Related papers: The Narrow Line Region: Current Models and Future …
We present results from a study of high- and low-ionization emission line ratios as a function of projected velocity for a sample of eight active galactic nuclei (AGNs). Our results are based on analysis of high signal-to-noise optical and…
The last decade saw long-awaited improvements in our understanding of active galactic nuclei (AGN) spectral properties. This contribution reviews some important observational results obtained from optical and UV data as well as constraints…
Line profiles can provide fundamental information on the physics of active galactic nuclei (AGN). In the case of narrow-line Seyfert 1 galaxies (NLS1s) this is of particular importance since past studies revealed how their permitted line…
We present a new model to explain the appearance of red/blue-shifted broad low-ionization emission lines, especially emission lines in optical band, which is commonly considered as an indicator of radial motion of the line emitting gas in…
We present an adapted version of the code HII-CHI-Mistry-UV (P\'erez-Montero & Amor\'in 2017) to derive chemical abundances from emission lines in the ultraviolet, for use in narrow line regions (NLR) of Active Galactic Nuclei (AGN). We…
We present the implementation of dusty, radiation pressure dominated photoionization models applicable to the Narrow Line Regions (NLRs) of Active Galactic Nuclei, using the \mapiii code. We give a grid of the predicted intensities of the…
Models of radiation transport in stellar atmospheres are the hinge of modern astrophysics. Our knowledge of stars, stellar populations, and galaxies is only as good as the theoretical models, which are used for the interpretation of their…
Emission lines in X-ray spectra of clusters of galaxies reveal the presence of heavy elements in the diffuse hot plasma (the Intra Cluster Medium, or ICM) in virial equilibrium in the dark matter potential well. The relatively simple…
Recently growing evidence has been accumulated that the NLS1s are viewed from nearly pole-on viewing angles. However, there has been no theoretical model which explains the following important correlations; 1) weaker optical Fe II emitters…
This work presents the first results of the Deep IFS View of Nuclei of Galaxies (DIVING$^\mathrm{3D}$) survey. We analysed the nuclear emission-line spectra of a sub-sample we call mini-DIVING$^\mathrm{3D}$, which includes all Southern…
X-ray observations of several active galactic nuclei show prominent iron K-shell fluorescence lines that are sculpted due to special and general relativistic effects. These observations are important because they probe the space-time…
Understanding the ionizing spectrum of low-metallicity galaxies is of great importance for modeling and interpreting emission line observations of early/distant galaxies. Although a wide suite of stellar evolution, atmosphere, population…
We derive a theoretical relation between $R_{BLR}$, the size of the broad-emission-line region of active galactic nuclei, and the observed soft X-ray luminosity and spectrum. We show that in addition to the well known $R_{BLR}\sim L^{1/2}$…
A generic toy model of a cooling neutron star (NS) is used to analyze cooling of NSs with nucleon and exotic composition of the cores. The model contains the parameters which specify the levels of slow and enhanced neutrino emission as well…
We study the multiwavelength properties of an optically selected sample of Low Ionization Nuclear Emission-line Regions (LINERs), in an attempt to determine the accretion mechanism powering their central engine. We show how their X-ray…
Type-2 Low-ionization Narrow Emission-line Regions (LINERs) have been optically classified with the Palomar data as not presenting a broad component in the Balmer emission lines associated to the Broad Line Region (BLR) of the Active…
The nulling interferometers proposed to study planets around other stars are generally well suited for studying small-scale structures surrounding other bright pointlike objects such as the nuclei of active galaxies. Conventional…
The Baldwin Effect, a negative correlation between emission-line equivalent width and luminosity in active galactic nuclei, is still of interest as a diagnostic of accretion physics nearly thirty years after its discovery. This review…
Since the discovery of active galactic nuclei (AGN) and their subclasses, a unification scheme of AGN has been long sought. Orientation-based unified models predict that some of the diversity within AGN subclasses can be explained by the…
We have compiled a large sample of low-redshift active galactic nuclei (AGN) identified via their emission line characteristics from the spectroscopic data of the Sloan Digital Sky Survey. Since emission lines are often contaminated by…