posted on 2018-08-15, 15:56authored byGene C. K. Leung, Alison L. Coil, Mojegan Azadi, James Aird, Alice Shapley, Mariska Kriek, Bahram Mobasher, Naveen Reddy, Brian Siana, William R. Freeman, Sedona H. Price, Ryan L. Sanders, Irene Shivaei
Using observations from the first 2 yr of the MOSFIRE Deep Evolution Field (MOSDEF) survey, we study 13
active galactic nucleus (AGN) driven outflows detected from a sample of 67 X-ray, IR, and/or optically selected
AGNs at z ~ 2. The AGNs have bolometric luminosities of ~ 10^44 - 10^46 erg s^-1 , including both quasars and
moderate-luminosity AGNs. We detect blueshifted, ionized gas outflows in the Hβ, [O III], Hα, and/or [N II]
emission lines of 19% of the AGNs, while only 1.8% of the MOSDEF galaxies have similarly detected outflows.
The outflow velocities span ∼300 to 1000 km s^−1. Eight of the 13 outflows are spatially extended on similar scales
to the host galaxies, with spatial extents of 2.5–11.0 kpc. Outflows are detected uniformly across the star-forming
main sequence, showing little trend with the host galaxy star formation rate. Line ratio diagnostics indicate that the
outflowing gas is photoionized by the AGNs. We do not find evidence for positive AGN feedback, in either our
small MOSDEF sample or a much larger Sloan Digital Sky Survey sample, using the BPT diagram. Given that a
galaxy with an AGN is 10 times more likely to have a detected outflow, the outflowing gas is photoionized by the
AGNs, and estimates of the mass and energy outflow rates indicate that stellar feedback is insufficient to drive at
least some of these outflows; they are very likely to be AGN driven. The outflows have mass-loading factors of the
order of unity, suggesting that they help regulate star formation in their host galaxies, though they may be
insufficient to fully quench it.
Funding
This work would not have been possible without the 3D-HST Collaboration, which provided us with the spectroscopic and photometric catalogs used to select our targets and to derive stellar population parameters. This work is partially supported by NSF CAREER grant 1055081, awarded to A. Coil. Funding for the MOSDEF survey is provided by NSF AAG grants AST-1312780, 1312547, 1312764, and 1313171 and archival grant AR-13907, provided by NASA through a grant from the Space Telescope Science Institute. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain.
History
Citation
Astrophysical Journal, 2017, 849, pp. 48-48
Author affiliation
/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy