Hubble Space Telescope Observations of Extended [O iii]λ 5007 Emission in Nearby QSO2s: New Constraints on AGN Host Galaxy Interaction

Abstract

We present a Hubble Space Telescope (HST) survey of extended [O III] λ5007 emission for a sample of 12 nearby (z < 0.12), luminous Type 2 quasars (QSO2s), which we use to measure the extent and kinematics of their AGN-ionized gas. We find the size of the observed [O III] regions scale with luminosity in comparison to nearby, less luminous Seyfert galaxies and radially outflowing kinematics to exist in all targets. We report an average maximum outflow radius of ∼600 pc, with gas continuing to be kinematically influenced by the central AGN out to an average radius of ∼ 1130 pc. These findings question the effectiveness of AGN being capable of clearing material from their host bulge in the nearby universe and suggest that disruption of gas by AGN activity may prevent star formation without requiring evacuation. Additionally, we find a dichotomy in our targets when comparing [O III] radial extent and nuclear FWHM, where QSO2s with compact [O III] morphologies typically possess broader nuclear emission-lines.

A Dissection of Spatially Resolved AGN Feedback across the Electromagnetic Spectrum

“…The central field of view is largely redshifted north of the nucleus, with bright flux profiles corresponding to the bright structures observed in imaging likely due to adjacent molecular gas lanes being ionized by the AGN (Fischer et al 2017). South of the nucleus is a low-flux region that exhibits blueshifted velocities, adjacent to a bright gas lane which exhibits generally systemic veloc- [O III] λ5007 kinematic measurements in 2MASX J0423 from SNIFS IFU observations.…”

“…were measured in each spaxel of our SNIFS data cubes by fitting Gaussians in an automated routine, with example fits to spectra shown in Figures 2. Our fitting process, previously discussed in depth in Fischer et al (2017), uses the Importance Nested Sampling algorithm as implemented in the MultiNest library (Feroz & Hobson 2008;Feroz et al 2009Feroz et al , 2013Buchner et al 2014) to compute the logarithm of the evidence, lnZ, for models containing a continuum plus zero to two Gaussian components per emission line. When comparing two models, i.e.…”

“…Using a method similar to the one used by Fischer et al (2017) for Mrk 573, HST WFPC2/PC F814W imaging of 2MASX J0423 was decomposed using GALFIT version 3.0.5 (Peng et al 2002(Peng et al , 2010 in order to measure enclosed mass and calculate gravitational deceleration in the galaxy as function of radius. We find that the best fitting model is composed of three Sérsic components with parameters described in Table 1.…”

“…In order to determine whether the emission-line gas can be radiatively accelerated in situ, we used the radiationgravity formalism detailed in Das et al (2007) and Fischer et al (2017). Assuming an azimuthally symmetric distribution, velocity as a function of radial distance, v(r), in units of km s −1 and pc, can be written as:…”

“…An important complement to this approach is studying the detailed interaction of an AGN and its host galaxy in individual objects. Recently, we analyzed kinematics in the luminous, nearby (z=0.017) Seyfert 2 galaxy Mrk 573 (Fischer et al 2017), where we found the AGN-ionized gas morphology to be consistent with an intersection between spiral arms in the host disk and ionizing radiation from the central engine. Dust lanes rotating in the host disk, traced by molecular hydrogen emission, were found to connect regions of ionized gas from outside of the biconical AGN radiation field, suggesting that kinematics of the outflowing ionized gas in the narrow-line region (NLR) of Mrk 573 are due to in situ acceleration of material originating in the host disk via radiative driving by the AGN, until radiative driving is no longer able to disrupt the rotational motion of the spiral arms, forming the Extended NLR (ENLR).…”