Two classes of spectro-imagers are available, the first one, usually based on grisms, allows to cover intermediate fields of view and wide spectral ranges (decreasing when the spectral resolution increases) while the second one, usually based on tunable filters (like Fabry-Perot), is generally able to cover larger fields of view but on narrow spectral ranges (also depending on the spectral resolution). Both families of instrument have access to low or high spectral resolution and are used in seeing limited conditions for observing nearby galaxies. Spectro-imagers provide data cubes consisting of a spectrum for each spatial sample on the sky. From these spectra, using both emission and absorption lines, combined with the continuum emission, the history of the stars and the interstellar medium in nearby galaxies, encoded in different physical quantities, such as chemical abundances, kinematics properties, is deciphered. Only a few surveys of galaxies using spectro-imagers have been led up to now and mainly using 4-m class or smaller telescopes. This includes the case of nearby late-type galaxies surveyed in the optical. Two large surveys of some 600 galaxies each have just been launched, one on the Magellan 6m telescope (CGS) and the other one on the William Herschel 4.2m telescope (CALIFA). Surveys containing a smaller number of galaxies have been conducted elsewhere, for instance on the WIYN and Calar Alto 3.5m telescopes (the DiskMass survey, 146 galaxies); on the ESO and CFHT 3.6m telescopes (CIGALE, 269 galaxies); on the OHP 1.92m telescope (GHASP, 203 galaxies); on the mont Mégantic 1.6m telescope (107 galaxies) and on the San Pedro Mártir 2.1m telescope (79 galaxies). Other programs surveying less then 50 galaxies have been also led, like VENGA, SAURON, PINGS or GHaFaS. The scientific drivers of these surveys are broad, they span from the study of the structural properties, star formation histories, AGN content, to mass profiles and uncertainties in rotation-curve decompositions, nature and formation of bulges and disks components.

This contribution gives a short overview of the MeerKAT Karoo Array Telescope, the South African Square Kilometre Array Precursor. Some of the key specification and HI emission line science for MeerKAT are described.

Integral-Field Units have been used to describe the morphology in numerous continuum and line wavebands of a sample of barred spirals galaxies (some of which known as starbursts and LINERs) and to characterize their gas and stellar populations. The central region of eight galaxies was studied with OASIS and an iterative technique developed to separate superposed stellar populations. Young populations, responsible for nebular emission lines, are found in nuclear structures. Older stellar components are mostly uniformly distributed. The mass distribution of the different populations indicates a long sequence of burst events over the whole galaxy history. An activity of the type composite/transition region is often seen over the whole central region. SpIOMM was also used to map the emission lines over the entire disk of one of these galaxies. Among other results, it confirms the peculiar line ratio.

SpIOMM, a wide-field Imaging Fourier Transform Spectrometer attached to the Mont Mégantic 1.6-m telescope, is capable of obtaining the visible spectrum of every source of light in a 12 arcminute field of view, with a spectral resolution ranging from R = 1 (wide-band image) to R = 25 000, resulting in 1.7 million spectra with a spatial resolution of one arcsecond. SITELLE will be a similar instrument attached to the Canada-France-Hawaii telescope, and will be in operation in early 2013. We present a short description of these instruments and illustrate their capabilities to study nearby galaxies with the results of a data cube of M51.

A 10-metre class telescope project on African soil is ending its commissioning period and is transitioning to science mode. We present the current status of the Southern African Large Telescope and its instruments. We will also briefly discuss the SALT capabilities for extragalactic astronomy in particular.

With SpIOMM, we obtained numerous spectra in the visible range covering simultaneously several emission lines of bright Hii regions in the spiral galaxies NGC 628 and M101. We measured the size and luminosity of the Hii regions as well as the gas metallicity, temperature, and density. We estimated the age and star forming rate of the young stellar populations associated with the Hii regions. We looked for gradients along the galaxy radius and search for relations with the galactic arm positions. This is a first step in a project, based on a detailed study of stellar populations, to rebuild the history of spiral galaxies and to identify the mechanisms responsible for their evolution.

We performed a deep Hi and Hα mapping of M31 and M33 in order to get accurate kinematical data of those two galaxies and also to make a comparison between the Hi and Hα kinematics. The Hi data were obtained with the DRAO interferometer and the Hα data with the Fabry-Perot system of the Observatoire du mont Mégantic using an EMCCD as a detector. These data will give us the best possible datasets to derive accurate rotation curves and mass models for those two Local Group spirals and provide some new data for the Hii regions studies of these galaxies. While the Hi observations are of low resolution (~1 arcmin), the high resolution of the Hα data (~1 arcsec) should allow us to get much more details in the central regions, allowing at the same time a much better determination of the kinematical parameters. Hence, the inner part of the rotation curve, so inportant to constraint properly the mass models, will be determined more accurately.

Deep spectroscopic redshift surveys have become an important tool for observational cosmology, supported by a new generation of wide field multi-object spectrographs. They bring high redshift accuracy and a wealth of spectral features necessary for precision astrophysics and have led to the outstanding progress in our understanding of the different phases of galaxy evolution. The measurement of the evolution of volume quantities like the luminosity and mass functions or the correlation function, has enabled a deep insight into galaxy evolution since redshifts z ≃ 7. The redshift distribution N(z,m) is a basic property but is still difficult to be reproduced by models. We have now a global perspective on the history of star formation with a peak at z = 1−2 but the decline in SFRD at higher redshifts is still to be confirmed. The evolution of the stellar mass density with a fast growth in red passive galaxies between z = 2 and z = 1 is well established. The contribution to galaxy mass assembly of key physical processes like merging or cold accretion is now well documented. However, the pioneer measurements at the high redshift end z > > 1 remain to be consolidated with robust sample selection and statistical accuracy from large spectroscopic redshift surveys, a challenge for the years to come.

I review the major surveys of high redshift galaxies observed using integral field spectroscopy techniques in the visible and in the infrared. The comparison of various samples has to be done with care since they have different properties linked to their parent samples, their selection criteria and the methods used to study them. I present the various kinematic types of galaxies that are identified within these samples (rotators, mergers, etc.) and summarize the discussions on the mass assembly processes at various redshifts deduced from these classifications: at intermediate redshift (z ~ 0.6) merger may be the main mass assembly process whereas the role of cold gas accretion along cosmic web filaments may increase with redshift. The baryonic Tully-Fisher relation is also discussed. This relation seems to be already in place 3 Gyr after the Big-Bang and is then evolving until the present day. This evolution is interpreted as an increase of the stellar mass content of dark matter haloes of a given mass. The discovery of positive abundance gradients in MASSIV and LSD/AMAZE samples is highlighted. At z ~ 3 this discovery might be linked to cold gas accretion along cosmic filaments toward the centre whereas at lower redshift (z ~ 1.3), this may be mainly due to accretion of gas from outer reservoirs toward the centre via tidal tails due to interactions.

Understanding the different mechanisms of galaxy assembly at various cosmic epochs is a key issue for galaxy evolution and formation models. We present MASSIV (Mass Assembly Survey with SINFONI in VVDS) in this context, an on-going survey with VLT/SINFONI aiming to probe the kinematics and chemical abundances of a unique sample of 84 star-forming galaxies selected in the redshift range z ~ 1−2. This large sample, spanning a wide range of stellar masses, is unique at these high redshifts and statistically representative of the overall galaxy population. In this paper, we give an overview of the MASSIV survey and then focus on the spatially-resolved chemical properties of high-z galaxies and their implication on the process of galaxy assembly.

Scaling relations are salient ingredients of galaxy evolution and formation models. I summarize results from the IMAGES survey, which combines spatially-resolved kinematics from FLAMES/GIRAFFE with imaging from HST/ACS and other facilities. Specifically, I will focus on the evolution of the stellar mass and baryonic Tully-Fisher Relations (TFR) from z = 0.6 down to z = 0. We found a significant evolution in zero point and scatter of the stellar mass TFR compared to the local Universe. Combined with gas fractions derived by inverting the Schmidt-Kennicutt relation, we derived for the first time a baryonic TFR at high redshift. Conversely to the stellar mass TFR, the baryonic relation does not appear to evolve in zero point, which suggests that most of the reservoir of gas converted into stars over the past 6 Gyr was already gravitationally bound to galaxies at z = 0.6.

Selection effects in the submillimeter/far-infrared inhibit detailed analysis of extreme starbursts in the early Universe. Submillimeter Galaxy (SMG) detection and characterization biases against warm temperature SEDs Tdust ~50 K, against the highest redshift ULIRGs z > 3, and has so far been limited to a small sample of ~100 sources that have reliably identified optical or radio counterparts and spectroscopic redshifts. Recent observations by Herschel ⋅ ⋅ ⋅ ⋅ and ⋅ ⋅ ⋅⋅ ⋅ in the ~70–500 μm wavelength range provide a more complete census of high-z ULIRG activity than previous SMG surveys. However, source confusion and lack of spectroscopic identification of reliable counterparts limit the analysis of extreme ULIRGs to the most basic calculations, frought with a priori assumptions (e.g. Tdust/(1+z) degeneracy, far-IR/radio relation, confusion boosting factors, etc). Herein I address the biases on conclusions of SMG work and I demonstrate the need for thorough, spectroscopic follow-up of high-z ULIRGs in order to infer their physical conditions.

Lyman Break Analogs (LBAs), characterized by high far-UV luminosities and surface brightnesses as detected by GALEX, are intensely star-forming galaxies in the low-redshift universe (z ~ 0.2), with star formation rates reaching up to 50 times that of the Milky Way. These objects present metallicities, morphologies and other physical properties similar to higher redshift Lyman Break Galaxies (LBGs), motivating the detailed study of LBAs as local laboratories of this high-redshift galaxy population. We present results from our recent integral-field spectroscopy survey of LBAs with Keck/OSIRIS, which shows that these galaxies have the same nebular gas kinematic properties as high-redshift LBGs. We argue that such kinematic studies are not an appropriate diagnostic to rule out merger events as the trigger for the observed starburst. Comparison between the kinematic analysis and morphological indices from HST imaging illustrates the difficulties of properly identifying (minor or major) merger events, with no clear correlation between the results using either of the two methods. Artificial redshifting of our data indicates that this problem becomes even worse at high redshift due to surface brightness dimming and resolution loss. Whether mergers could generate the observed kinematic properties is strongly dependent on gas fractions in these galaxies. We present preliminary results of a CARMA survey for LBAs and discuss the implications of the inferred molecular gas masses for formation models.

The utilization of integral-field spectroscopy has led us to a new understanding of the physical conditions in galaxies within the first few billion years after the Big Bang. In this proceedings, we analyze observations of ~50 massive galaxies as seen as they were 10 Gyrs ago using SINFONI from the ESO-VLT. We show that the large line width they exhibit can be explained by the intense mechanical energy output from the young stars. We also study the influence of cold gas accretion upon these galaxies: We show that an unrealistic amount of shocked gas would be needed in order to explain the Hα emission from these galaxies through shocks from gas accretion with velocity about the Hα line widths of these galaxies. We also use DEEP2 photometric measurements for a sub-sample of 10 of these galaxies to evaluate their ratio of Hα to FUV flux as a function of their Hα and R-band luminosity surface brightnesses. Our data suggests that perhaps their initial mass function (IMF) is flatter than Salpeter at the high mass end, as has been suggested recently for some local galaxies. It may be that high turbulence is responsible for skewing the IMF towards more massive stars as suggested by some theories of star-formation. Much work is however needed to accredit this hypothesis.

The three-dimensional visualization of redshift surveys is a key player in the comprehension of the structuration of the cosmic web. The SDvision software package, intended primarily for the visualization of massive cosmological simulations, has been extended to provide an interactive visual representation of different classes of redshift surveys, with the objective to enable direct comparisons between the rare highest-density peaks traced by the clusters of galaxies found in the XMM-LSS Survey and the densely populated catalogues of galaxy photometric redshifts. We present the various possibilities offered by this tool in terms of filtering of the data, reconstruction of density fields, interactivity and visual rendering, including various techniques such as ray-casting, isosurfaces, slicing and texturing. This is illustrated using the C1 and C2 samples of the XMM-LSS Survey, and the publicly released COSMOS and CFHTLS photometric redshift Catalogs. Comparisons with published results are presented and discussed.

Stellar populations carry information about the formation of galaxies and their evolution up to the present epoch. A wealth of observational data are available nowadays, which are analysed with stellar population models in order to obtain key properties such as ages, star formation histories, stellar masses. Differences in the models and/or in the assumptions regarding the star formation history affect the derived properties as much as differences in the data. I shall review the interpretation of high-redshift galaxy data from a model perspective. While data quality dominates galaxy analysis at the highest possible redshifts (z > 5), population modelling effects play the major part at lower redshifts. In particular, I discuss the cases of both star-forming galaxies at the peak of the cosmic star formation history as well as passive galaxies at redshift below 1 that are often used as cosmological probes. Remarks on the bridge between low and high-z massive galaxies conclude the contribution.

We have carried out a detailed analysis of stellar properties of bars and bulges of a sample of early-type galaxies. We have also compared the results of the bulge properties with the bulges of a similar sample of unbarred galaxies, deriving the SSP equivalent stellar parameters in the same way as for our sample. We are currently characterising the nebular gas in the bulges of the sample galaxies. We have found differences in the bulge stellar population properties between barred and unbarred galaxies. The bulges of barred galaxies seem to be more metal rich, at a given velocity dispersion (σ), than the bulges of unbarred galaxies, as measured by some metallicity sensitive indices. There are indications that the ratio of relative abundance of alpha-elements with respect to iron, [E/Fe], derived for the bulges of barred galaxies tend to lie above the values of the unbarred galaxies at a given σ. We also find three different types of bars according to their metallicity and age distribution along the radius: 1) Bars with negative metallicity gradients. They show mean young/intermediate population (<2 Gyr), and have amongst the lowest stellar maximum central velocity dispersion of the sample. 2) Bars with null metallicity gradients. These galaxies that do not show any gradient in their metallicity distribution along the bar and have negative age gradients (i.e younger populations at the bar end). 3) Bars with positive metallicity gradients, i.e. more metal rich at the bar ends. These galaxies are predominantly those with higher velocity dispersion and older mean population. We find no significant correlation between the age and metallicity distribution, and bar/galaxy parameters such as the AGN presence, size or the bar strength. From the kinematics, we find that all the galaxies show a disk–like central component. Regarding the ionised gas properties, we find that the nebular metallicity gradients are shallower than the stellar ones, indicating an efficient mixing of the material currently forming. The nebular central metallicities do not show a correlation with the central σ, and, furthermore, in some cases the nebular metallicities are clearly lower than the stellar ones, indicating an external origin for the gas fueling the current star formation. All these results point to a scenario, at least for early-type galaxies, where bars are long-lived and where the formation of the bulge and the bar are closely linked. Later accretion of gas can then be funneled towards the center forming nuclear discs and rings, producing substructures with low level of star formation, but that would not contain enough stars to produce a change in the SSP-equivalent metallicities and [E/Fe].

We have found that local galaxies follow a very tight relation between gas metallicity, stellar mass and SFR, suggesting that their evolution is characterized by a long standing equilibrium between gas inflows, outflows and star formation. Surprisingly, even distant galaxies, out to z < 2.5, follow the same relation, suggesting that the same dominant mechanism of galaxy evolution is in place at any epoch, out to z < 2.5. However, by using deep near-IR spectroscopy (probing optical nebular lines at high-z), we find that galaxies at z > 3 deviate from such fundamental relation, by being significantly more metal poor. Spatially resolved metallicity maps of z > 3 disk galaxies reveal that they are characterized by central regions with low metallicity associated with the peak of star formation, indicating that the latter is due to massive inflow of pristine gas that both boosts star formation and dilutes the gas metallicity. Overall these results suggest that the metallicity evolution of galaxies at z > 3 is due to an excess of gas inflow at such early epochs, as expected by some recent models. Finally, we investigate the metallicity of merging systems, both locally and at high-z. By exploiting recent Herschel data, we have found that in these systems the dust content directly measured through the FIR-submm data is much higher than inferred from the metallicity measured through the optical nebular lines. The latter result suggests that, in these heavily obscured systems, optical observations only probe the outer, less enriched regions and are not representative of the bulk of the metal content.

We derive the full chemical enrichment histories for 3800 early-type galaxies, including both star forming and passively evolving systems. For this purpose we have developed a method to simultaneously derive the element abundance ratios [C/Fe], [N/Fe], [Mg/Fe], [Ca/Fe] and [Ti/Fe] for unresolved stellar populations. The method is based on up-to-date stellar population models with varying element abundance ratios. A novelty of the models is that they are flux-calibrated, removing the dependence on the Lick/IDS system. Trends with velocity dispersion are investigated where [Mg/Fe] and [C/Fe] are found to show very similar trends, while [N/Fe] show overall lower abundances ratios. [Ca/Fe] ratios are close to solar values over the velocity dispersion range covered. Tentative, due to large scatter, result for [Ti/Fe] implies that Ti follow the trends of Ca.

Galaxy-galaxy interactions and large scale galaxy bars are usually considered as the two main mechanisms for driving gas to the centres of galaxies. By using large samples of galaxy pairs and visually classified bars from the Sloan Digital Sky Survey (SDSS), we compare the relative efficiency of gas inflows from these two processes. We use two indicators of gas inflow: star formation rate (SFR) and gas phase metallicity, which are both measured relative to control samples. Whereas the metallicity of galaxy pairs is suppressed relative to its control sample of isolated galaxies, galaxies with bars are metal-rich for their stellar mass by 0.06 dex over all stellar masses. The SFRs of both the close galaxy pairs and the barred galaxies are enhanced by ~60%, but in the bars the enhancement is only seen at stellar masses M∗ > 1010 M⊙. Taking into account the relative frequency of bars and pairs, we estimate that at least three times more central star formation is triggered by bars than by interactions.