The Ionizing Continuum of Quasars
Abstract
The ionizing continuum shape of quasars is generally not directly observable, but indirect arguments, based on photoionization models and thin accretion disk models suggest that it should peak in the extreme UV, and drop steeply into the soft X-ray regime. However, recent observations of very soft X-ray emission in low z quasars, and far UV emission of high z quasars, suggest that the ionizing continuum of quasars does not peak in the extreme UV, and may extend as a single power law from ~1000 A to ~1 keV. If true, that has interesting implications for photoionization models and for accretion disk models. The proposed revised continuum shape will be tested directly in the near future with FUSE.
Cite
@article{arxiv.astro-ph/9810227,
title = {The Ionizing Continuum of Quasars},
author = {Ari Laor},
journal= {arXiv preprint arXiv:astro-ph/9810227},
year = {2007}
}
Comments
10 pages, to appear in the proceedings of the meeting on "Quasars as Standard Candles for Cosmology" held on May 18-22, 1998, at La Serena, Chile. To be published by ASP, editor G. Ferland