Gravitational lensing of quasars
Author(s)
Bibliographic Information
Gravitational lensing of quasars
EPFL Press, c2012
- hbk.
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Note
Includes bibliography and index
Description and Table of Contents
Description
The universe, in all its richness, diversity and complexity, is populated by a myriad of intriguing celestial objects. Among the most exotic of them are gravitationally lensed quasars. A quasar is an extremely bright nucleus of a galaxy, and when such an object is gravitationally lensed, multiple images of the quasar are produced - this phenomenon of cosmic mirage can provide invaluable insights on burning questions, such as the nature of dark matter and dark energy.
After presenting the basics of modern cosmology, GravItational Lensing of Quasars describes active galactic nuclei, the theory of gravitational lensing, and presents a particular numerical technique to improve the resolution of astronomical data. The book then enters the heart of the subject with the description of important applica- tions of gravitational lensing of quasars, such as the measurement of the famous Hubble constant, the determination of the dark matter distribution in galaxies, and the observation of the mysterious inner parts of quasars with much higher resolutions than those accessible with the largest telescopes. This book gives an overview of the current status of research in the field of gravitationally lensed quasars. It also gives some insights about the way this research is conducted in practice, and presents real data and results obtained with several high-technology instruments of the Very Large Telescope of the European Southern Observatory.
Table of Contents
Foreword
Introduction
Outline
Basics of modern cosmology
The cosmological principle
The Friedmann-Lemaitre-Robertson-Walker metric
The Hubble constant
Cosmological redshift
Friedmann equations
Energy components of Universe
Critical density
Density parameters
Cosmological distances
Observational cosmology
The concordance model
Unanswered questions
Active galactic nuclei
Classification scheme
Unified scheme
Radius-luminosity relationship
Standard thin accretion disk model
Problems with the standard thin accretion disk model
Gravitational lensing
Historical background
Lens equation
Deflection angle
Deflection potential
Arrival time and Fermat's principle
Time delays and the Hubble constant
Images and magnification of a lensed source
Properties of ordinary images
Critical curves and caustics
The mass-sheet degeneracy
Models of gravitational lenses
Searches for new gravitationally lensed quasars
Deconvolution
Spatial deconvolution
Time delays and the Hubble constant
Introduction
Observational and theoretical challenges
Determination of the optimal monitoring strategy
Methods to measure time delays
COSMOGRAIL
Discussion
Redshift of lensing galaxies
Introduction
Spectroscopy with the Very Large Telescope
Lens redshifts and dark energy
Discussion
Microlensing: a natural telescope
Introduction
Particularities of microlensing
First microlensing techniques
Applications of quasar microlensing
The Einstein Cross QSO 2237+0305
Spectrophotometric monitoring of QSO 2237+0305
Energy profile of the accretion disk
Discussion
Dynamics versus gravitational lensing
Introduction
Integral-field spectroscopy with FLAMES
Integral-field spectroscopy with SINFONI
Long-slit spectroscopy with FORS2
Dynamical models of lensing galaxies
Discussion
General conclusions and outlook
Bibliography
by "Nielsen BookData"