SkyMapper stellar parameters for Galactic Archaeology on a grand-scale

TL;DR

This paper evaluates SkyMapper's photometry for Galactic Archaeology, developing methods to calibrate zero-points and link colour indices to stellar parameters, enabling precise stellar characterization.

Contribution

It introduces a formalism for homogenizing zero-points and deriving stellar parameters from SkyMapper data, enhancing its utility for Galactic studies.

Findings

Achieves better than 100K precision in effective temperature for late-type stars

Provides ~0.2 dex metallicity estimates for stars above -2 metallicity

Distinguishes M-dwarfs from M-giants reliably

Abstract

The SkyMapper photometric surveys provides uvgriz photometry for several millions sources in the Southern sky. We use DR1.1 to explore the quality of its photometry, and develop a formalism to homogenise zero-points across the sky using stellar effective temperatures. Physical flux transformations, and zero-points appropriate for this release are derived, along with relations linking colour indices to stellar parameters. Reddening-free pseudo-colours and pseudo-magnitudes are also introduced. For late-type stars which are best suited for Galactic Archaeology, we show that SkyMapper+2MASS are able to deliver a precision better than 100K in effective temperatures (depending on the filters), ~0.2dex for metallicities above -2, and a reliable distinction between M-dwarfs and -giants. Together with astrometric and asteroseismic space mission, SkyMapper promises to be a treasure trove for stellar and Galactic studies.