We present results from a survey of the internal kinematics of 49star-forming galaxies at z$\,\sim\,$2 in the CANDELS fields with theKeck/MOSFIRE spectrograph (SIGMA, Survey in the near-Infrared of Galaxies withMultiple position Angles). Kinematics (rotation velocity $V_{rot}$ andintegrated gas velocity dispersion $\sigma_g$) are measured from nebularemission lines which trace the hot ionized gas surrounding star-formingregions. We find that by z$\,\sim\,$2, massive star-forming galaxies($\log\,M_*/M_{\odot}\gtrsim10.2$) have assembled primitive disks: theirkinematics are dominated by rotation, they are consistent with a marginallystable disk model, and they form a Tully-Fisher relation. These massivegalaxies have values of $V_{rot}/\sigma_g$ which are factors of 2-5 lower thanlocal well-ordered galaxies at similar masses. Such results are consistent withfindings by other studies. We find that low mass galaxies($\log\,M_*/M_{\odot}\lesssim10.2$) at this epoch are still in the early stagesof disk assembly: their kinematics are often supported by gas velocitydispersion and they fall from the Tully-Fisher relation to significantly lowvalues of $V_{rot}$. This "kinematic downsizing" implies that the process(es)responsible for disrupting disks at z$\,\sim\,$2 have a stronger effect and/orare more active in low mass systems. In conclusion, we find that the period ofrapid stellar mass growth at z$\,\sim\,$2 is coincident with the nascentassembly of low mass disks and the assembly and settling of high mass disks.

We have developed an observing program using deep, multiband imaging to probethe chaotic regions of tidal tails in search of an underlying stellarpopulation, using NGC 3256's 400 Myr twin tidal tails as a case study. Thesetails have different colours of $u - g = 1.05 \pm 0.07$ and $r - i = 0.13 \pm0.07$ for NGC 3256W, and $u - g = 1.26 \pm 0.07$ and $r - i = 0.26 \pm 0.07$for NGC 3256E, indicating different stellar populations. These colourscorrespond to simple stellar population ages of $288^{+11}_{-54}$ Myr and$841^{+125}_{-157}$ Myr for NGC 3256W and NGC 3256E, respectively, suggestingNGC 3256W's diffuse light is dominated by stars formed after the interaction,while light in NGC 3256E is primarily from stars that originated in the hostgalaxy. Using a mixed stellar population model, we break our diffuse light intotwo populations: one at 10 Gyr, representing stars pulled from the hostgalaxies, and a younger component, whose age is determined by fitting the modelto the data. We find similar ages for the young populations of both tails,($195^{-13}_{+0}$ and $170^{-70}_{+44}$ Myr for NGC 3256W and NGC 3256E,respectively), but a larger percentage of mass in the 10 Gyr population for NGC3256E ($98^{+1}_{-3}\%$ vs $90^{+5}_{-6}\%$). Additionally, we detect 31 starcluster candidates in NGC 3256W and 19 in NGC 2356E, with median ages of 141Myr and 91 Myr, respectively. NGC 3256E contains several young (< 10 Myr), lowmass objects with strong nebular emission, indicating a small, recent burst ofstar formation.

We study the influence of environment on the structure of disc galaxies,using \texttt{IMFIT} to measure the g- and r-band structural parameters of thesurface-brightness profiles for $\sim$700 low-redshift (z$<$0.063) cluster andfield disc galaxies with intermediate stellar mass (0.8 $\times$ 10$^{10}$$M_{\odot}$ $<$ $M_{\star}$ $<$ 4 $\times$ 10$^{10}$ $M_{\odot}$) from theSloan Digital Sky Survey, DR7. Based on this measurement, we assign each galaxyto a surface-brightness profile type (Type I $\equiv$ single-exponential, TypeII $\equiv$ truncated, Type III $\equiv$ anti-truncated). In addition, wemeasure (g-r) restframe colour for disc regions separated by the break radius.Cluster disc galaxies (at the same stellar mass) have redder (g-r) colour by$\sim$0.2 mag than field galaxies. This reddening is slightly more pronouncedoutside the break radius. Cluster disc galaxies also show larger globalS\'ersic-indices and are more compact than field discs, both by $\sim$15\%.This change is connected to a flattening of the (outer) surface-brightnessprofile of Type I and - more significantly - of Type III galaxies by $\sim$8\%and $\sim$16\%, respectively, in the cluster environment compared to the field.We find fractions of Type I, II and III of (6$\pm$2)\%, (66$\pm$4)\% and(29$\pm$4)\% in the field and (15$_{-4}^{+7}$)\%, (56$\pm$7)\% and (29$\pm$7)\%in the cluster environment, respectively. We suggest that the larger abundanceof Type I galaxies in clusters (matched by a corresponding decrease in the TypeII fraction) could be the signature of a transition between Type II and Type Igalaxies produced/enhanced by environment-driven mechanisms.

We use new precision measurements of black hole masses from water megamaserdisks to investigate scaling relations between macroscopic galaxy propertiesand supermassive black hole (BH) mass. The megamaser-derived BH masses span10^6-10^8 M_sun, while all the galaxy properties that we examine (includingstellar mass, central mass density, central velocity dispersion) lie within anarrow range. Thus, no galaxy property correlates tightly with M_BH in ~L*spiral galaxies. Of them all, stellar velocity dispersion provides the tightestrelation, but at fixed sigma* the mean megamaser M_BH are offset by -0.6+/-0.1dex relative to early-type galaxies. Spiral galaxies with non-maser dynamicalBH masses do not show this offset. At low mass, we do not yet know the fulldistribution of BH mass at fixed galaxy property; the non-maser dynamicalmeasurements may miss the low-mass end of the BH distribution due to inabilityto resolve the spheres of influence and/or megamasers may preferentially occurin lower-mass BHs.