Structure and dynamics in low density regions: galaxy-galaxy correlations inside cosmic voids

Abstract

We compute the galaxy-galaxy correlation function of low-luminosity SDSS-DR7 galaxies $(-20<M_{\mathrm{r}}-5{\log }_{10}(h)<-18)$ inside cosmic voids identified in a volume limited sample of galaxies at $z=0.085$. To identify voids, we use bright galaxies with $M_{\mathrm{r}}-5{\log }_{10}(h)<-20.0$. We find that structure in voids as traced by faint galaxies is mildly non-linear as compared with the general population of galaxies with similar luminosities. This implies a redshift-space correlation function with a similar shape than the real-space correlation albeit a normalization factor. The redshift space distortions of void galaxies allow to calculate pairwise velocity distributions which are consistent with an exponential model with a pairwise velocity dispersion of $w\sim 50-70$ km/s, significantly lower than the global value of $w\sim 500$ km/s. We also find that the internal structure of voids as traced by faint galaxies is independent of void environment, namely the correlation functions of galaxies residing in void-in-void or void-in-shell regions are identical within uncertainties. We have tested all our results with the semi-analytic catalogue MDPL2-\textsc{Sag} finding a suitable agreement with the observations in all topics studied.

Submitted to MNRAS, comments are welcome

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Cited by in corpus (10)

• The Gravitational Lensing Signatures of BOSS Voids in the Cosmic Microwave Background
• How galaxies populate haloes in very low-density environments? An analysis of the Halo Occupation Distribution in cosmic voids
• Local and large-scale effects on the astrophysics of void-galaxies
• How do galaxies populate halos in extreme density environments? An analysis of the Halo Occupation Distribution in SDSS
• Hickson-like compact groups inhabiting different environments
• Imprints of the cosmic void evolution on the baryon processes inside galaxy haloes
• The galaxy bias profile of cosmic voids
• Environmental effects on associations of dwarf galaxies
• Traces of the evolution of cosmic void galaxies: An Integral Field Spectroscopy based analysis
• The evolution of the halo occupation distribution in cosmic voids