Structured star formation in the Magellanic inter-Cloud region

Abstract

We use a new contiguous imaging survey conducted using the Dark Energy Camera to investigate the distribution and properties of young stellar populations in the Magellanic inter-Cloud region. These young stars are strongly spatially clustered, forming a narrow chain of low-mass associations that trace the densest HI gas in the Magellanic Bridge and extend, in projection, from the SMC to the outer disk of the LMC. The associations in our survey footprint have ages $\lesssim 30$ Myr, masses in the range $\sim 100-1200{\mathrm{M}}_{\odot }$, and very diffuse structures with half-light radii of up to $\sim 100$ pc. The two most populous are strongly elliptical, and aligned to $\approx 10^{\mathrm{o}}$ with the axis joining the centres of the LMC and SMC. These observations strongly suggest that the young inter-Cloud populations formed in situ, likely due to the compression of gas stripped during the most recent close LMC-SMC encounter. The associations lie at distances intermediate between the two Clouds, and we find no evidence for a substantial distance gradient across the imaged area. Finally, we identify a vast shell of young stars surrounding a central association, that is spatially coincident with a low column density bubble in the HI distribution. The properties of this structure are consistent with a scenario where stellar winds and supernova explosions from massive stars in the central cluster swept up the ambient gas into a shell, triggering a new burst of star formation. This is a prime location for studying stellar feedback in a relatively isolated environment.

Accepted for publication in MNRAS

References in corpus (24)

• The Gaia mission
• Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
• Gaia Data Release 1: Astrometry - one billion positions, two million proper motions and parallaxes
• Are the Magellanic Clouds on their First Passage about the Milky Way?
• Beasts of the Southern Wild: Discovery of nine Ultra Faint satellites in the vicinity of the Magellanic Clouds
• Is the SMC Bound to the LMC? The HST Proper Motion of the SMC
• The Origin of the Magellanic Stream and Its Leading Arm
• The Blanco Cosmology Survey: Data Acquisition, Processing, Calibration, Quality Diagnostics and Data Release
• The VLT-FLAMES survey of massive stars: Evolution of surface N abundances and effective temperature scales in the Galaxy and Magellanic Clouds
• Clustering of Local Group distances: publication bias or correlated measurements? I. The Large Magellanic Cloud
• Black holes and core expansion in massive star clusters
• HI holes and high-velocity clouds in the spiral galaxy NGC 6946
• GASS: The Parkes Galactic All-Sky Survey. Update: improved correction for instrumental effects and new data release
• The PAndAS view of the Andromeda satellite system - II. Detailed properties of 23 M31 dwarf spheroidal galaxies
• Clustering of Local Group distances: publication bias or correlated measurements? III. The Small Magellanic Cloud
• The outer halo globular cluster system of M31 - I. The final PAndAS catalogue
• Clouds, Streams and Bridges. Redrawing the blueprint of the Magellanic System with Gaia DR1
• ACS photometry of extended, luminous globular clusters in the outskirts of M31
• Discovery of a Faint Outer Halo Milky Way Star Cluster in the Southern Sky
• Scl-dE1 GC1: An Extended Globular Cluster in a Low-Luminosity Dwarf Elliptical Galaxy
• Metallicity and Physical Conditions in the Magellanic Bridge
• The Clouds are breaking: tracing the Magellanic system with Gaia DR1 Mira variables
• OGLE-ing the Magellanic System: Stellar populations in the Magellanic Bridge
• The iron abundance of the Magellanic Bridge