Related papers: When SN explode in a Starburst: Transitions among …
Some catastrophic stellar explosions, such as supernovae (SNe), compact binary coalescences, and micro-tidal disruption events, are believed to be embedded in the accretion disks of active galactic nuclei (AGN). We show high-energy…
I review the relationship between star formation and black hole building, based on spectroscopic observations of the stellar population in active galactic nuclei (AGNs) and their host galaxies. My emphasis is on large, well-defined local…
NGC 4945 is a nearby (3.8 Mpc) galaxy hosting a nuclear starburst and Seyfert Type 2 AGN. We use the Atacama Large Millimeter/submillimeter Array (ALMA) to image the 93 GHz (3.2 mm) free-free continuum and hydrogen recombination line…
One of the most intriguing open issues in galaxy evolution is the structure and evolution of active galactic nuclei (AGN) that emit intense light believed to come from an accretion disk near a super-massive black hole (Rees 1984,…
We present an analysis of historical multi-wavelength emission of the Changing Look (CL) Active Galactic Nucleus (AGN) in NGC 2992, covering epochs ranging from 1978 to 2021, as well as new X-ray and optical spectra. The galaxy presents…
Active Galactic Nuclei (AGN) are energetic astrophysical sources powered by accretion onto supermassive black holes in galaxies, and present unique observational signatures that cover the full electromagnetic spectrum over more than twenty…
We present HST (WFPC2 and FOC) images and UV GHRS spectra plus ground-based optical spectra of four Luminous Infrared Galaxies (LIRGs) that have Seyfert 2 nuclei (Mrk 477, NGC 7130, NGC 5135 and IC 3639). The data provide direct evidence of…
Circumnuclear star formation (SF) is generally seen in galaxies hosting active galactic nuclei (AGN); however, the connection between the AGN activity and SF in them is less well understood. To explore this connection on scales of a few…
We report R~3000 VLT ISAAC K-band spectroscopy of the nuclei (i.e. central 100-300pc) of 9 galaxies hosting an active galactic nucleus. For 5 of these we also present spectra of the circumnuclear region out to 1kpc. We have measured a…
Active Galactic Nuclei (AGN) are ideal sources for multi-wavelength studies as their emission can cover almost 20 orders of magnitude in frequency from the radio to the gamma-ray band. After reviewing their basic properties, I will assess…
The strongest starbursts are observed towards galaxy nuclei, or circumnuclear regions. However in interacting galaxies, star formation is also triggered in overlap regions far from nuclei, in spiral arms and sometimes in tidal tails. What…
We study galaxies that host both nuclear star clusters and active galactic nuclei (AGN) implying the presence of a massive black hole. We select a sample of 176 galaxies with previously detected nuclear star clusters that range from…
The role of stars and starbursts in AGN has been a recurring issue for nearly as long as AGN have been recognized as hosts of interesting phenomena. The heated ``starburst X monster'' controversy of the 80's and 90's was gradually replaced…
Observations at multiple wavelengths are reviewed to search for evidence for fueling mechanisms in galaxies, both for nuclear starbursts and AGN activity. Although it is undisputed that dynamical perturbations such as bars or tidal…
There are several key open questions as to the nature and origin of AGN including: 1) what initiates the active phase, 2) the duration of the active phase, and 3) the effect of the AGN on the host galaxy. Critical new insights to these can…
Active Galactic Nuclei are fueled from material (gas or stars) that are in general far away from the gravitational influence of the central black hole, the engine thought to be responsible for their activity. The required material has a lot…
As active galactic nuclei (AGN) `turn on', some stars end up embedded in accretion disks around supermassive black holes (SMBHs) on retrograde orbits. Such stars experience strong headwinds, aerodynamic drag, ablation and orbital evolution…
Thanks to the advent of large-scale optical surveys, a diverse set of flares from the nuclear regions of galaxies has recently been discovered. These include the disruption of stars by supermassive black holes at the centers of galaxies -…
The relationship between an active galactic nucleus (AGN) and its host galaxy is still far from being understood. Properties of the host galaxies of Seyfert nuclei, such as luminosity concentration, morphological type, metallicity, and age…
By considering the radiative force by a circumnuclear starburst as well as an AGN, we analyze the equilibrium configuration and the stability of dusty gas in the circumnuclear regions. It is found that the radiative force by an intensive…