Related papers: Nuclear Activity in UZC Compact Groups of Galaxies
(Abridged) We present a detailed study of the relation between circumnuclear dust morphology, host galaxy properties, and nuclear activity in nearby galaxies. We use our sample of 123 nearby galaxies with visible--near-infrared colormaps…
We have studied the X-ray nuclear activity of 187 nearby (distance < 15 Mpc) galaxies observed with Chandra/ACIS. We found that 86 of them have a point-like X-ray core, consistent with an accreting black hole (BH). We argue that the…
In a series of papers based on the FIRST and Sloan Digital Sky Surveys (SDSS), we investigate the local population of star-forming galaxies and Active Galactic Nuclei (AGN) in order to clarify the link between these two types of activity,…
In this paper, we report a detailed study with a variety of data from optical, near-infrared, X-ray, and radio telescopes of the nuclear region of the galaxy NGC 613 with the aim of understanding its complexity. We detected an extended…
We present analysis of 63 nearby ($<$ 44 Mpc) early-type galaxies hosting nuclear star clusters using the recently discovered parameter Central Intensity Ratio (CIR$_I$) determined from near-infra-red (3.6 $\mu$m) observations with the…
We present an analysis of a large sample of AGN environments at z~1 using stacked Spitzer data at 3.6um. The sample contains type-1 and type-2 AGN in the form of quasars and radio galaxies, and spans a large range in both optical and radio…
We visually and quantitatively determine the host galaxy morphologies of 94 intermediate redshift (0.2 < z < 1.2) active galactic nuclei (AGN), selected using Chandra X-ray and Spitzer mid-infrared data in the Extended Groth Strip. Using…
Several studies of nearby active galaxies indicate significantly higher HCN-to-CO intensity ratios in AGN than in starburst (SB) environments. HCN enhancement can be caused by many different effects, such as higher gas…
Active galactic nuclei (AGN) are believed to be promising candidates of extragalactic cosmic-ray accelerators and sources, and associated high-energy neutrino and hadronic gamma-ray emission has been studied for many years. We review models…
We study the connection between active galactic nuclei (AGN) and their host galaxies through cosmic time in the large-scale cosmological IllustrisTNG simulations. We first compare BH properties, i.e. the hard X-ray BH luminosity function,…
We study the relation of active galactic nuclei (AGNs) to star formation in their host galaxies. Our sample includes 205 Type-1 and 85 Type-2 AGNs, 162 detected with Herschel, from fields surrounding 30 galaxy clusters in the Local Cluster…
The most rapidly evolving regions of galaxies often display complex optical spectra with emission lines excited by massive stars, shocks and accretion onto supermassive black holes. Standard calibrations (such as for the star formation…
Physical processes such as re-ignition, enhancement, and fading of active galactic nuclei (AGN) are not entirely understood because the timeline of these events is expected to last many years. However, it is well known that the differences…
The sources of the majority of the high-energy astrophysical neutrinos observed with the IceCube neutrino telescope at the South Pole are unknown. So far, only a gamma-ray blazar was compellingly associated with the emission of high-energy…
We obtained long-slit optical spectra of the nuclear regions of 376 galaxies in the local Universe using the 1.5m Cassini telescope of Bologna Observatory. Of these spectra, 164 were either never taken before by the Sloan Digital Sky Survey…
The existence of correlations between nuclear properties of galaxies, such as the mass of their central black holes, and larger scale features, like the bulge mass and luminosity, represent a fundamental constraint on galaxy evolution.…
A consensus is emerging that interacting galaxies show depressed nuclear gas metallicities compared to isolated star-forming galaxies. Simulations suggest that this nuclear underabundance is caused by interaction-induced inflow of…
Using a sample of 91 galaxies distributed over 27 Compact Groups of Galaxies (CGs), we define an index that allows us to quantify their level of activity, be it AGN or star formation. By combining the mean activity index with the mean…
Aims. We present results of a comprehensive spectral study on the large-scale environment of AGNs based on Sloan Spectroscopic Survey data. Methods. We analyzed the spectra of galaxies in the environment of AGN and other activity classes up…
Nuclear activity in galaxies is closely connected to galactic mergers and supermassive black holes (SBH). Galactic mergers perturb substantially the dynamics of gas and stellar population in the merging galaxies, and they are expected to…