Properties of the brightest young stellar clumps in extremely lensed galaxies at redshifts 4 to 5

Understand

We study the populations of stellar clumps in three high-redshift galaxies, at z=4.92, 4.88 and 4.03, gravitationally lensed by the foreground galaxy clusters MS1358, RCS0224 and MACS0940, respectively.

• The lensed galaxies consist of multiple counter-images with large magnifications, mostly above $\rm \mu>5$ and in some cases reaching $\rm \mu>20$.
• We use rest-frame UV observations from the HST to extract and analyse their clump populations, counting 10, 3 and 11 unique sources, respectively.
• Most of the clumps have derived effective radii in the range $\rm R_{eff}=10-100$ pc, with the smallest one down to 6 pc, i.e.