Gas inflows towards the nucleus of the Seyfert 2 galaxy NGC 1667

Abstract

We use optical spectra from the inner 2 × 3 kpc 2 of the Seyfert 2 galaxy NGC 1667, obtained with the GMOS integral field spectrograph on the Gemini South telescope at a spatial resolution of ≈ 240 pc, to assess the feeding and feedback processes in this nearby AGN. We have identified two gaseous kinematical components in the emission line profiles: a broader component (σ ≈ 400 km s −1 ) which is observed in the inner 1-2 ′′ and a narrower component (σ ≈ 200 km s −1 ) which is present over the entire field-ofview. We identify the broader component as due to an unresolved nuclear outflow. The narrower component velocity field shows strong isovelocity twists relative to a rotation pattern, implying the presence of strong non-circular motions. The subtraction of a rotational model reveals that these twists are caused by outflowing gas in the inner ≈ 1 ′′ , and by inflows associated with two spiral arms at larger radii. We calculate an ionized gas mass outflow rate ofṀ out ≈ 0.16 M ⊙ yr −1 . We calculate the net gas mass flow rate across a series of concentric rings, obtaining a maximum mass inflow rate in ionized gas of ≈ 2.8 M ⊙ year −1 at 800 pc from the nucleus, which is two orders of magnitude larger than the accretion rate necessary to power this AGN. However, as the mass inflow rate decreases at smaller radii, most of the gas probably will not reach the AGN, but accumulate in the inner few hundred parsecs. This will create a reservoir of gas that can trigger the formation of new stars.

Observational constraints on the feeding of supermassive black holes

“…One such case is that of the galaxy NGC 7213 [205], hosting a LINER/Seyfert 1 nucleus, that shows velocity residuals that imply inflows in nuclear spirals seen in a structure map of the optical HST F606W image of the inner few hundred pcs of the galaxy. Other similar cases include the Seyfert galaxies NGC 1667 [206], NGC 1358 [207], and LINERs NGC 1097 [143], M81 [208] and NGC 6951 [209]. In the case of the Seyfert 2 galaxy NGC 3081 [210], gas inflows have been observed along a nuclear bar.…”

“…Measured versus toy model kinematics of the inner kiloparsec of NGC 1667[206], showing:(a) measured gas velocity field, showing velocities according to the color bar in units of km s −1 ; spatial scale is ≈ 300 pc/ ; (b) toy model velocity field combining inflow in spiral shocks with rotation (plus a compact outflow at the nucleus); contours in panels (a) and (b) are equally spaced and range from −200 to 200 km s −1 ; (c) measured gas velocities after subtraction of the rotation component showing only the residual inflows (plus compact outflow), that can be compared with the (d) inflow (plus compact outflow) component of the toy model; contours in panels (c) and (d) are equally spaced and range from −50 to 50 km s −1 . The dashed line shows the line of nodes of the rotation component, and the near and far sides are identified in panel (a).…”

Nuclear kinematics in nearby AGN – I. An ALMA perspective on the morphology and kinematics of the molecular CO(2–1) emission

“…The nuclear radio emission of the galaxy at 8.4 GHz is weak (∼ 7.5 mJy) with no distinct features but a diffuse emission around the galaxy. The optical IFU observations by Schnorr-Müller et al (2017) reveal complex morphology with two kinematic components of σ ≈ 200 and σ ≈ 400 km s −1 over the entire field of view and the inner 2 respectively.…”

AGNIFS survey of local AGN: GMOS-IFU data and outflows in 30 sources

“…In order to be able to resolve the inner kpc of moderately active galaxies, our group AGNIFS (AGN Integral Field Spectroscopy) has observed over the years several AGN hosts using Gemini IFS in the optical (e.g. Fathi et al 2006;Storchi-Bergmann et al 2007; Barbosa et al 2009;Schnorr-Müller et al 2014a;Lena et al 2015;Schnorr-Müller et al 2016, 2017aBrum et al 2017;Slater et al 2018;Freitas et al 2018;Humire et al 2018;Muñoz-Vergara et al 2019;Soto-Pinto et al 2019) and in the near-IR (Storchi-Bergmann et al 2009, 2010Riffel et al 2017Riffel et al , 2018Schönell et al 2019). While we have so far focused on individual galaxies, in this paper we present data for 30 objects observed in the optical using the Gemini Multi-Object Spectrograph Integral Field Unit (GMOS-IFU).…”