The YMCA (Yes, Magellanic Clouds Again) survey: Probing the outer regions of the Magellanic system with VST^⋆

¹ INAF – Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Naples, Italy
² INAF – Osservatorio di Astrofisica e Scienza dello Spazio, Via Gobetti 93/3, 40129 Bologna, Italy
³ Physics Department, University of Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy
⁴ INFN – Largo Bruno Pontecorvo 3, 56127 Pisa, Italy
⁵ Leibniz-Institut für Astrophysik Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany

Received: 7 May 2024
Accepted: 8 July 2024

Abstract

Context. The Magellanic Clouds (MCs) are the Milky Way’s most massive dwarf satellites. As they also represent the closest pair of galaxies in an ongoing tidal interaction while simultaneously infalling into the Milky Way halo, they provide a unique opportunity to study in detail an ongoing three-body encounter.

Aims. We present the YMCA (Yes, Magellanic Clouds Again) survey: Probing the outer regions of the Magellanic system with VST, based on deep optical photometry carried out with the VLT Survey Telescope (VST).

Methods. The YMCA survey targeted 110 square degrees, in the g and i filters, in the periphery of both MCs, including a long strip in between the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC). The photometry of YMCA is sufficiently deep (50% complete down to g ≃ 23.5 − 24.0 mag) to allow for a detailed analysis of main-sequence stars in regions of the MCs that have remained relatively unexplored at these faint magnitudes.

Results. The resulting colour–magnitude diagrams reveal that the outskirts of the MCs are predominantly characterised by intermediate-age and old stellar populations, with limited or negligible evidence of recent star formation. The analysis of the age distribution of star clusters (SCs) within the surveyed area, both already known and newly discovered candidates, hints at a close fly-by between the LMC and SMC that occurred ≃2.5 − 3.0 Gyr ago, in agreement with previous results. We also report the discovery of candidate SCs with ages within the so-called age-gap, thus questioning its real existence.