The Araucaria Project: Deep near-infrared photometric maps of Local and Sculptor Group galaxies. I. Carina, Fornax, Sculptor

TL;DR

This paper provides deep near-infrared photometric maps of three Local Group dwarf spheroidal galaxies, offering a comprehensive database of stellar magnitudes, positions, and properties for community use, surpassing existing surveys in uniqueness.

Contribution

It presents a new, detailed near-infrared photometric database for Fornax, Carina, and Sculptor galaxies, expanding the data available for these galaxies beyond previous uses.

Findings

Photometry reaches about 22 mag at 5σ level.

Database is unique due to limited overlap with other surveys.

Provides high-quality, comprehensive stellar data for community use.

Abstract

Deep near-infrared $J$- and $K$-band photometry of three Local Group dwarf spheroidal galaxies: Fornax, Carina, and Sculptor, is made available for the community. Until now, these data have only been used by the Araucaria Project to determine distances using the tip of the red giant and RR Lyrae stars. Now, we present the entire data collection in a form of a database, consisting of accurate $J$- and $K$-band magnitudes, sky coordinates, ellipticity measurements, and timestamps of observations, complemented by stars' loci in their reference images. Depth of our photometry reaches about 22 mag at 5$\sigma$ level, and is comparable to NIR surveys, like the UKIRT Infrared Deep Sky Survey (UKIDSS) or the VISTA Hemisphere Survey (VHS). Small overlap with VHS and no overlap with UKIDSS makes our database a unique source of quality photometry.