Long Term Profile Variability of Double-Peaked Emission Lines in AGNs
Abstract
An increasing number of AGNs exhibit broad, double-peaked Balmer emission lines, which are thought to arise from the outer regions of the accretion disk which fuels the AGN. The line profiles are observed to vary on a characteristic timescales of 5-10 years. The variability is not a reverberation effect; it is a manifestation of physical changes in the disk. Our group has monitored a set of 20 double-peaked emitters for the past 8 years (longer for some objects). Here, we characterize the variability of the double-peaked H alpha line profiles in five objects from our sample. By experimenting with simple models, we find that disks with a single precessing spiral arm are able to reproduce many of the variability trends that are seen in the data.
Cite
@article{arxiv.astro-ph/0309624,
title = {Long Term Profile Variability of Double-Peaked Emission Lines in AGNs},
author = {Karen T. Lewis and Michael Eracleous and Jules P. Halpern and Thaisa Storchi-Bergmann},
journal= {arXiv preprint arXiv:astro-ph/0309624},
year = {2007}
}
Comments
4 pages, 1 figure, uses newpasp.sty To appear in "AGN Physics with the Sload Digital Sky Survey" Princeton, July 27-30, 2003