Structured star formation in the Magellanic inter-Cloud region
  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 $\sim 100-1200\,{\rm M}_\odot$, and
very diffuse structures with half-light radii of up to $\sim 100$ pc. The two
most populous are strongly elliptical, and aligned to $\approx 10^{{\rm o}}$
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.
