Phylogenetic Analyses of Quasars and Galaxies

Phylogenetic Analyses of Quasars and Galaxies

Phylogenetic approaches have proven to be useful in astrophysics. We have recently published a Maximum Parsimony (or cladistics) analysis on two samples of 215 and 85 low-z quasars (z < 0.7) which offer a satisfactory coverage of the Eigenvector 1-derived main sequence. Cladistics is not only able to group sources radiating at higher Eddington ratios, to separate radio-quiet (RQ) and radio-loud...

Quasars and their host galaxies

This review attempts to describe developments in the fields of quasar and quasar host galaxies in the past five. In this time period, the Sloan and 2dF quasar surveys have added several tens of thousands of quasars, with Sloan quasars being found to z > 6. Obscured, or partially obscured quasars have begun to be found in significant numbers. Black hole mass estimates for quasars, and our confid...

Looking at quasars through galaxies

Observations of quasars (QSOs) shining through or close to galaxies offer a way to probe the properties of the foreground matter through dust extinction and gravitational lensing. In this paper the feasibility of measuring the dust extinction properties is investigated using the backlitting of QSOs. We test our method to search for QSOs affected by intervening extinction, by matching the coordi...

Active Galaxies and Quasars , 2010 - 2020

Local Ultraluminous Infrared Galaxies and Quasars

This paper reviews the recent results from a comprehensive investigation of the most luminous mergers in the local universe, the ultraluminous infrared galaxies (ULIRGs) and the quasars. First, the frequency of occurrence and importance of black hole driven nuclear activity in ULIRGs are discussed using the latest sets of optical, near-infrared, mid-infrared, and X-ray spectra on these objects....