The Star Formation in Radio Survey: Jansky Very Large Array 33 GHz
  Observations of Nearby Galaxy Nuclei and Extranuclear Star-Forming Regions
  We present 33 GHz imaging for 112 pointings towards galaxy nuclei and
extranuclear star-forming regions at $\approx$2" resolution using the Karl G.
Jansky Very Large Array (VLA) as part of the Star Formation in Radio Survey. A
comparison with 33 GHz Robert C. Byrd Green Bank Telescope single-dish
observations indicates that the interferometric VLA observations recover
$78\pm4 %$ of the total flux density over 25" regions ($\approx$ kpc-scales)
among all fields. On these scales, the emission being resolved out is most
likely diffuse non-thermal synchrotron emission. Consequently, on the
$\approx30-300$ pc scales sampled by our VLA observations, the bulk of the 33
GHz emission is recovered and primarily powered by free-free emission from
discrete HII regions, making it an excellent tracer of massive star formation.
Of the 225 discrete regions used for aperture photometry, 162 are extranuclear
(i.e., having galactocentric radii $r_{\rm G} \geq 250$ pc) and detected at
$>3\sigma$ significance at 33 GHz and in H$\alpha$. Assuming a typical 33 GHz
thermal fraction of 90 %, the ratio of optically-thin 33 GHz-to-uncorrected
H$\alpha$ star formation rates indicate a median extinction value on
$\approx30-300$ pc scales of $A_{\rm H\alpha} \approx 1.26\pm0.09$ mag with an
associated median absolute deviation of 0.87 mag. We find that 10 % of these
sources are "highly embedded" (i.e., $A_{\rm H\alpha}\gtrsim3.3$ mag),
suggesting that on average HII regions remain embedded for $\lesssim1$ Myr.
Finally, we find the median 33 GHz continuum-to-H$\alpha$ line flux ratio to be
statistically larger within $r_{\rm G}<250$ pc relative the outer-disk regions
by a factor of $1.82\pm0.39$, while the ratio of 33 GHz-to-24 $\mu$m flux
densities are lower by a factor of $0.45\pm0.08$, which may suggest increased
extinction in the central regions.
