STEP: The VST survey of the SMC and the Magellanic Bridge. I. Overview and first results

TL;DR

The STEP survey uses VST imaging to study the Small Magellanic Cloud, its connecting Bridge, and part of the Magellanic Stream, providing detailed stellar data and initial analysis of selected regions and clusters.

Contribution

This paper introduces the STEP survey's strategy, techniques, and initial results, including detailed analysis of specific stellar clusters in the SMC region.

Findings

Resolved stars down to faint magnitudes in surveyed regions.

Initial analysis of stellar clusters IC 1624 and NGC 419.

Described survey methodology and early data products.

Abstract

STEP (the SMC in Time: Evolution of a Prototype interacting late-type dwarf galaxy) is a Guaranteed Time Observation survey being performed at the VST (the ESO VLT Survey Telescope). STEP will image an area of 74 deg$^2$ covering the main body of the Small Magellanic Cloud (32 deg$^2$), the Bridge that connects it to the Large Magellanic Cloud (30 deg$^2$) and a small part of the Magellanic Stream (2 deg$^2$). Our $g,r,i,H_{\alpha}$ photometry is able to resolve individual stars down to magnitudes well below the main-sequence turnoff of the oldest populations. In this first paper we describe the observing strategy, the photometric techniques, and the upcoming data products of the survey. We also present preliminary results for the first two fields for which data acquisition is completed, including some detailed analysis of the two stellar clusters IC\,1624 and NGC\,419.