2001 PETERSON AGN的光变

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考虑有相对论运动对光变时标的影响。

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Title:		Variability of Active Galactic Nuclei
Authors:		Peterson, B. M.
Publication:		Advanced Lectures on the Starburst-AGN Connection, Proceedings of a conference held in Tonantzintla, Puebla, Mexico, 26-30 June, 2000. Edited by Itziar Aretxaga, Daniel Kunth, and Raúl Mújica. Singapore: World Scientific, 2001., p.3
Publication Date:		00/2001
Origin:		ADS
Bibliographic Code:		2001sac..conf....3P

Abstract

Continuum and emission-line variability of active galactic nuclei provides a powerful probe of microarcsecond scale structures in the central regions of these sources. In this contribution, we review basic concepts and methodologies used in analyzing AGN variability. We develop from first principles the basics of reverberation mapping, and pay special attention to emission-line transfer functions. We discuss application of cross-correlation analysis to AGN light curves. Finally, we provide a short review of recent important results in the field.

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Bibtex entry for this abstract   Preferred format for this abstract (see Preferences) 还有一篇类似的博士论文： · Find Similar Abstracts (with default settings below) · Electronic Refereed Journal Article (HTML) · References in the article · Also-Read Articles (Reads History) · · Translate This Page Title: Multi-frequency time variability of active galactic nuclei Authors: Chatterjee, Ritaban Affiliation: AA(Boston University) Publication: Proquest Dissertations And Theses 2010. Section 0017, Part 0606 171 pages; [Ph.D. dissertation].United States - - Massachusetts: Boston University; 2010. Publication Number: AAT 3382562. Source: DAI-B 70/10, Apr 2010 Publication Date: 00/2010 Origin: UMI Keywords: Time variability, Active galactic nuclei, Blazars, Radio galaxies Comment: Publication Number: AAT 3382562; ISBN: 9781109436013; Advisor: Marscher, Alan P. Bibliographic Code: 2010PhDT.........1C Abstract In an active galactic nucleus (AGN), the central region of a galaxy is brighter than the rest of the galaxy and sometimes ~10,000 times as bright as an average galaxy. The extremely high luminosities of AGNs are thought to be produced by the accretion of matter onto a supermassive black hole (1 million-10 billion solar masses). In many cases AGNs produce two oppositely directed jets of magnetized plasma moving at near-light speed that are luminous over a large range of wavelengths. Understanding the structure and ongoing physical processes of AGNs has important implications in cosmology, galaxy formation theory, black hole physics and other areas of astronomical interest. Due to their large distances, AGNs are not spatially resolved with current and near- future technologies except by radio interferometry. However, we can use time variability, one of the defining properties of AGNs, to probe the location and physical processes related to the emission at resolutions even finer than provided by very long baseline interferometry (VLBI). This dissertation employs extensive multi-frequency monitoring data of the blazar 3C 279 (over >10 years) and the radio galaxies 3C 120 and 3C 111 (>5 years) at X-ray, optical, and radio wavebands, as well as monthly VLBI images. The study develops and applies a set of statistical tools to characterize the time variability of AGNs, including power spectral density (PSD), discrete cross-correlation functions and calculation of their significance. This involves generation of light curves simulated randomly from the previously calculated PSDs. Numerical models of the time variable emission spectrum of the jets and accretion disk-corona system relate the variability to the physics and locations of the various emission regions of the AGN. The analysis leads to the inferences that (1) multiple nonthermal emission zones occur in the jet, (2) acceleration of the highest energy electrons in the jet is often gradual, (3) optical emission from the radio galaxies arises mainly in the accretion disk, and (4) the X-ray emitting hot electrons above the disk lie within about 50 gravitational radii from the black hole. Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)