We study the feeding and feedback of the nucleus of M51 by considering gravitational torques, responsible for gas inflow, in relation to the local distribution of dense gas.

We summarize the results presented in Krause et al. (2012a, K12) on the impact of supernova-driven shells and dark-remnant accretion on gas expulsion in globular cluster infancy.

Lyman-α emitting (LAE) galaxies observed at intermediate to high redshift have the correct size, mass, star formation rate, metallicity, and space density to have been the formation sites of metal-poor globular clusters. LAEs are typically small galaxies with transient starbursts. They should accrete onto spiral and elliptical galaxies over time, delivering metal-poor clusters into the larger galaxies' halos as they themselves get dispersed by tidal forces. The galaxy WLM is a good example of a dwarf remnant from a very early starburst that contains a metal-poor globular cluster but failed to get incorporated into the Milky Way or M31 because of its remote location in the local group.

We present two-dimensional (2D) near-infrared spectra of the inner 300×300 pc2 of the Seyfert 2 galaxy NGC 5929 at a spatial resolution of ~20 pc obtained with the Gemini Near infrared Integral Field Spectrograph (NIFS). We present 2D maps for the emission line flux distributions and kinematics and report the discovery of a linear structure ~300 pc in extent and of ~50 pc in width oriented perpendicular to the radio jet, showing broadened emission-line profiles.

While over most of the field the emission-line profiles have full-widths-at-half-maximum (FWHM) of ~210 km/s, at a linear structure perpendicular do the radio jet the emission-line FWHMs are twice this value, and are due to two velocity components, one blueshifted and the other redshifted relative to the systemic velocity. We attribute these velocities to an outflow from the nucleus which is launched perpendicular to the radio jet. We reported the detection of this peculiar outflow in Riffel, Storchi-Bergmann & Riffel (2014a), where more details of the analysis can be found. Since, NGC 5929 has a Type 2 nucleus, this detection implies that: (1) both ionizing radiation and relativistic particles are escaping through holes in the torus perpendicular to the radio jet; and/or (2) the torus is also outflowing, as proposed by recent models of tori as winds from the outer parts of an accretion flow; or (3) the torus is absent in NGC 5929.

At other locations the gas kinematics is dominated by rotation in a disk, although some evidences of interaction of the radio jet with the emitting gas are seen as a broadening of the line profiles at the locations of the radio structures.

The flux distributions for the [P ii], [Fe ii], H i and H2 emission lines show that the line emission is more extended along the PA = 60/240^, extending to up to 1.5” to both sides of the nucleus, while to the perpendicular direction (PA = -30/150^) the emission is extended to 0.7” from the nucleus. The flux distributions of all emission lines show a good correlation with radio the radio structures, with the two peak of emission associated to the soutwestern and northeastern radio knots. Some differences are observed among distinct emission lines. While the [Fe ii] and H2 emission peak at the location of the soutwestern radio structure at 0.6” from the nucleus, the H i recombination lines present the their highest fluxes at the location of the northeastern radio hotspot at 0.5” from the nucleus. Another difference is that the H2 emission is less collimated than that for other lines, being more extended perpendicularly to the radio jet. A detailed analysis of the line emission and kinematics will be presented in Riffel, Storchi-Bergmann & Riffel (2014b).

Using the imaging Fourier transform spectrograph (FTS) SpIOMM we study 7 nearby spiral galaxies. The large database of spectra obtained around Hα and Hβ is ideal to study the star forming regions and warm ionized medium (WIM) with a high spatial resolution (∼ 50-150 pc).

Several dynamical scenarios have been proposed that can lead to prompt mass segregation on the crossing time scale of a young cluster. They generally rely on cool and/or clumpy initial conditions, and are most relevant to small systems. As a counterpoint, we present a novel dynamical mechanism that can operate in relatively large, homogeneous, cool or cold systems. This mechanism may be important in understanding the assembly of large mass-segregated clusters from smaller clumps.

We investigate the existence of a Kennicutt-Schmidt type relation between ΣSFR and Σgas, atomic in the HI dominated regions of nearby spirals and dwarf irregulars.

This is an overview of nuclear star cluster observations, covering their structure, stellar populations, kinematics and possible connection to black holes at the centers of galaxies.

This talk is an attempt to combine recent insights into the nature of the nuclear star clusters in galaxies of various morphologies into a coherent (albeit simplistic) picture for their formation, growth, and eventual destruction.

We found with ALMA 3D spectroscopy two bipolar molecular outflows in the luminous infrared galaxy NGC 3256. Each of the two merger nuclei has its own bipolar outflow.

Using data from the SAMI Galaxy Survey we measure azimuthally averaged stellar age and metallicity profiles for ∼ 500 galaxies, using both luminosity-weighted Lick indices and mass-weighted full spectral fitting. We find a weak trend for steeper (i.e. more negative) metallicity gradients in more massive galaxies, however, below stellar masses ∼ 1010.5 M⊙, the scatter in metallicity gradient increases dramatically.

This contribution briefly summarizes the current state of our knowledge about the Milky Way's nuclear star cluster.

Protoclusters at high redshifts are the ideal laboratories to study how the environmental dependences of galaxy properties seen in local Universe were initially set up when the progenitors of present-day early-type galaxies were in their early formation phases. We have conducted a deep near-infrared spectroscopy of Hα emitters (HAEs) associated with two protoclusters (PKS 1138–262 at z = 2.16 and USS 1558–003 at z = 2.53) with the Multi-Object Infrared Camera and Spectrograph (MOIRCS) on the Subaru telescope.

As a result, the cluster membership of 27 and 36 HAEs are newly confirmed in these two protoclusters, respectively. The inferred dynamical masses of the protocluster cores are consistent with being the typical progenitors of present-day most massive clusters (Shimakawa et al.2014a). Also, those HAEs in the protoclusters show much higher [OIII]/Hβ ratios than local star forming galaxies. It is probably caused by the combination of their much higher specific star formation rates, lower gaseous metallicities and redshift evolution of inter-stellar medium. We also find that the mass-metallicity relation in the protocluster galaxies is offset to higher metallicity compared to those of field galaxies at a given stellar mass at M∗<1011M⊙ (Shimakawa et al.2014b). This trend is compatible with the recent work (Kulas et al.2013). The mass-metallicity relation is regulated not only by star formation history hence metal production history, but also by inflow and outflow processes that are known to be very active at z > 2 (Steide et al.2010). It suggests that the higher gaseous metallicities of protocluster galaxies may be caused by those gas transfer processes that are dependent on surrounding environments.

I briefly explore some relevant connections and differences between the evolutionary paths of dwarf galaxies and globular clusters.

Various previous galaxy surveys have revealed that different types of galaxies show different spatial distributions. By comparing their clustering strengths, we can investigate the relationship between the environments where galaxies reside and the properties of galaxies. This provides us vital information on when, where, and how galaxies are formed. In this study, we focus on FIR-selected galaxies from AKARI All-Sky Survey, which are considered to be dusty star-forming galaxies. We measure their power spectrum and compare our final result with previous studies using different galaxy samples detected at other wavelengths. It is found that there is the very clear wavelength dependence of the clustering strength.

We present the star formation histories (SFHs) of four isolated dwarf galaxies, Cetus, Tucana, LGS-3, and Phoenix, as a function of galactocentric radius. Our results suggest that beyond some distance from the center, there are no significative differences in fundamental properties of these galaxies, such as the star formation rate (SFR) or age-metallicity relation (AMR). The stellar content of this region would be composed of old (≳ 10.5 Gyr) metal-poor stars only. In the innermost regions, dwarf galaxies appear to have formed stars during time intervals which duration varies from galaxy to galaxy. This extended star formation produces the dichotomy between dwarf spheroidal (dSph) and dwarf Transition (dTr) galaxy types.

It seems that in the past decade, there have been two paradigm shifts regarding star clusters. Firstly, the observational evidence for multiple stellar populations requires more extended and often complex star formation histories in star clusters. Secondly, theoretical models that form globular clusters in dwarf galaxies that are accreted at very early epochs (z > 5) are able to reproduce the age-metallicity relations observed. For the accretion scenario to be viable, globular clusters should also resemble the chemistry of at least some dwarf galaxies.

Dynamical mass estimates (${\cal M}_{\rm dyn}$) and mass-to-light ratios ($\Upsilon_{\rm dyn}$) were derived for a sample of NGC 5128's globular clusters (GCs). We find two distinct sequences in the $\Upsilon_{\rm dyn}$ − ${\cal M}_{\rm dyn}$ plane, which are well fit by power laws of the forms $\Upsilon_{\rm dyn}\propto {\cal M}_{\rm dyn}^{0.33\pm0.04}$ and $\Upsilon_{\rm dyn}\propto {\cal M}_{\rm dyn}^{0.91\pm0.04}$. The former traces bright “classical” GCs, and the latter represents objects that are dynamically dominated by large dark matter components or by abnormally massive central black holes.

The primary data product of a recent Keck/DEIMOS spectroscopic campaign of eight Milky Way dwarf spheroidal (dSph) satellite galaxies is a catalog of nearly 3000 red giants with spectral synthesis-based abundance measurements of Fe and the α elements Mg, Si, Ca, and Ti. The dSph metallicity distributions show that the histories of the less luminous dSphs were marked by massive amounts of metal loss. The [α/Fe] distributions reveal that the early star formation histories (at a lookback time of >12 Gyr) of most dSphs were very similar and that Type Ia supernova ejecta contributed to the abundances of all but the most metal-poor ([Fe/H] < −2.5) stars. This large data set allows inferences of past outflows from the dSphs in order to determine their contribution to the metal content of the intergalactic medium.

In the context of the formation of spiral galaxies the evolution and distribution of the angular momentum of dark matter halos have been discussed for more than 20 years, especially the idea that the specific angular momentum of the halo can be estimated from the specific angular momentum of its disk (e.g. Fall & Efstathiou (1980), Fall (1983) and Mo et al. (1998)). We use a new set of hydrodynamic cosmological simulations called Magneticum Pathfinder which allow us to split the galaxies into spheroidal and disk galaxies via the circularity parameter ϵ, as commonly used (e.g. Scannapieco et al. (2008)). Here, we focus on the dimensionless spin parameter λ = J |E|1/2 / (G M5/2) (Peebles 1969, 1971), which is a measure of the rotation of the total halo and can be fitted by a lognormal distribution, e.g. Mo et al. (1998). The spin parameter allows one to compare the relative angular momentum of halos across different masses and different times. Fig. 1 reveals a dichotomy in the distribution of λ at all redshifts when the galaxies are split into spheroids (dashed) and disk galaxies (dash-dotted). The disk galaxies preferentially live in halos with slightly larger spin parameter compared to spheroidal galaxies. Thus, we see that the λ of the whole halo reflects the morphology of its central galaxy. For more details and a larger study of the angular momentum properties of disk and spheroidal galaxies, see Teklu et al. (in prep.).