2018/09/11 by David R. Law, Charles C. Steidel, Yuguang Chen +3
Physics and Astronomy · #Active galactic nucleus #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Emission spectrum #Galaxies: Formation, Evolution, Phenomena #Galaxy #Ionization #Population #Redshift #Spectroscopy #Star formation #astro-ph.GA
paper · pdf · doi:10.3847/1538-4357/aae156
33 pages, 18 figures. Accepted for publication in ApJ
arxiv created 2018/09/11 · openalex created_date 2018/09/27 · openalex publication_date 2018/10/18 · arxiv updated 2018/11/14 · openalex updated_date 2026/08/05
Abstract We present Keck/OSIRIS laser guide-star assisted adaptive optics (LGSAO) integral-field spectroscopy of [O iii ] λ 5007 nebular emission from 12 galaxies hosting optically faint ( = 20–25; erg s −1 ) active galactic nuclei (AGNs) at redshift z ∼ 2–3. In combination with deep Hubble Space Telescope Wide Field Camera 3 ( HST /WFC3) rest-frame optical imaging, Keck/MOSFIRE rest-optical spectroscopy, and Keck/KCWI rest-UV integral-field spectroscopy, we demonstrate that both the continuum and emission-line structures of these sources exhibit a wide range of morphologies, from compact, isolated point sources to double-AGN merging systems with extensive ∼50 kpc tidal tails. One of the 12 galaxies previously known to exhibit a proximate damped Ly α system coincident in redshift with the galaxy shows evidence for both an extended [O iii ] narrow-line emission region and spatially offset Ly α emission (with morphologically distinct blueshifted and redshifted components) indicative of large-scale gas flows photoionized by the central AGN. We do not find widespread evidence of star formation in the host galaxies surrounding these AGNs; the [O iii ] velocity dispersions tend to be high ( σ = 100–500 ), the continuum morphologies are much more compact than a mass-matched star-forming comparison sample, and the diagnostic nebular emission-line ratios are dominated by an AGN-like ionizing spectrum. The sample is most consistent with a population of AGNs that radiate at approximately their Eddington limit and photoionize extended [O iii ] nebulae whose characteristic sizes scale approximately as the square root of the AGN luminosity.