Related papers: Tests of a Structure for Quasars
We introduce a phenomenological investigation of the evolution and large scale distribution of quasars using a modified version of the Field and Colgate gravitational contraction model for proto-galaxies. By studying the distribution of…
Microvariations probe the physics and internal structure of quasars. Unpredictability and small flux variations make this phenomenon elusive and difficult to detect. Variance based probes such as the C and F tests, or a combination of both,…
Seyfert galaxies and quasars were first discovered through optical and radio techniques, but in recent years high-energy emission, that can penetrate central gas and dust, has become essentially the defining characteristic of an AGN. AGNs…
Theoretical atmosphere models provide the basis for a variety of applications in astronomy. In simplified one-dimensional (1D) atmosphere models, convection is usually treated with the mixing length theory despite its well-known…
This article reviews and discusses 1) the discovery and early work on the evolution of quasars and AGNs, 2) the different techniques used to find quasars and their suitability for evolutionary studies, 3) the current status of our knowledge…
A brief review of the search for variation of the fine structure constant in quasar absorption spectra is presented. Special consideration is given to the role of atomic calculations in the analysis of the observed data. A range of methods…
High resolution spectra of quasar absorption systems provide the best constraints on temporal or spatial changes of fundamental constants in the early universe. An important systematic that has never before been quantified concerns model…
The constraints on the models for the structure formation arising from various cosmological observations at different length scales are reviewed. The status of different models for structure formation is examined critically in the light of…
This paper proposes a simple, empirically derived, unifying structure for the inner regions of quasars. This structure is constructed to explain the broad absorption line (BAL) regions, the narrow `associated' ultraviolet and X-ray warm…
This review describes recent developments related to the unified model of active galactic nuclei (AGN). It focuses on new ideas about the origin and properties of the central obscurer (torus), and the connection with its surrounding. The…
This study focuses on high-redshift, z > 3, quasars where resolved X-ray jets remain underexplored in comparison to nearby sources. Building upon previous work, we identify and confirm extended kpc-scale jets emission in two quasars…
The participants in this meeting are almost all carrying out the hard work of making many different types of AGN surveys. Since it's so much easier to criticize other people's work than to do actual work myself, I'll just present some…
Quasars are notable for the luminous power they emit across decades in frequency from the far-infrared through hard X-rays; emission at different frequencies emerges from physical scales ranging from AUs to parsecs. Each wavelength regime…
Theoretical predictions for the ensemble quasar structure function are tested using multi-epoch observations of Stripe 82 collected by the Sloan Digital Sky Survey. We reanalyze the entire available volume of the g-band imaging data using…
In this paper I investigate the possibility to test Einstein's equations with observations of cosmological large scale structure. I first show that we have not tested the equations in observations concerning only the homogeneous and…
Uranus and Neptune are still poorly understood. Their gravitational fields, rotation periods, atmosphere dynamics, and internal structures are not well determined. In this paper we present empirical structure models of Uranus and Neptune…
This talk discusses the unified X-ray/UV absorption models in AGN. I will first review the models and discuss how they offer an unique opportunity to probe the near nuclear environment of AGNs. Recently, however, the validity of these…
Models for the formation of galaxies and clusters of galaxies require strong feedback in order to explain the observed properties of these systems. We investigate whether such feedback has observational consequences for the intergalactic…
In my review of jet phenomena in quasars, I focus on the following questions: How powerful are jets in radio-loud quasars? What is their composition? How are they launched? And why, in most quasars, are they so weak? I demonstrate the…
The orientation-based unification model proposes that radio-loud quasars and radio galaxies are the same objects observed at different angles. A key prediction of this model is that the quasars are seen at smaller angles to the line of…