We present a catalog of 142 dark galaxy candidates in a region covered by theArecibo Legacy Fast ALFA (ALFALFA) survey. We start with 344 ALFALFA HI sourceswithout optical counterparts and remove those that do not seem to have darkgalaxy origin. To do that, we first eliminate 83 sources that are known HIclouds probably formed from tidal interactions between galaxies and 13 sourcesthat have optical counterparts. We then remove 56 sources located near other HIsources, which are likely to be HI clouds. We further exclude 10 sources thathave nearby HI sources within the ALFALFA beam and 40 sources potentiallyassociated with nearby galaxies. We perform visual inspection of optical imagesfrom DESI Legacy Imaging Survey with an $r$-band surface brightness limit of$\sim 28.5 \rm \ mag\ arcsec^{-2}$ as well as NUV images from GALEX to confirmthe absence of stellar emission. We additionally inspect infrared images fromWISE and AKARI for dust emission. As a result, we identify 142 dark galaxycandidates and analyze their physical properties by comparing with luminousgalaxies. We find that the dark galaxy candidates generally have smallerdynamical masses, higher HI-to-dynamical mass ratios, and are located in lessdense regions when compared to luminous galaxies, which is consistent withresults from cosmological simulations. This sample provides an importanttestbed for studying the role of dark matter in galaxy formation and evolution.

Together optical/near infrared integral field spectroscopy and resolvedsub-millimetre interferometry data have mapped the ionised and molecular gasmotions in nearly one thousand galaxies at redshifts $z>0.5$. While thesemeasurements have revealed a number of key properties about the evolution ofdisc structure and kinematics, heterogenous techniques and samples have led todisparate findings - especially when comparing different dynamical tracers(e.g., H$\alpha$, [C$\scriptstyle\rm~II$], CO). In this paper we present aliterature compilation of 237 disc galaxies with measurements of velocitydispersion and rotational velocity between $z=0.5-8$, a subset of 63 galaxieshave measurements of molecular gas fractions. We explore the connection betweendisc velocity dispersion measurements over 8 Gyrs as traced by multiple phaseswith the expectations from Toomre stability models. When sample properties aretaken into account (e.g., stellar mass, tracer) there is little evolution indisc dispersions between $z\sim1.5-8$, consistent with expectations from modelassumptions. We find ionised gas dispersions are higher by $\sim2\times$ frommolecular gas dispersions at a fixed gas mass. These results are sensitive tothe molecular gas tracer with results from [C$\scriptstyle\rm~II$] showingmixed behaviour indicative of its multi-phase origin. The[C$\scriptstyle\rm~II$] kinematics can be reconciled with molecular and ionisedgas tracers when star-formation rates are taken into account.