I haven’t given up on this topic. Just a longer than expected break.
I found two other catalogs of candidate PSBs selected from SDSS spectroscopy. First are the “SPOGs” (Shocked POst-starburst Galaxies” of Alatalo et al. (2016), with the catalog retrieved from VizieR at J/ApJS/224/38/table2. These were selected to have strong emission lines with ratios consistent with shocks as the ionizing mechanism, while also having strong Balmer absorption indicating the presence of a large intermediate age stellar light contribution.
The second was the sample of Pattarakijwanich et al. (2016) retrieved from J/ApJ/833/19/table3. This work used more traditional post-starburst selection criteria although somewhat more relaxed than for example Goto. Together these added 19 galaxies to the sample — 14 SPOGs and 5 from Patta… Together these, along with the Melnick and dePropris sample added about 1000 binned spectra to the sample.
I’m not going to say much about them for now. SDSS thumbnails are below. One thing I note is that a fairly large fraction of these appear to be normal star forming disk galaxies. Most of those, I suspect, are SPOGs. Of course since they were selected from 3″ SDSS spectra it’s entirely possible these galaxies are centrally quenched due to some feedback mechanism.
I’m still thinking about how to quantify “post-starburstiness.” Perhaps something like the stellar mass formed in a time interval like 1.1 – 0.1 Gyr.
