Starburst galaxies in the COSMOS field: clumpy star-formation at
  redshift 0 < z < 0.5
  At high redshift, starburst galaxies present irregular morphologies, with
10-20\%\ of their star formation occurring in giant clumps. These clumpy
galaxies are considered to be the progenitors of local disk galaxies. To
understand the properties of starbursts at intermediate and low redshift, it is
fundamental to track their evolution and possible link with the systems at
higher $z$. We present an extensive, systematic, and multi-band search and
analysis of the starburst galaxies at redshift ($0 < z < 0.5$) in the COSMOS
field, as well as detailed characteristics of their star-forming clumps by
using Hubble Space Telescope/Advance Camera for Surveys (HST/ACS) images. Their
principal properties, sizes, masses, and star formation rates are provided. The
individual star-forming knots in our sample follow the same L(H$\alpha$) vs.
size scaling relation than local giant HII regions (Fuentes-Masip et al. 2000).
However, they slightly differ from the one provided using samples at high
redshift. This result highlights the importance of spatially resolving the
star-forming regions for this kind of study. Star-forming clumps in the central
regions of Mknots galaxies are more massive, and present higher star formation
rates, than those in the outskirts. This trend is smeared when we consider
either the mass surface density or surface star formation rate. Sknot galaxies
do show properties similar to both dwarf elliptical and irregulars in the
surface brightness ($\mu$) versus M$_{host}$ diagram in the $B-$band (Amor\'in
et al. 2012), and to spheroidals and ellipticals in the $\mu$ versus M$_{host}$
diagram in the $V-$band (Kormendy \&\ Bender 2012). Sknot galaxies might be
transitional phases of the BCD class, with their properties consistent with
spheroidal like, but blue structures.
