UVIT view of dwarf irregular galaxy IC 2574 : Is the star formation
  triggered due to expanding H$~$I shells?
  Star forming dwarf galaxies in the local volume are diverse and are ideal
test beds to understand details of star formation in a variety of environments.
Here, we present a deep FUV imaging study of a nearby dwarf irregular galaxy IC
2574 using the Ultraviolet Imaging Telescope (UVIT). We identified 419 FUV
bright regions with radii between 15 - 285 pc in the galaxy and found that
28.6\% of them to be located in H~I shells, 12.6\% inside holes and 60.1\% to
be away from the holes. The H~I column density is found to be more than
$10^{21} cm^{-2}$ for 82.3\% of the identified regions. 30 out of the 48 H~I
holes show triggered star formation in their shells while 16 holes do not show
any related FUV emission. Cross-matching with H$\alpha$ emission, we found that
23 holes have both FUV and H$\alpha$ emission in their shells signifying very
recent trigger. Therefore, star formation in the galaxy has been partly
triggered due to the expanding H~I holes whereas in majority of the sites it is
driven by other mechanisms. Irrespective of the location, larger star forming
complexes were found to have multiple sub-structures. We report two resolved
components for the remnant cluster of the super giant shell and estimated their
masses. The star formation rate of IC 2574 is found to be 0.57 $M_{\odot}$/yr,
which is slightly higher compared to the average value of other nearby dwarf
irregular galaxies.
