Jessica Kellar, Dartmouth College

I discovered a number of isolated and compact sources of emission (“H-alpha dots”) in a narrow-band H-alpha survey.  These H-alpha dots could be (1) isolated extra-galactic HII regions associated with a nearby larger galaxy, (2) dwarf star-forming galaxies, or (3) background galaxies, where another strong emission-line such as [OIII]5007 has redshifted into the H-alpha filter.  Based on follow-up spectra taken at the MDM 2.4 meter telescope and HET, I determined that the H-alpha dots are a combination of nearby (z~0.01) dwarf star-forming galaxies and intermediate-redshift (mostly at z~0.3) starforming galaxies and AGN.  I will discuss the star-formation properties, environments, and metallicities of the dwarf galaxies.  The star-forming galaxies at z~0.3 are very metal-poor, which suggests that they may be recently formed.  I will discuss the insights this diverse sample of galaxies from the H-alpha dot survey can give us about galaxy evolution.