A pilot survey of stellar tidal streams in nearby spiral galaxies

TL;DR

This study conducts a pioneering deep imaging survey of stellar tidal streams in approximately 50 nearby spiral galaxies to understand their prevalence, characteristics, and implications for galaxy formation theories.

Contribution

It is the first systematic, wide-field imaging survey of stellar tidal streams in nearby Milky Way-like galaxies, providing detailed data for comparison with cosmological simulations.

Findings

Revealed detailed external views of stellar streams in spiral galaxies.

Estimated the incidence and properties of tidal streams in the local universe.

Established a statistical basis for comparing observed streams with theoretical models.

Abstract

Within the hierarchical framework for galaxy formation, merging and tidal interactions are expected to shape large galaxies to this day. While major mergers are quite rare at present, minor mergers and satellite disruptions - which result in stellar streams - should be common, and are indeed seen in both the Milky Way and the Andromeda Galaxy. As a pilot study, we have carried out ultra-deep, wide-field imaging of some spiral galaxies in the Local Volume, which has revealed external views of such stellar tidal streams at unprecedented detail, with data taken at small robotic telescopes (0.1-0.5-meter) that provide exquisite surface brightness sensitivity. The goal of this project is to undertake the first systematic and comprehensive imaging survey of stellar tidal streams, from a sample of ~50 nearby Milky-Way-like spiral galaxies within 15 Mpc, that features a surface brightness sensitivity of ~ 30 mag/arcsec^2 The survey will result in estimates of the incidence, size/geometry and stellar luminosity/mass distribution of such streams. This will not only put our Milky Way and M31 in context but, for the first time, also provide an extensive statistical basis for comparison with state-of-the-art, self-consistent cosmological simulations of this phenomenon.