Description
Giant star-forming clumps (GSFCs) are areas of intensive star-formation that are commonly observed in high-redshift (z > 1) galaxies. Observations of low-redshift clumpy galaxy analogues are rare but the availability of wide-field galaxy survey data makes the detection of large clumpy galaxy samples much more feasible. We present a population of ~20,000 clumps in ~16,000 galaxies at redshifts z < 0.5, located in the XMM-LSS, E-COSMOS, ELAIS-N1 and DEEP2-3 fields observed by the Hyper Suprime-Cam Subaru Strategic Survey (HSC-SSP) and CFHT Large Area U-band Deep Survey (CLAUDS). The clump detections are the result of an improved version of our Faster R-CNN object detection framework (FRCNN) which uses 'Zoobot' as a 'backbone' feature extractor. For a small set of galaxies at z < 0.03, we were able to resolve the substructural morphologies of kpc-scale `clump complexes' into smaller clumps which would otherwise apear as a single clump in unresolved images. We measured the ugrizy-photometry and estimated the physical properties (stellar mass, age, dust extinction and star-formation rate) for each clump and clump complex in our sample by fitting the photometric data to stellar population models. The clumps show elevated star-formation rates and negative gradients in their ages and stellar masses as a function of galactocentric distance. For nearby galaxies we argue that the inward migration of star-forming clumps directly contributes to the central bulge formation of the host galaxy and that our observations support the small physical scales (~100 pc) of clumps resulting from simulation studies and observations of lensed galaxies.
