Feeding and Feedback in nearby AGN from Integral Field Spectroscopy

I report results of recent integral field spectroscopy of the inner few hundred parsecs (pc) around nearby Active Galactic Nuclei (AGN) at a sampling of a few pc, obtained with the Gemini Telescopes. In the lowest activity AGNs, it is possible to observe inflows in ionized gas along nuclear spirals and filaments. In more luminous AGN inflows have been observed also in hot molecular gas (H_2) emission in the near-IR. In most cases the H_2 kinematics is dominated by circular rotation in the plane around the nucleus, tracing the AGN feeding. The ionized gas, on the other hand, traces the AGN feedback. Its kinematics shows two components: (1) one originating in the plane, and dominated by circular rotation; (2) another outflowing along the Narrow-Line Region (NLR) whose flux distribution and kinematics frequently correlate with structures seen in radio maps. Mass outflow rates along the NLR range from 10^-2 to 1 M_sun yr^-1, corresponding to 10-100 times the accretion rate to the AGN, indicating that most of the NLR gas mass has been entrained from the galaxy plane. The average kinetic power of the NLR outflows is ~10^-4 times the bolometric luminosity.Comment: 4 pages, 2 figures, to appear in the proceedings of the conference "The Monster's Fiery Breath", eds. Sebastian Heinz and Eric Wilcot

Feeding Versus Feedback in AGNs from Near-Infrared IFU Observations: The Case of Mrk79

We have mapped the gaseous kinematics and the emission-line flux distributions and ratios from the inner ~680pc radius of the Seyfert 1 galaxy Mrk79, using two-dimensional (2D) near-IR J- and Kl-band spectra obtained with the Gemini instrument NIFS at a spatial resolution of ~100pc and velocity resolution of ~40km/s. The molecular hydrogen flux distribution presents two spiral arms extending by ~700pc, one to the north and another to the south of the nucleus, with an excitation indicating heating by X-rays from the central source. The low velocity dispersion (sigma~50km/s) and rotation pattern supports a location of the H2 gas in the disk of the galaxy. Blueshifts observed along the spiral arm in the far side of the galaxy and redshifts in the spiral arm in the near side, suggest that the spiral arms are feeding channels of H2 to the inner 200pc. From channel maps along the H2 l2.1218um emission-line profile we estimate a mass inflow rate of ~4E-3 M_Sun/year, which is one order of magnitude smaller than the mass accretion rate necessary to power the AGN of Mrk79. The emission from the ionized gas (traced by Pabeta and [FeII]l1.2570um emission lines) is correlated with the radio jet and with the narrow-band [OIII] flux distribution. Its kinematics shows both rotation and outflows to the north and south of the nucleus. The ionized gas mass outflow rate through a cross section with radius ~320pc located at a distance of ~455pc from the nucleus is 3.5 MSun/year, which is much larger than the AGN mass accretion rate, indicating that most of the outflowing gas originates in the interstellar medium surrounding the galaxy nucleus, which is pushed away by a nuclear jet.Comment: Accepted by MNRA

Spectral Models for Low-luminosity Active Galactic Nuclei in LINERs: The Role of Advection-dominated Accretion and Jets

We perform an exploratory study of the physical properties of accretion flows and jets in low-luminosity active galactic nuclei (LLAGNs) by modeling the spectral energy distributions (SEDs) of 12 LLAGNs in low-ionization nuclear emission-line regions (LINERs). These SEDs we constructed from high-resolution radio, X-ray and optical/UV observations of the immediate vicinity of the black hole. We adopt a coupled accretion-jet model comprising an inner advection-dominated accretion flow (ADAF) and an outer standard thin disk. We present best-fit models in which either the ADAF or the jet dominate the X-ray emission. Six sources in our sample display an optical-UV excess with respect to ADAF and jet models; this excess can be explained as emission from the truncated disk with transition radii 30-225 Rs in four of them. In almost all sources the optical emission can also be attributed to unresolved, old stellar clusters with masses ~1E7-1E8 Msun. We find evidence for a correlation between the accretion rate and jet power and an anti-correlation between the radio-loudness and the accretion rate. We confirm previous findings that the radio emission is severely underpredicted by ADAF models and explained by the relativistic jet. We find evidence for a nonlinear relation between the X-ray and bolometric luminosities and a slight IR excess in the average model SED compared to that of quasars. We suggest that the hardness of the X-ray spectrum can be used to identify the X-ray emission mechanism and discuss directions for progress in understanding the origin of the X-rays.Comment: Accepted for publication in MNRAS. 27 pages, 22 figures. arXiv admin note: substantial text overlap with arXiv:1112.464