The AGN nature of LINER nuclear sources

Properties of LINERs

Massive ionized outflows in quasars

The most luminous quasars in the Hamburg- ESO (HE) survey show, at a high prevalence, CIV λ1549 and [OIII]λλ4959,5007 emission line profiles with high-amplitude blueshifts which indicate outflows occurring over a wide range of spatial scales. We found evidence in favor of the nuclear origin of the outflows diagnosed by [OIII]λλ 4959,5007. The derived ionized gas mass, kinetic power, and radiation thrust are extremely high, and suggest widespread feedback on the host galaxies of very luminous quasars, at cosmic epochs between 2 and 6 Gyr from the Big Bang

Metal Content in Relativistically Jetted and Radio-Quiet Quasars in the Main Sequence Context

The optical and UV properties of radio-quiet (RQ) and radio-loud (RL, relativistically “jetted”) active galactic nuclei (AGN) are known to differ markedly; however, it is still unclear what is due to a sample selection and what is associated with intrinsic differences in the inner workings of their emitting regions. Chemical composition is an important parameter related to the trends of the quasar main sequence. Recent works suggest that in addition to physical properties such as density, column density, and ionization level, strong Feii emitters require very high metal content. Little is known, however, about the chemical composition of jetted radio-loud sources. In this short note, we present a pilot analysis of the chemical composition of low-z radio-loud and radio-quiet quasars. Optical and UV spectra from ground and space were combined to allow for precise measurements of metallicity-sensitive diagnostic ratios. The comparison between radio-quiet and radio-loud was carried out for sources in the same domain of the Eigenvector 1/main sequence parameter space. Arrays of dedicated photo-ionization simulations with the input of appropriate spectral energy distributions indicate that metallicity is sub-solar for RL AGN, and slightly sub-solar or around solar for RQ AGN. The metal content of the broad line-emitting region likely reflects a similar enrichment story for both classes of AGN not involving recent circum-nuclear or nuclear starbursts

Quasars as cosmological standar candles

Using QSO as distance indicator

Quasars: From the Physics of Line Formation to Cosmology

Quasars accreting matter at very high rates (known as extreme Population A (xA) or super-Eddington accreting massive black holes) provide a new class of distance indicators covering cosmic epochs from the present-day Universe up to less than 1 Gyr from the Big Bang. The very high accretion rate makes it possible that massive black holes hosted in xA quasars can radiate at a stable, extreme luminosity-to-mass ratio. This in turn translates into stable physical and dynamical conditions of the mildly ionized gas in the quasar low-ionization line emitting region. In this contribution, we analyze the main optical and UV spectral properties of extreme Population A quasars that make them easily identifiable in large spectroscopic surveys at low- (z . 1) and intermediate-z (2 . z . 2.6), and the physical conditions that are derived for the formation of their emission lines. Ultimately, the analysis supports the possibility of identifying a virial broadening estimator from low-ionization line widths, and the conceptual validity of the redshift-independent luminosity estimates based on virial broadening for a known luminosity-to-mass ratioP.M. wishes to thank the Scientific Organizing Committee of the Symposium on the Physics of Ionized Gases (SPIG 2018) meeting for inviting the topical lecture on which this paper is based, and acknowledges the Programa de Estancias de Investigación (PREI) No. DGAP/DFA/2192/2018 of Universidad Nacional Autónoma de México (UNAM), where this paper was written. The relevant research is part of the project 176001 “Astrophysical spectroscopy of extragalactic objects” and 176003 “Gravitation and the large scale structure of the Universe” supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia. M.L.M.-A. acknowledges a CONACyT postdoctoral fellowship. A.d.O. and M.L.M.-A. acknowledge financial support from the Spanish Ministry for Economy and Competitiveness through Grant Nos. AYA2013-42227-P and AYA2016-76682-C3-1-P. M.L.M.-A, P.M. and M.D. acknowledge funding from the INAF PRIN-SKA 2017 program 1.05.01.88.04. D.D. and A.N. acknowledge support from CONACyT through Grant No. CB221398. D.D. and C.A.N. are also thankful for the support from Grant No. IN108716 53 PAPIIT, UNAMWe acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)Peer reviewe

A main sequence for quasars

<p>Panoramic view of the Eigenvector 1 formalism for the study of quasars</p