# A multi-epoch kinematic study of the remote dwarf spheroidal galaxy Leo   II

**Authors:** Meghin Spencer, Mario Mateo, Matthew Walker, Edward Olszewski

arXiv: 1702.08836 · 2017-03-01

## TL;DR

This study provides a detailed kinematic and metallicity analysis of Leo II dwarf galaxy using spectroscopic data, revealing its velocity, metallicity gradient, and potential multiple populations.

## Contribution

It offers the first extensive spectroscopic survey of Leo II's red giants, identifying new members and analyzing its kinematic and chemical properties.

## Key findings

- Systemic velocity of 78.3 km/s with low dispersion
- Strong metallicity gradient of -1.53 dex/kpc
- Evidence of two chemodynamic populations, but weak signal

## Abstract

We conducted a large spectroscopic survey of 336 red giants in the direction of the Leo II dwarf galaxy using Hectochelle on the MMT, and conclude that 175 of them are members based on their radial velocities and surface gravities. Of this set, 40 stars have never before been spectroscopically observed. The systemic velocity of the dwarf is 78.3+-0.6 km/s with a velocity dispersion of 7.4+-0.4 km/s . We identify one star beyond the tidal radius of Leo II but find no signatures of uniform rotation, kinematic asymmetries, or streams. The stars show a strong metallicity gradient of -1.53+-0.10 dex/kpc and have a mean metallicity of -1.70+-0.02 dex. There is also evidence of two different chemodynamic populations, but the signal is weak. A larger sample of stars would be necessary to verify this feature.

## Full text

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## Figures

18 figures with captions in the complete paper: https://tomesphere.com/paper/1702.08836/full.md

## References

43 references — full list in the complete paper: https://tomesphere.com/paper/1702.08836/full.md

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Source: https://tomesphere.com/paper/1702.08836