Star Formation in Isolated Dwarf Galaxies Hosting Tidal Debris:
  Extending the Dwarf-Dwarf Merger Sequence
  Like massive galaxies, dwarf galaxies are expected to undergo major mergers
with other dwarfs. However, the end state of these mergers and the role that
merging plays in regulating dwarf star formation is uncertain. Using imaging
from the Hyper Suprime-Cam Subaru Strategic program, we construct a sample of
dwarf-dwarf mergers and examine the star formation and host properties of the
merging systems. These galaxies are selected via an automated detection
algorithm from a sample of 6875 spectroscopically selected isolated dwarf
galaxies at $z<0.12$ and $\log(M_\star/M_\odot)<9.6$ from the Galaxy and Mass
Assembly (GAMA) and Sloan Digital Sky Survey (SDSS) spectroscopic campaigns. We
find a total tidal feature detection fraction of 3.29% (6.1% when considering
only galaxies at $z<0.05$). The tidal feature detection fraction rises strongly
as a function of star formation activity; 15%-20% of galaxies with extremely
high H$\alpha$ equivalent width (H$\alpha$ EW > 250 Angstrom) show signs of
tidal debris. Galaxies that host tidal debris are also systematically bluer
than the average galaxy at fixed stellar mass. These findings extend the
observed dwarf-dwarf merger sequence with a significant sample of dwarf
galaxies, indicating that star formation triggered in mergers between dwarf
galaxies continues after coalescence.
