheme, accounting for the stellar mass incompleteness of the emission line galaxies. The satellite fraction constitutes an extra parameter in this model and allows to optimize the clustering fit on both small and intermediate scales (i.e. r p 30 h −1 Mpc), with no need of any velocity bias correction. We find that, in the local Universe, the [O ii] luminosity correlates with all the clustering statistics explored and with the galaxy bias. This latter quantity correlates more strongly with the SDSS r-band magnitude than [O ii] luminosity. In conclusion, we propose a straightforward method to produce reliable clustering models, entirely built on the simulation products, which provides robust predictions of the typical ELG host halo masses and satellite fraction values. The SDSS galaxy data, MultiDark mock catalogues and clustering results are made publicly available.

[O ii] emitters in MultiDark-Galaxies and DEEP2

“…We find that the SAG HODs peak at higher halo masses compared to the other two SAMs. The mean halo masses predicted by the sag, sage and galacticus model galaxies are in agreement with the results of Favole et al (2016a) for BOSS [O ii] ELGs at z ∼ 0.8 and Favole et al (2017) for SDSS [O ii] ELGs at z ∼ 0.1.…”

“…10 displays the comparison between the gas-phase oxygen abundances of our SAM galaxies computed using Eq. 18 and the observed abundance of the SDSS [O ii] ELGs at z ∼ 0.1 from Favole et al (2017). The SDSS metallicity values have been derived from the MPA-JHU DR7 13 catalogue of spectrum measurements and are built according to the works of Tremonti et al (2004) and Brinchmann et al (2004).…”

“…Figure10. Mean gas-phase oxygen abundance in bins of stellar mass of the SDSS emission line galaxies at z ∼ 0.1(Favole et al 2017) compared to the MultiDark-Galaxies models. The abundance is computed for the SAMs using Eq.…”

Measuring the growth of structure by matching dark matter haloes to galaxies with VIPERS and SDSS

“…Scatter was not needed to fit the VIPERS data, but a degree of intrinsic scatter is expected in the relationship between galaxy and halo properties. More flexible SHAM models can also be used to model samples that suffer from incompleteness (Favole et al 2016a;Rodríguez-Torres et al 2017;Favole et al 2017) or completeness corrections can be inferred from deeper samples. Secondary dependencies that are a signature of assembly bias such as the halo formation time can also improve the precision of the SHAM model (Hearin & Watson 2013;Miyatake et al 2016;Montero-Dorta et al 2017;Niemiec et al 2018;Lin et al 2016).…”

“…We compute the redshift-space correlation function ξ(r p , π) for the galaxy surveys using the Landy-Szalay estimator (Landy & Szalay 1993). We employ two correlation function code implementations, that of Favole et al (2017) function is present both in the galaxy and halo measurements, so we do not make any additional corrections. We compute the projected correlation functions for the SHAM models at the redshifts of the MultiDark snapshots, w halo p (r p , z|n), where n is the number density of the galaxy sample.…”