Gemini NIFS survey of feeding and feedback processes in nearby active galaxies – I. Stellar kinematics

Abstract

We use the Gemini Near-Infrared Integral Field Spectrograph (NIFS) to map the stellar kinematics of the inner few hundred parsecs of a sample of 16 nearby Seyfert galaxies, at a spatial resolution of tens of parsecs and spectral resolution of 40 km s −1. We find that the line-of-sight (LOS) velocity fields for most galaxies are well reproduced by rotating disc models. The kinematic position angle (PA) derived for the LOS velocity field is consistent with the large-scale photometric PA. The residual velocities are correlated with the hard X-ray luminosity, suggesting that more luminous active galactic nuclei have a larger impact in the surrounding stellar dynamics. The central velocity dispersion values are usually higher than the rotation velocity amplitude, what we attribute to the strong contribution of bulge kinematics in these inner regions. For 50 per cent of the galaxies, we find an inverse correlation between the velocities and the h 3 Gauss-Hermitte moment, implying red wings in the blueshifted side and blue wings in the redshifted side of the velocity field, attributed to the movement of the bulge stars lagging the rotation. Two of the 16 galaxies (NGC 5899 and Mrk 1066) show an S-shape zero velocity line, attributed to the gravitational potential of a nuclear bar. Velocity dispersion (σ) maps show rings of low-σ values (∼50-80 km s −1) for four objects and 'patches' of low σ for six galaxies at 150-250 pc from the nucleus, attributed to young/ intermediate age stellar populations.

Gemini NIFS survey of feeding and feedback in nearby active galaxies – III. Ionized versus warm molecular gas masses and distributions

“…The kinematics major axis PA ≈ 125 • was determined from the V LOS fields (Fig. 2), with a value close to that obtained by Riffel et al (2017) for the stellar kinematics of ≈ 130 • . The velocity amplitude observed for [Fe ii] and Paβ, of ≈ 150 km s −1 is much higher than that for H 2 , of only ≈ 50 km s −1 .…”

“…7) is reported to be in a pair and presents an optical Seyfert 2 spectrum (de Vaucouleurs et al 1991). The stellar kinematics derived by Riffel et al (2017) gives a PA ≈ 24 • , that is somewhat distinct from that obtained by us for the molecular gas (Paper B), of ≈ 4 • . The kinematics of the ionized gas is very different from that of the molecular gas ( Fig.…”

Chemical abundances of Seyfert 2 AGNs – II. N2 metallicity calibration based on SDSS

“…This result is supported by recent spatially resolved observational studies of Seyfert 2 nuclei, in which the presence of gas outflows with velocity of the order of 100-300 km s −1 have been found (e.g. Riffel et al 2017Riffel et al , 2018. Moreover, the Te-problem can also be originated due to the use of an unappropriate calculation of the Ionization Correction Factor (ICF) for oxygen in AGNs (Pérez-Montero et al 2019;Dors et al 2020).…”

A panchromatic spatially resolved study of the inner 500 pc of NGC 1052 – I. Stellar population

“…They also found that there is a sharp cusp in the velocity dispersion close to the nucleus, presumably within the zone of influence of the central black hole. These results were later confirmed by Riffel et al (2017) using NIR data, which also found a centrally peaked σ distribution and a rotation around the photometric minor axis. Besides that, they found an anti-correlation between the h 3 momentum and the velocity field, which they interpreted as due do the contribution of stars rotating slower than those in the galaxy disk, probably due to motion in the galaxy bulge.…”