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Active Galactic Nuclei (AGN) are objects in which a supermassive black hole is fed by gas and, as this generates energy, can ionise the environment and interact with it by jets and winds. This work is focused on the processes of feeding and feedback in the nucleus of NGC 613. This object is a case in which both phenomena can be studied in some detail. The kinematics and morphology of the molecular gas trace the feeding process while the ionization cone, seen in [O iii]λ5007 and soft X-rays, as well as the radio jet and wind/outflows are associated with feedback processes. In addition, we see 10 HII regions, associated with nuclear and circumnuclear young stellar populations, dominant in the optical, that makes the analysis complicated, though more interesting. For all these phenomena, NGC 613 nucleus is a vibrant example of the interplay between the AGN and the host galaxy.

We use near-infrared Integral Field Unit (IFU) data to analyze the galaxies NGC 4151 and NGC 1068, which have very different Eddington ratios - ˜50 times lower for NGC 4151. Together with a detailed data cube treatment methodology, we reveal remarkable similarities between both AGN, such as the detection of the walls of an “hourglass” structure for the low-velocity [Fe ii] emission with the high-velocity emission within this hourglass; a molecular outflow - detected for the first time in NGC 4151; and the fragmentation of an expanding molecular bubble into bullets of ionized gas. Such observations suggest that NGC 4151 could represent a less powerful and more compact version of the outflow seen in NGC 1068, suggesting a universal feedback mechanism acting in quite different AGN.

We identify a class of four Galactic stars with similar spectroscopic and photometric properties: V617 Sgr, HD 104994, WX Cen, and V Sge. We call this class the “V Sagittae stars.” The characteristics and literature of each of these stars are reviewed. They show high‐ionization species like Oviand Nv; the emission of Heiiλ4686 is stronger than twice the strength of Hβ. The orbital periods vary from 5 to 12 hr, and the orbital light curve can have shapes of either double eclipse or sine wave. The close similarities of these objects to the supersoft X‐ray sources is pointed out. The nature of the compact star in these system is still an open question; white dwarfs, neutron stars, black holes, or carbon main‐sequence stars have been proposed.

In this work, we present preliminary results regarding the nuclear emission lines of a statistically complete sample of 56 early-type galaxies that are part of the Deep Integral Field Spectroscopy View of Nuclei of Galaxies (DIVING3D) Project. All early type galaxies (ETGs) were observed with the Gemini Multi-Object Spectrograph Integral Field Unit (GMOS-IFU) installed on the Gemini South Telescope. We detected emission lines in 93% of the sample, mostly low-ionization nuclear emission-line region galaxies (LINERs). We did not find Transition Objects nor H II regions in the sample. Type 1 objects are seen in ∼23% of the galaxies.

The DIVING3D Survey (Deep Integral Field Spectrograph View of Nuclei of Galaxies) aims to observe, with high signal/noise and high spatial resolution, a statistically complete sample of southern galaxies brighter than B = 12.0 The main objectives of this survey are to study: 1) the nuclear emission line properties; 2) the circumnuclear emission line properties; 3) the central stellar kinematics and 4) the central stellar archaeology. Preliminary results of individual or small groups of galaxies have been published in 18 papers.

In this work we derive stellar archaeology and kinematics of the central 400 pc of NGC 5643. The star formation history (SFH) reveals nuclear contribution of stellar populations older (20% older than 3.5 Gyr) and younger (60% younger than 320 Myr) as compared to the circumnuclear region. The [OIII] 5007 Å kinematics reveals the eastern ionization cone with an outflow (−60 km/s ⩽ v ⩽ 120 km/s).

The aim of diagnostic diagrams is to classify galactic nuclei according to their photoionizing source using emission-line ratios, differentiating starburst regions from active galactic nuclei (AGN). However, the three traditional diagnostic diagrams can sometimes be ambiguous with regard to a single object. The main goal of the present work is to propose alternative diagnostic diagrams by using distinct combinations of emission lines ratios. We present these diagrams using data from the Sloan Digital Sky Survey. With these new diagrams, it is possible to better distinguish the ionizing source in nuclei of galaxies and also to study the parameters that are relevant when considering both kinds of objects, starbursts and AGN.

We present the first results of the Deep Integral Field Spectroscopy View of Nuclei of Galaxies (DIVING3D) survey, obtained from the analysis of the nuclear emission-line spectra of a sub-sample we call mini-DIVING3D, including all southern galaxies with B < 11.2 and |b| >15°. In comparison with previous studies, very few galaxies were classified as Transition objects. A possible explanation is that at least part of the Transition objects are composite systems, with a central low-ionization nuclear emission-line region (LINER) contaminated by the emission from circumnuclear H II regions. The high spatial resolution of the DIVING3D survey allowed us to isolate the nuclear emission from circumnuclear contaminations, reducing the number of Transition objects.

Context: we present a study of the central 200 pc of NGC 6951, in the optical and NIR, taken with the Gemini North Telescope integral field spectrographs, with resolution of ~ 0”.1 Methods: we used a set of image processing techniques, as the filtering of high spatial and spectral frequencies, Richardson-Lucy deconvolution and PCA Tomography (Steiner et al.2009) to map the distribution and kinematics of the emission lines. Results: we found a thick molecular disk, with the ionization cone highly misaligned.