The Exploration of Local VolumE Satellites (ELVES) Survey: A Nearly Volume-Limited Sample of Nearby Dwarf Satellite Systems

TL;DR

The ELVES survey provides a comprehensive, volume-limited catalog of dwarf satellites around Milky Way-like galaxies within 12 Mpc, revealing correlations between satellite abundance, host mass, and quenching fractions.

Contribution

This study offers the first large, nearly complete, volume-limited sample of dwarf satellites around MW-like hosts, with consistent detection and measurement methods.

Findings

Satellite abundance correlates with host mass.

Quenched fraction increases with decreasing satellite mass.

Catalogs are complete to M_V~-9 mag and μ_0,V~26.5 mag arcsec$^{-2}$.

Abstract

We present the final results of the Exploration of Local VolumE Satellites (ELVES) Survey, a survey of the dwarf satellites of a nearly volume-limited sample of Milky Way (MW)-like hosts in the Local Volume. Hosts are selected simply via a cut in luminosity ($M_{K_s}<-22.1$ mag) and distance ($D<12$ Mpc). We have cataloged the satellites of 25 of the 31 such hosts, with another five taken from the literature. All hosts are surveyed out to at least 150 projected kpc ($\sim R_\mathrm{vir}/2$) with the majority surveyed to 300 kpc ($\sim R_\mathrm{vir}$). Satellites are detected using a consistent semi-automated algorithm specialized for low surface brightness dwarfs. As shown through extensive tests with injected galaxies, the catalogs are complete to $M_V\sim-9$ mag and $\mu_{0,V}\sim26.5$ mag arcsec$^{-2}$. Candidates are confirmed to be real satellites through distance measurements including redshift, tip of the red giant branch, and surface brightness fluctuations. Across all 30 surveyed hosts, there are 338 confirmed satellites with a further 105 candidates awaiting distance measurement. For the vast majority of these, we provide consistent multi-band S\'{e}rsic photometry. We show that satellite abundance correlates with host mass, with the MW being quite typical amongst comparable systems, and that satellite quenched fraction rises steeply with decreasing satellite mass, mirroring the quenched fraction for the MW and M31. The ELVES survey represents a massive increase in the statistics of surveyed systems with known completeness, and the provided catalogs are a unique dataset to explore various aspects of small-scale structure and dwarf galaxy evolution.