Title: Measuring sizes of distant faint galaxies

Abstract:
Using the great angular resolution of ALMA can be challenging for high-redshift galaxies, as the 
typical brightness is low.  We have developed a new stacking algorithm that acts directly on the 
visibilities. Using this method it is possible to detect emission from high-redshift galaxies on 
much longer baselines than otherwise, and measure the typical sizes of populations of galaxies 
that would be otherwise unavailable to ALMA.

I will present results from stacking galaxies in the ALESS (230 GHz survey in ECDF-S) and and 
the deep 1.4 GHz VLA map of the field.  We have selected galaxies around z~2 using near 
infrared photometry (ERO, DRG, and sBzK). We find that the typical sizes of these galaxies are 
large (~1 arcsec) compared to SMGs which are typically more compact.