Harrison, C. M., Alexander, D. M., Mullaney, J. R. orcid.org/0000-0002-3126-6712 et al. (7 more authors) (2016) The KMOS AGN Survey at High redshift (KASHz): the prevalence and drivers of ionized outflows in the host galaxies of X-ray AGN. Monthly Notices of the Royal Astronomical Society, 456 (2). pp. 1195-1220. ISSN 0035-8711
Abstract
We present the first results from the KMOS (K-band Multi-Object Spectrograph) AGN (active galactic nuclei) Survey at High redshift (KASHz), a VLT/KMOS integral-field spectroscopic (IFS) survey of z ≳ 0.6 AGN. We present galaxy-integrated spectra of 89 X-ray AGN (L2–10 keV = 1042–1045 erg s−1), for which we observed [O III] (z ≈ 1.1–1.7) or Hα emission (z ≈ 0.6–1.1). The targets have X-ray luminosities representative of the parent AGN population and we explore the emission-line luminosities as a function of X-ray luminosity. For the [O III] targets, ≈50 per cent have ionized gas velocities indicative of gas that is dominated by outflows and/or highly turbulent material (i.e. overall line widths ≳600 km s−1). The most luminous half (i.e. LX > 6 × 1043 erg s−1) have a ≳2 times higher incidence of such velocities. On the basis of our results, we find no evidence that X-ray obscured AGN are more likely to host extreme kinematics than unobscured AGN. Our KASHz sample has a distribution of gas velocities that is consistent with a luminosity-matched sample of z < 0.4 AGN. This implies little evolution in the prevalence of ionized outflows, for a fixed AGN luminosity, despite an order-of-magnitude decrease in average star formation rates over this redshift range. Furthermore, we compare our Hα targets to a redshift-matched sample of star-forming galaxies and despite a similar distribution of Hα luminosities and likely star formation rates, we find extreme ionized gas velocities are up to ≈10 times more prevalent in the AGN-host galaxies. Our results reveal a high prevalence of extreme ionized gas velocities in high-luminosity X-ray AGN and imply that the most powerful ionized outflows in high-redshift galaxies are driven by AGN activity.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2015 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society |
Keywords: | galaxies: active; galaxies: evolution; galaxies: kinematics and dynamics; quasars: emission lines |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 14 Nov 2016 14:37 |
Last Modified: | 14 Nov 2016 14:38 |
Published Version: | http://dx.doi.org/10.1093/mnras/stv2727 |
Status: | Published |
Publisher: | Oxford University Press (OUP): Policy P - Oxford Open Option A |
Refereed: | Yes |
Identification Number: | 10.1093/mnras/stv2727 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:106768 |