E+A Galaxies are post-starburst galaxies whom rapidly quench all star formation after about 1 Gyr; the reason yet to be determined. By the time we are able to identify them, all O and B-type stars have died out, leaving behind an A-type population of stars to dominate the light of the galaxy, giving them their signature golden colour, and placing the system in the green valley range of evolution space. Throughout the last 6 years, I have developed a refined by-eye classification system for this galaxy type that focuses on:

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• A very specific continuum shape, noting a bluer-than-usual continuum.

• Dn4000 ratio > 1.5 to indicate an older stellar population, not dominated by hot, young stars.

• Strong Balmer absorption lines to indicate a recent and substantial starburst. 

• A lack of Hα emission, and low to no [O II] emission to indicate that star formation has now ended.

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Once a candidate sample is curated, we use the IFS capabilites of MaNGA to investiagte the spatially resolved entirety of the galaxy to prove E+Aness throughout the entirety of the system. to This carefully curated and confirmed set of E+A galaxies can serve as the basis of a series of investigations of

galaxy evolution-- in particular, studies of what may be

the last stage of transition between actively star-forming

and fully quenched galaxies.

 

See Greene et al., 2021 for information about this process.