In this work, we investigate the strength and impact of ionised gas outflowswithin $z \sim 0.04$ MaNGA galaxies. We find evidence for outflows in 322galaxies ($12\%$ of the analysed line-emitting sample), 185 of which showevidence for AGN activity. Most outflows are centrally concentrated with aspatial extent that scales sublinearly with $R_{\rm e}$. The incidence ofoutflows is enhanced at higher masses, central surface densities and deepergravitational potentials, as well as at higher SFR and AGN luminosity. Wequantify strong correlations between mass outflow rates and the mechanicaldrivers of the outflow of the form $\dot{M}_{\rm out} \propto \rm SFR^{0.97}$and $\dot{M}_{\rm out} \propto L_{\rm AGN}^{0.55}$. We derive a master scalingrelation describing the mass outflow rate of ionised gas as a function of$M_{\star}$, SFR, $R_{\rm e}$ and $L_{\rm AGN}$. Most of the observed winds areanticipated to act as galactic fountains, with the fraction of galaxies withescaping winds increasing with decreasing potential well depth. We furtherinvestigate the physical properties of the outflowing gas finding evidence forenhanced attenuation in the outflow, possibly due to metal-enriched winds, andhigher excitation compared to the gas in the galactic disk. Given that themajority of previous studies have focused on more extreme systems with higherSFRs and/or more luminous AGN, our study provides a unique view of thenon-gravitational gaseous motions within `typical' galaxies in the low-redshiftUniverse, where low-luminosity AGN and star formation contribute jointly to theobserved outflow phenomenology.

In early type galaxies, externally accreted gas is thought to be the mainsource of gas replenishment at late times. We use MUSE integral fieldspectroscopy data to study the active S0 galaxy NGC 5077, known to havedisturbed dynamics, indicative of a past external interaction. We confirm thepresence of a stellar kinematically distinct core with a diameter of 2.8 kpc,counter-rotating with respect to the main stellar body of the galaxy. We findthat the counter-rotating core consists of an old stellar population, notsignificantly different from the rest of the galaxy. The ionised gas isstrongly warped and extends out to 6.5 kpc in the polar direction and in afilamentary structure. The gas dynamics is complex, with significant changes inthe position angle as a function of radius. The ionised gas line ratios areconsistent with LINER excitation by the AGN both in the nucleus and atkiloparsec scales. We discover a nuclear outflow with projected velocity V ~400 km/s, consistent with a hollow outflow cone intersecting the plan of thesky. The properties of the misaligned gas match predictions from numericalsimulations of misaligned gas infall after a gas-rich merger. The warp andchange in the gas orientation as a function of radius are consistent with gasrelaxation due to stellar torques, that are stronger at small radii where thegas aligns faster than in the outer regions, driving gas to the nucleus. Thestellar and gas dynamics indicate that NGC 5077 has had at least two externalinteractions, one that resulted in the formation of the counter-rotating corefollowed by late time external gas accretion. NGC 5077 illustrates theimportance of external interactions in the replenishment of the galaxy gasreservoir and the nuclear gas content available for black hole fuelling.

We present spectroscopic observations of superthin galaxies. Superthingalaxies have the thinnest stellar disks among disk galaxies. A sample of 138superthins was observed in visible light with the 3.5 m telescope at ApachePoint Observatory in New Mexico to obtain the rotation curves of the ionizedgas in the galaxies. The sample represents the largest survey of superthingalaxies so far and provides a database to investigate the kinematic anddynamic properties of this special type of extragalactic objects. Here wepresent the rotation curves of our sample objects.

Nearby, low-metallicity dwarf starburst galaxies hosting active galacticnuclei (AGNs) offer the best local analogs to study the early evolution ofgalaxies and their supermassive black holes (BHs). Here we present a detailedmulti-wavelength investigation of star formation and BH activity in thelow-metallicity dwarf-dwarf galaxy merger Mrk 709. Using Hubble Space TelescopeH$\alpha$ and continuum imaging combined with Keck spectroscopy, we determinethat the two dwarf galaxies are likely in the early stages of a merger (i.e.,their first pass) and discover a spectacular $\sim 10$ kpc-long string of youngmassive star clusters ($t \lesssim 10$ Myr; $M_\star \gtrsim 10^5~M_\odot$)between the galaxies triggered by the interaction. We find that the southerngalaxy, Mrk 709 S, is undergoing a clumpy mode of star formation resemblingthat seen in high-redshift galaxies, with multiple young clusters/clumps havingstellar masses between $10^7$ and $10^8~M_\odot$. Furthermore, we presentadditional evidence for a low-luminosity AGN in Mrk 709 S (first identified byReines et al. 2014 (arXiv:1405.0278) using radio and X-ray observations),including the detection of the coronal [Fe X] optical emission line. The workpresented here provides a unique glimpse into processes key to hierarchicalgalaxy formation and BH growth in the early Universe.

The low-mass low-surface brightness (LSB) disc galaxy Arakelian 18 (Ark 18)resides in the Eridanus void and because of its isolation represents an idealcase to study the formation and evolution mechanisms of such a galaxy type. Itscomplex structure consists of an extended blue LSB disc and a bright centralelliptically-shaped part hosting a massive off-centered star-forming clump. Wepresent the in-depth study of Ark 18 based on observations with the SCORPIO-2long-slit spectrograph and a scanning Fabry-Perot interferometer at the Russian6-m telescope complemented by archival multi-wavelength images and SDSSspectra. Ark 18 appears to be a dark matter dominated gas-rich galaxy without aradial metallicity gradient. The observed velocity field of the ionised gas iswell described by two circularly rotating components moderately inclined withrespect to each other and a possible warp in the outer disc. We estimated theage of young stellar population in the galaxy centre to be ~140 Myr, while thebrightest star-forming clump appears to be much younger. We conclude that theLSB disc is likely the result of a dwarf-dwarf merger with a stellar mass ratioof the components at least ~5:1 that occurred earlier than 300 Myr ago. Thebrightest star forming clump was likely formed later by accretion of a gascloud.

We address the puzzling observational indications for very "cold" galacticdiscs at redshifts $z \gtrsim 3$, an epoch when discs are expected to be highlyperturbed. Using a high-resolution cosmological zoom-in simulation, we identifysuch a cold disc at $z\sim 3.5$, with a rotation velocity to velocitydispersion ratio of $v_\phi/\sigma_r \simeq 5$ for the total gas. It forms as aresult of a period of intense accretion of co-planar, co-rotating gas via coldcosmic-web streams. This thin disc survives for $\sim 5$ orbital periods, afterwhich it is disrupted by mergers and counter-rotating streams, longer butconsistent with our estimate that a galaxy of this mass($M_\star\sim10^{10}\mathrm{M_\odot}$) typically survives merger-driven spinflips for $\sim 2-3$ orbital periods. We find that $v_\phi/\sigma_r$ is highlysensitive to the tracer used to perform the kinematic analysis. While it is$v_\phi/\sigma_r \simeq 3.5$ for atomic HI gas, it is $v_\phi/\sigma_r \simeq8$ for molecular CO and H$_2$. This reflects the confinement of molecular gasto cold, dense clouds that reside near the disc mid-plane, while the atomic gasis spread into a turbulent and more extended thicker disc.