Vihang Mehta (Caltech/IPAC): "Extreme Emission Line Galaxies in the Local Universe"


Observations of high-redshift galaxies have shown them to have extremely bright emission lines with equivalent widths much larger than the local star forming galaxy population. Extreme emission line galaxies (EELGs) in the local universe, such as the Green Pea (GP) and Blue Compact Dwarf (BCD) galaxies, are likely analogs of these early galaxies. Albeit rare, they serve as a more accessible means to study the physical properties of the earliest galaxies. In this talk, I will present results from multiple recent imaging and spectroscopic observation campaigns to study these EELGs in the local universe. High-resolution HST imaging of known GPs has revealed the presence of stellar clusters and also potentially hints at an older underlying stellar population. Furthermore, we have assembled a statistically significant sample of BCDs from the Dark Energy Survey (DES) as well as targeted a subset with ground-based spectroscopic follow-up, which has provided key insights about their metallicity properties. Lastly, recent narrow+broad-band HST imaging of Pox 186, which is one of the closest and well-studied BCDs, has enabled a resolved analysis of its stellar and ISM properties, and I will discuss the resultant implications about its physical structure.