The MAGellanic Inter-Cloud project (MAGIC) I: Evidence for intermediate-age stellar populations in between the Magellanic Clouds

TL;DR

This study provides the first quantitative evidence of intermediate-age and old stellar populations in the inter-Cloud region between the Magellanic Clouds, suggesting tidal stripping from the SMC, based on observations and synthetic CMD analysis.

Contribution

The paper presents the first detection and quantification of intermediate-age and old stars in the Magellanic Bridge region using new observational data and synthetic CMD techniques.

Findings

Intermediate-age stars constitute about 28% of the stellar population in the inter-Cloud region.

Presence of these stars is unique to the inter-Cloud region and not observed in similar-distance fields away from the LMC.

Results support the hypothesis that some stars in the Bridge may have been tidally stripped from the SMC.

Abstract

The origin of the gas in between the Magellanic Clouds (MCs) -- known as the `Magellanic Bridge' (MB) -- is puzzling. Numerical simulations suggest that the MB formed from tidally stripped gas and stars in a recent interaction between the MCs. However, the apparent lack of stripped intermediate- or old-age stars associated with the MB is at odds with this picture. In this paper, we present the first results from the MAGellanic Inter-Cloud program (MAGIC) aimed at probing the stellar populations in the inter-cloud region. We present observations of the stellar populations in two large fields located in between the Large and Small Magellanic Clouds (LMC/SMC), secured using the WFI camera on the 2.2 m telescope in La Silla. Using a synthetic color-magnitude diagram (CMD) technique, we present the first quantitative evidence for the presence of intermediate-age and old stars in the inter-Cloud region. The intermediate-age stars -- that make up ~28% of all stars in the region -- are not present in fields at a similar distance from the SMC in a direction pointing away from the LMC. This provides potential evidence that these intermediate-age stars could have been tidally stripped from the SMC. However, spectroscopic studies will be needed to confirm or rule out the tidal origin for the inter-Cloud gas and stars.