Related papers: Chemical Abundances in Active Galaxies

We have collected an heterogeneous sample of galaxies at redshifts 0.001<z<3.35 with the aim of exploring the evolution of the physical parameters and of the element abundances calculated by modelling the observed spectra. The evolution…

In order to perform a more complete census of active galactic nuclei (AGN) in the local Universe, we investigate the use of the HeII~$\lambda 4685$ emission line diagnostic diagram by Shirazi & Brinchmann (2012) in addition to the standard…

The emission line luminosity function of active galactic nuclei (AGN) is measured from about 3000 AGN included in the main galaxy sample of the Sloan Digital Sky Survey within a redshift range of $0<z<0.15$. The $\Ha$ and [OIII]$\lambda…

We study the relation between nitrogen and oxygen abundances as a function of metallicity for a sample of emission-line objects for which a direct measurement of the metallicity has been possible. This sample is representative of the very…

We present 6.5-meter MMT spectrophotometry of 20 H II regions in 13 extremely metal-poor emission-line galaxies selected from the Data Release 5 of the Sloan Digital Sky Survey to have [O III] 4959/Hbeta < 1 and [N II] 6583/Hbeta < 0.05.…

Spectra of extranuclear clouds within the ionization cone of Circinus galaxy are presented and modelled assuming photoionization by the Seyfert 2 nucleus but no preconceived assumption concerning the spectral shape of the ionizing AGN…

Low luminosity active galactic nuclei (LLAGN) probe accretion physics in the low Eddington regime and can provide additional clues about galaxy evolution. AGN variability is ubiquitous and thus provides a reliable tool for finding AGN. We…

We select 947 star-forming galaxies from SDSS-DR7 with [O~{\sc iii}]$\lambda$4363 emission lines detected at a signal-to-noise {ratio }larger than 5$\sigma$. Their electron temperatures and direct oxygen abundances are {then }determined.…

Using the wide multi-band photometry available in the COSMOS field we explore the host galaxy properties of a large sample of Active Galactic Nuclei (AGN) obtained by combining X-ray and optical spectroscopic selections. Based on a careful…

We study the environment of active galaxies and compare it with that of star forming and normal galaxies. We extracted from the Fourth Data Release (DR4) of the Sloan Digitaly Sky Survey (SDSS) the galaxies in the redshift range 0.05 \le z…

We have applied ClassX, an oblique decision tree classifier optimized for astronomical analysis, to the homogeneous multicolor imaging data base of the Sloan Digital Sky Survey (SDSS), training the software on subsets of SDSS objects whose…

We present the largest direct-method abundance catalogue of galaxies to date, containing measurements of 49$\,$959 star-forming galaxies at $z < 0.96$ from DESI Data Release 2. By directly measuring electron temperatures across multiple…

Using integrated spectra for two gravitationally lensed galaxies from the JWST TEMPLATES Early Release Science program, we analyze faint auroral lines, which provide direct measurements of the gas-phase chemical abundance. For the brighter…

Galaxy-galaxy interactions are predicted to cause gas inflows leading to enhanced nuclear star formation. In this paper we test the further prediction that the gas inflows lead to enhanced accretion onto the central supermassive black hole,…

This paper presents a study of the local radio source population, by cross-comparing the data from the first data release (DR1) of the LOFAR Two-Metre Sky Survey (LoTSS) with the Sloan Digital Sky Survey (SDSS) DR7 main galaxy spectroscopic…

We select a sample of 1,437 active galactic nuclei (AGN) from the catalog of the Sloan Digital Sky Survey (SDSS) galaxy properties from the Portsmouth group by detection of the high-ionization [Ne V] 3426 \r{A} emission line. We compare the…

We use 317,000 emission-line galaxies from the Sloan Digital Sky Survey to investigate line-ratio selection of active galactic nuclei (AGNs). In particular, we demonstrate that "star formation dilution" by HII regions causes a significant…

The ``AGN Physics with the Sloan Digital Sky Survey'' conference was held at Princeton University in July 2003 to bring together groups working inside and outside of the SDSS collaboration at radio through X-ray wavelengths to discuss the…

We present the host galaxy molecular gas properties of a sample of 213 nearby (0.01<z< 0.05) hard X-ray selected AGN galaxies, drawn from the 70-month catalog of Swift-BAT, with 200 new CO(2-1) line measurements obtained with the JCMT and…

We aimed to study the molecular composition of the interstellar medium (ISM) surrounding an Active Galactic Nucleus (AGN), by making an inventory of molecular species and their abundances, as well as to establish a chemical differentiation…