Lyman Alpha Emitters (LAEs) are usually thought to be powered by star formation. It has been recently reported that a fraction of LAEs at redshift z~3-4 hosts an Active Galactic Nuclei (AGN). If an AGN is present it could be obscured and undetectable in X-rays, but yet dominate the Lya luminosity. We examine the properties of these AGN-powered LAEs at high redshift (z>=6) using radiative transfer cosmological simulations and obtain a reliable criterion to identify them from their observed \Lya line and surface brightness. We find that these sources should have: (a) negative line weighted skewness, S_w <0, and (b) surface brightness profiles FWHM >= 1.5". This parameter space cannot be populated by starburst LAEs. Thus, LAEs satisfying this criterion would be strong candidates for the presence of a hidden AGN powering their luminosity.
@article{arxiv.1302.3353,
title = {Identifying Lyman Alpha Emitters powered by AGNs},
author = {Sunghye Baek and Andrea Ferrara},
journal= {arXiv preprint arXiv:1302.3353},
year = {2015}
}
Comments
6 pages, 5 figures, accepted for publication by MNRASL