A B S T R A C TWe present near-infrared 2.1-m continuum and Br and 1-0 S(1) line images of three blue compact dwarf galaxies: II Zw 40, NGC 5253 and He 2-10. Comparison of the morphologies of the emission-line regions and continuum together with the line ratios shows that in these cases the starbursts are typified by strongly peaked Br and weak diffuse H 2 emission, indicating the presence of one or more compact nuclei, and also tidal tails. We consider the possible origins of the H 2 emission, and conclude that shock excitation in cloud collisions, and hence dynamical processes such as interactions or mergers, is important. By comparing models of the equivalent width of Br to other age constraints from the literature we show that the star formation must have occurred not only recently but in a short-duration burst. The current centres of star formation in all three galaxies are of a similar age but, whereas the hotspots in He 2-10 are coeval, we find phase differences between those in NGC 5253. We compare the masses and sizes of the star formation sites to those of present-day globular clusters.Blue compact dwarf galaxies 45 © 1998 RAS, MNRAS 295, 43-54 Table 1. Observed fluxes for II Zw 40.Errors are typically 2 per cent for Br , 5 per cent for 1-0S(1) and 5-10 per cent for the continuum.Blue compact dwarf galaxies 47 © 1998 RAS, MNRAS 295, 43-54 Figure 2. NGC 5253: left: 2.1 m continuum (contours at 0.4-1.8 mJy arcsec 22 ); centre: Br (contours at 0.7, 1.3, 2.0 and 4.4-19.8 10 218 W m 22 arcsec 22 ); right: 1-0 S(1) (contours at 1.7, 2.4 and 3.1 10 219 W m 22 arcsec 22 ). The crosses indicate the positions of the three continuum peaks.

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We report on our combined analysis of HST, VLT/MUSE, VLT/SINFONI, and ALMA observations of the local Seyfert 2 galaxy, NGC 5728 to investigate in detail the feeding and feedback of the AGN. The datasets simultaneously probe the morphology, excitation, and kinematics of the stars, ionized gas, and molecular gas over a large range of spatial scales (10 pc-10 kpc). NGC 5728 contains a large stellar bar which is driving gas along prominent dust lanes to the inner 1 kpc where the gas settles into a circumnuclear ring. The ring is strongly star forming and contains a substantial population of young stars as indicated by the lowered stellar velocity dispersion and gas excitation consistent with HII regions. We model the kinematics of the ring using the velocity field of the CO (2-1) emission and stars and find it is consistent with a rotating disk. The outer regions of the disk, where the dust lanes meet the ring, show signatures of inflow at a rate of 1 M yr −1 . Inside the ring, we observe three molecular gas components corresponding to the circular rotation of the outer ring, a warped disk, and the nuclear stellar bar. The AGN is driving an ionized gas outflow that reaches a radius of 250 pc with a mass outflow rate of 0.08 M yr −1 consistent with its luminosity and scaling relations from previous studies. While we observe distinct holes in CO emission which could be signs of molecular gas removal, we find that largely the AGN is not disrupting the structure of the circumnuclear region.

Using integral field spectroscopy we investigate the kinematic properties of 35 massive centrally-dense and compact star-forming galaxies (log M * [M ] = 11.1, log (Σ 1kpc [M kpc −2 ]) > 9.5, log (M * /r 1.5 e [M kpc −1.5 ]) > 10.3) at z ∼ 0.7 − 3.7 within the KMOS 3D survey. We spatially resolve 23 compact star-forming galaxies (SFGs) and find that the majority are dominated by rotational motions with velocities ranging from 95 − 500 km s −1 . The range of rotation velocities is reflected in a similar range of integrated Hα linewidths, 75 − 400 km s −1 , consistent with the kinematic properties of mass-matched extended galaxies from the full KMOS 3D sample. The fraction of compact SFGs that are classified as 'rotation-dominated' or 'disk-like' also mirrors the fractions of the full KMOS 3D sample. We show that integrated line-of-sight gas velocity dispersions from KMOS 3D are best approximated by a linear combination of their rotation and turbulent velocities with a lesser but still significant contribution from galactic scale winds. The Hα exponential disk sizes of compact SFGs are on average 2.5 ± 0.2 kpc, 1 − 2× the continuum sizes, in agreement with previous work. The compact SFGs have a 1.4× higher AGN incidence than the full KMOS 3D sample at fixed stellar mass with average AGN fraction of 76%. Given their high and centrally concentrated stellar masses as well as stellar to dynamical mass ratios close to unity, the compact SFGs are likely to have low molecular gas fractions and to quench on a short time scale unless replenished with inflowing gas. The rotation in these compact systems suggests that their direct descendants are rotating passive galaxies.