Streaming motion in Leo I

TL;DR

This paper investigates whether Leo I dwarf galaxy is in equilibrium or undergoing tidal disruption by analyzing recent observational data, revealing modest signs of tidal effects especially in outer regions.

Contribution

It applies advanced statistical tools to observational data to detect and characterize tidal disruption in Leo I, providing new insights into its dynamical state.

Findings

Tidal disruption detected in Leo I, especially in outer regions.

Disruption effects are modest, not indicating complete disintegration.

Statistical methods effectively identify tidal features in dwarf galaxies.

Abstract

Whether a dwarf spheroidal galaxy is in equilibrium or being tidally disrupted by the Milky Way is an important question for the study of its dark matter content and distribution. This question is investigated using 328 recent observations from the dwarf spheroidal Leo I. For Leo I, tidal disruption is detected, at least for stars sufficiently far from the center, but the effect appears to be quite modest. Statistical tools include isotonic and split point estimators, asymptotic theory, and resampling methods.