No Evidence for Feedback: Unexceptional Low-ionization Winds in Host Galaxies of Low Luminosity Active Galactic Nuclei at Redshift z ∼ 1

Abstract

We study winds in 12 X-ray AGN host galaxies at z ∼ 1. We find, using the low-ionization Fe II λ2586 absorption in the stacked spectra, that the probability distribution function (PDF) of the centroid velocity shift in AGN has a median, 16th and 84th percentiles of (-87, -251, +86) km s −1 respectively. The PDF of the velocity dispersion in AGN has a median, 84th and 16th percentile of (139, 253, 52) km s −1 respectively. The centroid velocity and the velocity dispersions are obtained from a two component (ISM+wind) absorption line model. The equivalent width PDF of the outflow in AGN has median, 84th and 16th percentiles of (0.4, 0.8, 0.1) Å. There is a strong ISM component in Fe II λ2586 absorption with (1.2, 1.5, 0.8) Å, implying presence of substantial amount cold gas in the host galaxies. For comparison, star-forming and X-ray undetected galaxies at a similar redshift, matched roughly in stellar mass and galaxy inclination, have a centroid velocity PDF with percentiles of (-74, -258, +90) km s −1 , and a velocity dispersion PDF percentiles of (150, 259, 57) km s −1 . Thus, winds in the AGN are similar to star-formation-driven winds, and are too weak to escape and expel substantial cool gas from galaxies. Our sample doubles the previous sample of AGN studied at z ∼ 0.5 and extends the analysis to z ∼ 1. A joint reanalysis of the z ∼ 0.5 AGN sample and our sample yields consistent results to the measurements above.

Cool outflows in galaxies and their implications

“…17 Weiner et al 2009;Rubin et al 2014). "Relic" outflows with typical velocities ∼ 200 km s −1 are often seen in post-starburst galaxies (Coil et al 2011;Yesuf et al 2017), although in exceptional cases, possibly due to recent quasar activity or extremely compact optically obscured starbursts, these winds reach velocities in excess of ∼ 1000 km s −1 (Tremonti et al 2007;Diamond-Stanic et al 2012;Geach et al 2014;Sell et al 2014;Maltby et al 2019). In general, low-luminosity AGN do not have a strong influence on the velocities and equivalent widths of these winds (Coil et al 2011;Yesuf et al 2017).…”

Quasar-mode Feedback in Nearby Type 1 Quasars: Ubiquitous Kiloparsec-scale Outflows and Correlations with Black Hole Properties

“…Though such outflows are harder to detect at high z than at low z, observations are beginning to suggest that quasar-driven winds could be common at the epochs of peak star formation and BH accretion (Perna et al 2015;Brusa et al 2015;Carniani et al 2015Carniani et al , 2016Leung et al 2017). At high z but low AGN luminosity, the impact of winds may be less, though the data are sparse (Yesuf et al 2017).…”

Signatures of inflowing gas in red geyser galaxies hosting radio-AGN

“…The presence of warm ionized gas suggests the possibility that red geysers also host cooler gas reservoirs in the interstellar medium (ISM). Cool gas in the form of outflows are routinely observed in ultra luminous infrared galaxies, star forming and post-starburst galaxies (Cazzoli et al 2016;Rubin et al 2012Rubin et al , 2014Weiner et al 2009;Alatalo et al 2016;Martin et al 2005;Chen et al 2010;Yesuf et al 2017;Roberts-Borsani & Saintonge 2019;Coil et al 2011;Rupke 2018;Veilleux et al 2020). Indeed, Cheung et al (2016) studied signatures of cool material traced by NaD absorption in their prototypical red geyser.…”