DYNAMO-HST Survey: Clumps in Nearby Massive Turbulent Disks and the
  Effects of Clump Clustering on Kiloparsec Scale Measurements of Clumps
  We present $\sim$100 pc resolution Hubble Space Telescope H$\alpha$ images of
10 galaxies from the DYnamics of Newly-Assembled Massive Objects (DYNAMO)
survey of low-$z$ turbulent disk galaxies, and use these to undertake the first
detailed systematic study of the effects of resolution and clump clustering on
observations of clumps in turbulent disks. In the DYNAMO-{\em HST} sample we
measure clump diameters spanning the range $d_{clump} \sim 100-800$~pc, and
individual clump star formation rates as high as $\sim5$~M$_{\odot}$~yr$^{-1}$.
DYNAMO clumps have very high SFR surface densities, $\Sigma_{SFR}\sim
15$~M$_{\odot}$~yr$^{-1}$~kpc$^{-2}$, $\sim100\times$ higher than in H{\sc ii}
regions of nearby spirals. Indeed, SFR surface density provides a simple
dividing line between massive star forming clumps and local star forming
regions, where massive star forming clumps have $\Sigma_{SFR}>
0.5$~M$_{\odot}$~yr$^{-1}$~kpc$^{-2}$. When degraded to match the observations
of galaxies in $z\sim 1-3$ surveys, DYNAMO galaxies are similar in morphology
and measured clump properties to clumpy galaxies observed in the high-$z$
Universe. Emission peaks in the simulated high-redshift maps typically
correspond to multiple clumps in full resolution images. This clustering of
clumps systematically increases the apparent size and SFR of clumps in 1~kpc
resolution maps, and decreases the measured SFR surface density of clumps by as
much as a factor of 20$\times$. From these results we can infer that clump
clustering is likely to strongly effect the measured properties of clumps in
high-$z$ galaxies, which commonly have kiloparsec scale resolution.
