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For the first time, the helium abundance relative to hydrogen (He/H), which relied on direct measurements of the electron temperature, has been derived in the narrow line regions (NLRs) from a local sample of Seyfert 2 nuclei. In view of this, optical emission line intensities [3000 < λ(Å)

We study the gas distribution and kinematics of the inner kpc of six moderately luminous (43.43 ≤ log Lbol ≤ 44.83) nearby (0.004 ≤ z ≤ 0.014) Seyfert galaxies observed with the Near-infrared Integral Field Spectrograph (NIFS) in the J (⁠1.25μm) and K (⁠2.2μm) bands. We analyse the most intense emission lines detected on these spectral wavebands: [Fe ii] 1.2570μm and Paβ, which trace the ionized gas in the partially and fully ionized regions, and H2 2.1218μm, which traces the hot (∼2000 K) molecular gas. The dominant kinematic component is rotation in the disc of the galaxies, except for the ionized gas in NGC 5899 that shows only weak signatures of a disc component. We find ionized gas outflow in four galaxies, while signatures of H2 outflows are seen in three galaxies. The ionized gas outflows display velocities of a few hundred km s−1, and their mass outflow rates are in the range 0.005–12.49 M⊙ yr−1. Their kinetic powers correspond to 0.005–0.7 per cent of the active galactic nuclei (AGN) bolometric luminosities. Besides rotation and outflows signatures in some cases, the H2 kinematics also reveals inflows in three galaxies. The inflow velocities are 50–80 km s−1 and the mass inflow rates are in the range 1–9 × 10−4 M⊙ yr−1 for hot molecular gas. These inflows might be only the hot skin of the total inflowing gas, which is expected to be dominated by colder gas. The mass inflow rates are lower than the current accretion rates to the AGN, and the ionized outflows are apparently disturbing the gas in the inner kpc.

In modern models and simulations of galactic evolution, the star formation in massive galaxies is regulated by an ad hoc active galactic nuclei (AGN) feedback process. However, the physics and the extension of such effects on the star formation history of galaxies is matter of vivid debate. In order to shed some light in the AGN effects over the star formation, we analysed the inner 500 × 500 pc of a sample of 14 Seyfert galaxies using GMOS and MUSE integral field spectroscopy. We fitted the continuum spectra in order to derive stellar age, metallicity, velocity, and velocity dispersion maps in each source. After stacking our sample and averaging their properties, we found that the contribution of young SP, as well as that of AGN featureless continuum both peak at the nucleus. The fraction of intermediate-age SPs is smaller in the nucleus if compared to outer regions, and the contribution of old SPs vary very little within our field of view (FoV). We also found no variation of velocity dispersion or metallicity within our FoV. Lastly, we detected an increase in the dust reddening towards the center of the galaxies. These results lead us to conclude that AGN phenomenon is usually related to a recent star formation episode in the circumnuclear region.

The merger remnant NGC 34 is a local luminous infrared galaxy (LIRG) hosting a nuclear starburst and a hard X-ray source associated with a putative, obscured Seyfert 2 nucleus. In this work, we use adaptive optics assisted near-infrared (NIR) integral field unit observations of this galaxy to map the distribution and kinematics of the ionized and molecular gas in its inner 1.2kpc×1.2kpc⁠, with a spatial resolution of 70 pc. The molecular and ionized gas kinematics is consistent with a disc with projected major axis along a mean PA = −9∘.2 ± 0∘.9. Our main findings are that NGC 34 hosts an AGN and that the nuclear starburst is distributed in a circumnuclear star formation ring with inner and outer radii of ≈ 60 and 180 pc, respectively, as revealed by maps of the [FeII]/Paβ and H2/Br γ emission-line ratios, and corroborated by PCA tomography analysis. The spatially resolved NIR diagnostic diagram of NGC 34 also identifies a circumnuclear structure dominated by processes related to the stellar radiation field and a nuclear region where [FeII] and H2 emissions are enhanced relative to the hydrogen recombination lines. We estimate that the nuclear X-ray source can account for the central H2 enhancement and conclude that [FeII] and H2 emissions are due to a combination of photoionization by young stars, excitation by X-rays produced by the AGN and shocks. These emission lines show nuclear, broad, blueshifted components that can be interpreted as nuclear outflows driven by the AGN.

For the first time, neon abundance has been derived in the narrow line region from a sample of Seyfert 2 nuclei. In view of this, we compiled from the literature fluxes of optical and infrared (IR) narrow emission lines for 35 Seyfert 2 nuclei in the local universe (z 0.06). The relative intensities of emission lines were used to derive the ionic and total neon and oxygen abundances through electron temperature estimations (Te-method). For the neon, abundance estimates were obtained by using both Te-method and IR-method. Based on photoionization model results, we found a lower electron temperature [te(Ne iii)] for the gas phase where the Ne2 + is located in comparison with t3 for the O2 + ion. We find that the differences (D) between Ne2 +/H+ ionic abundances calculated from IR-method and Te-method (assuming t3 in the Ne2 +/H+ derivation) are similar to the derivations in star-forming regions (SFs) and they are reduced by a mean factor of ∼3 when te(Ne iii) is considered. We propose a semi-empirical Ionization Correction Factor (ICF) for the neon, based on [Ne II]12.81μm, [Ne III]15.56μm, and oxygen ionic abundance ratios. We find that the average Ne/H abundance for the Seyfert 2s sample is nearly 2 times higher than similar estimate for SFs. Finally, for the very high metallicity regime (i.e. [12 + log(O/H) 8.80]) an increase in Ne/O with O/H is found, which likely indicates secondary stellar production for the neon.

The near-infrared spectra of active galactic nuclei (AGN) present emission lines of different atomic and molecular species. The mechanisms involved in the origin of these emission lines in AGN are still not fully understood. We use J- and K-band integral field spectra of six luminous (43.1 < logLbol/(erg s−1) < 44.4) Seyfert galaxies (NGC 788, Mrk 607, NGC 3227, NGC 3516, NGC 5506, and NGC 5899) in the local Universe (0.0039

We investigate the ionized gas excitation and kinematics in the inner 4.3 × 6.2 kpc2 of the merger radio galaxy 4C+29.30. Using optical integral field spectroscopy with the Gemini North Telescope, we present flux distributions, line-ratio maps, peak velocities and velocity dispersion maps as well as channel maps with a spatial resolution of ≈955 pc. We observe high blueshifts of up to ∼−650 km s−1 in a region ∼1 arcsec south of the nucleus (the southern knot – SK), which also presents high velocity dispersions (∼250 km s−1), which we attribute to an outflow. A possible redshifted counterpart is observed north from the nucleus (the northern knot – NK). We propose that these regions correspond to a bipolar outflow possibly due to the interaction of the radio jet with the ambient gas. We estimate a total ionized gas mass outflow rate of M˙ out = 25.4+11.5 −7.5 M yr−1with a kinetic power of E˙ = 8.1+10.7 −4.0 × 1042 erg s−1, which represents 5.8+7.6 −2.9 per cent of the active galactic nucleus (AGN) bolometric luminosity. These values are higher than usually observed in nearby active galaxies with the same bolometric luminosities and could imply a significant impact of the outflows in the evolution of the host galaxy. The excitation is higher in the NK – that correlates with extended X-ray emission, indicating the presence of hotter gas – than in the SK, supporting a scenario in which an obscuring dust lane is blocking part of the AGN radiation to reach the southern region of the galaxy.

As part of a high-resolution observational study of feeding and feedback processes occurring in the vicinity of the active galactic nucleus in 40 galaxies, we observed the inner 3′′.5 × 5 arcsec of the nearby spiral and Seyfert 2 galaxy UGC 2024 with the integral field unit of the Gemini-South Telescope. The observations enabled a study of the stellar and gas kinematics in this region at a spatial resolution of 0′′.5 (218 pc), and a spectral resolution of 36 km s−1 over the wavelength range 4100–7300 Å. For the strongest emission-lines (H β, [OIII] λ5007 Å, H α, [NII] λ6584 Å, and [SII] λλ6717,6731 Å) we derived maps of the flux, radial velocity, and velocity dispersion. The flux distribution and kinematics of the [OIII] emission line are roughly symmetric around the nucleus: the radial velocity is close to systemic over the full field of view. The kinematics of the other strong emission lines trace both this systemic velocity component, and ordered rotation (with kinematic centre 0′′.2 north-west of the nucleus). The stellar continuum morphology and kinematics are, however, asymmetrical around the nucleus. We interpret these unusual kinematics as the superposition of a component of gas rotating in the galaxy disc plus a ‘halo’ component of highly ionized gas. This halo either traces a quasi-spherical fountain with average radial velocity 200 km s−1, in which case the total nuclear outflow mass and momentum are 2 × 105 M⊙ and 4 × 107 M⊙ km s−1, respectively, or a dispersion supported halo created by a past nuclear starburst

We present two-dimensional ionized gas and stellar kinematics in the inner 1.4 × 1.9 kpc2 of the Seyfert 2 galaxy ESO 153-G20 obtained with the Gemini-South/Gemini multi-object spectrograph integral field unit (GMOS-IFU) at a spatial resolution of ~250 pc and spectral resolution of 36 km s−1. Strong [O iii], Hα, [N ii] and [S ii] emission lines are detected over the entire field of view. The stellar kinematics trace circular rotation with a projected velocity amplitude of ±96 km s−1, a kinematic major axis in position angle of 11°, and an average velocity dispersion of 123 km s−1. To analyse the gas kinematics, we used aperture spectra, position–velocity diagrams and single/double Gaussian fits to the emission lines. All lines show two clear kinematic components: a rotating component that follows the stellar kinematics, and a larger-dispersion component, close to the systemic velocity (from which most of the [O iii] emission comes), mainly detected to the south-west. We interpret this second component as gas outflowing at ~400 km s−1 in a compact (300 pc) ionization cone with a half-opening angle ≤40°. The counter-cone is probably obscured behind a dust lane. We estimate a mass outflow rate of 1.1 M⊙ yr−1, 200 times larger than the estimated accretion rate on to the supermassive black hole, and a kinetic to radiative power ratio of 1.7 × 10−3. Bar-induced perturbations probably explain the remaining disturbances observed in the velocity field of the rotating gas component.

We have used the Gemini Near-Infrared Integral Field Spectrograph in the J and K bands to map the distribution, excitation, and kinematics of the ionized H ii and warm molecular gas H2, in the inner few 100 pc of six nearby active galaxies: NGC 788, Mrk 607, NGC 3227, NGC 3516, NGC 5506, NGC 5899. For most galaxies, this is the first time that such maps have been obtained. The ionized and H2 gas show distinct kinematics: while the H2 gas is mostly rotating in the galaxy plane with low velocity dispersion (σ), the ionized gas usually shows signatures of outflows associated with higher σ values, most clearly seen in the [Fe ii] emission line. These two gas species also present distinct flux distributions: the H2 is more uniformly spread over the whole galaxy plane, while the ionized gas is more concentrated around the nucleus and/or collimated along the ionization axis of its active galactic nucleus (AGN), presenting a steeper gradient in the average surface mass density profile than the H2 gas. The total H ii masses cover the range 2×105--2×107 M⊙, with surface mass densities in the range 3–150 M⊙ pc−2, while for the warm H2 the values are 103–4 times lower. We estimate that the available gas reservoir is at least ≈ 100 times more massive than needed to power the AGN. If this gas forms new stars the star formation rates, obtained from the Kennicutt–Schmidt scaling relation, are in the range 1–260 × 10−3 M⊙ yr−1. But the gas will also – at least in part – be ejected as the observed outflows

Context. Tracing nuclear inflows and outflows in active galactic nuclei (AGNs), determining the mass of gas involved in them, and their impact on the host galaxy and nuclear black hole requires 3D imaging studies of both the ionized and molecular gas. Aims. We map the distribution and kinematics of molecular and ionized gas in a sample of active galaxies to quantify the nuclear inflows and outflows. Here, we analyze the nuclear kinematics of NGC 1566 via ALMA observations of the CO J:2-1 emission at 24 pc spatial and ∼2.6 km s−1 spectral resolution, and Gemini-GMOS/IFU observations of ionized gas emission lines and stellar absorption lines at similar spatial resolution, and 123 km s−1 of intrinsic spectral resolution. Methods. The morphology and kinematics of stellar, molecular (CO), and ionized ([N II]) emission lines are compared to the expectations from rotation, outflows, and streaming inflows. Results. While both ionized and molecular gas show rotation signatures, there are significant non-circular motions in the innermost 200 pc and along spiral arms in the central kpc (CO). The nucleus shows a double-peaked CO profile (full width at zero intensity of 200 km s−1), and prominent (∼80 km s−1) blue- and redshifted lobes are found along the minor axis in the inner arcseconds. Perturbations by the large-scale bar can qualitatively explain all features in the observed velocity field. We thus favor the presence of a molecular outflow in the disk with true velocities of ∼180 km s−1 in the nucleus and decelerating to 0 by ∼72 pc. The implied molecular outflow rate is 5.6 M⊙ yr−1, with this gas accumulating in the nuclear 2″ arms. The ionized gas kinematics support an interpretation of a similar but more spherical outflow in the inner 100 pc, with no signs of deceleration. There is some evidence of streaming inflows of ∼50 km s−1 along specific spiral arms, and the estimated molecular mass inflow rate, ∼0.1 M⊙ yr−1, is significantly higher than the SMBH accretion rate (ṁ = 4.8 × 10−5 M⊙ yr−1).

We present and characterize a sample of 20 nearby Seyfert galaxies selected for having BAT 14–195 keV luminosities LX ≥ 1041.5 erg s−1, redshift z ≤ 0.015, being accessible for observations with the Gemini Near-Infrared Field Spectrograph (NIFS) and showing extended [O III]λ5007 emission. Our goal is to study Active Galactic Nucleus (AGN) feeding and feedback processes from near-infrared integral-field spectra, which include both ionized (H II) and hot molecular (H2) emission. This sample is complemented by other nine Seyfert galaxies previously observed with NIFS.We show that the host galaxy properties (absolute magnitudes MB, MH, central stellar velocity dispersion and axial ratio) show a similar distribution to those of the 69 BAT AGN. For the 20 galaxies already observed, we present surface mass density ( ) profiles for HII and H2 in their inner ∼500 pc, showing that HII emission presents a steeper radial gradient thanH2. This can be attributed to the different excitationmechanisms: ionization by AGN radiation for HII and heating by X-rays for H2. The mean surface mass densities are in the range (0.2 ≤ HII ≤ 35.9)M pc−2, and (0.2 ≤ H2 ≤ 13.9)× 10−3M pc−2, while the ratios between the HII and H2 masses range between ∼200 and 8000. The sample presented here will be used in future papers to map AGN gas excitation and kinematics, providing a census of the mass inflow and outflow rates and power as well as their relation with the AGN luminosity.

We present optical integral field spectroscopy of the circum-nuclear gas of the Seyfert 2 galaxy NGC 1386. The data cover the central 7″ × 9″ (530 × 680 pc) at a spatial resolution of 0″. 9 (68 pc), and the spectral range 5700–7000 Å at a resolution of 66 km s−1. The line emission is dominated by a bright central component, with two lobes extending ≈3″ north and south of the nucleus. We identify three main kinematic components. The first has low velocity dispersion ( ¯ σ ≈ 90 km s−1), extends over the whole field of view, and has a velocity field consistent with gas rotating in the galaxy disk. We interpret the lobes as resulting from photoionization of disk gas in regions where the active galactic nucleus radiation cones intercept the disk. The second has higher velocity dispersion ( ¯ σ ≈ 200 km s−1) and is observed in the inner 150 pc around the continuum peak. This component is double peaked, with redshifted and blueshifted components separated by ≈500 km s−1. Together with previous Hubble Space Telescope imaging, these features suggest the presence of a bipolar outflow for which we estimate a mass outflow rate of M˙ ≳ 0.1 M⊙ yr−1. The third component is revealed by velocity residuals associated with enhanced velocity dispersion and suggests that outflow and/or rotation is occurring approximately in the equatorial plane of the torus. A second system of velocity residuals may indicate the presence of streaming motions along dusty spirals in the disk.

We have mapped the emission-line flux distributions and ratios as well as the gaseous kinematics of the inner 450 pc radius of the type 1 Seyfert galaxy Mrk 766 using integral field near-infrared J- and Kl-band spectra obtained with the Gemini Near Infrared Integral Field Spectrograph at a spatial resolution of 60 pc and velocity resolution of 40 kms-ˡ. Emission-line flux distributions in ionized and molecular gas extend up to≈300 pc from the nucleus. Coronal [S IX] λ1.2523 μm line emission is resolved, being extended up to 150 pc from the nucleus. At the highest flux levels, the [Fe II] λ1.257 μm line emission is most extended to the south-east, where a radio jet has been observed. The emission-line ratios [Fe II] λ1.2570 μm/Paβ and H2λ2.1218 μm/Brγ show a mixture of Starburst and Seyfert excitation; the Seyfert excitation dominates at the nucleus, to the north-west and in an arc-shaped region between 0.2 and 0.6 arcsec to the south-east at the location of the radio jet. A contribution from shocks at this location is supported by enhanced [Fe II]/[P II] line ratios and increased [Fe II] velocity dispersion. The gas velocity field is dominated by rotation that is more compact for H2 than for Paβ, indicating that the molecular gas has a colder kinematics and is located in the galaxy plane. There is about 103 Mʘ of hot H2, implying ≈109 Mʘ of cold molecular gas. At the location of the radio jet, we observe an increase in the [Fe II] velocity dispersion (150 km s-ˡ), as well as both blueshift and redshifts in the channel maps, supporting the presence of an outflow there. The ionized gas mass outflow rate is estimated to be ≈10 Mʘ yr-ˡ, and the power of the outflow ≈0.08 Lbol.

We present emission-line flux distributions and ratios for the inner ≈200 pc of the narrowline region (NLR) of the Seyfert 2 galaxy NGC 1068, using observations obtained with the Gemini Near-infrared Integral Field Spectrograph (NIFS) in the J, H and K bands at a spatial resolution of ≈10 pc and spectral resolution of ≈5300. The molecular gas emission – traced by the K-band H2 emission lines – outlines an off-centred circumnuclear ring with a radius of ≈100 pc showing thermal excitation. The ionized gas emission lines show flux distributions mostly outlining the previously known [O III] λ5007 ionization bi-cone. But while the flux distributions in the HI and He II emission lines are very similar to that observed in [OIII], the flux distribution in the [Fe II] emission lines is more extended and broader than a cone close to the nucleus, showing a ‘double bowl’ or ‘hourglass’ structure. This difference is attributed to the fact that the [Fe II] emission, besides coming from the fully ionized region, comes also from the more extended partially ionized regions, in gas excited mainly by X-rays from the active galactic nucleus. A contribution to the [Fe II] emission from shocks along the bi-cone axis to north-east and south-west of the nucleus is also supported by the enhancement of the [Fe II](1.2570 μm)/[P II](1.1885 μm) and [Fe II](1.2570 μm)/Paβ emission-line ratios at these locations and is attributed to the interaction of the radio jet with the NLR. The mass of ionized gas in the inner 200 pc of NGC 1068 is MHII ≈ 2.2 × 10⁴ Mʘ, while the mass of the H2 emitting gas is only MH₂ ≈ 29 Mʘ. Taking into account the dominant contribution of the cold molecular gas, we obtain an estimate of the total molecular gas mass of Mcold ≈ 2× 10⁷ Mʘ.

We map the kinematics of the inner (200 pc) narrow-line region (NLR) of the Seyfert 2 galaxy NGC 1068 using the instrument Near-infrared Integral Field Spectrograph and adaptive optics at the Gemini North telescope. Channel maps and position–velocity diagrams are presented at a spatial resolution of ∼= 8 pc and spectral resolution ∼5300 in the emission lines [Fe II] λ1.644 μm, H2 λ2.122 μm and Brγ. The [Fe II] emission line provides a better coverage of the NLR outflow than the previously used [O III] λ5007 emission line, extending beyond the area of the bipolar cone observed in Brγ and [O III]. This is mainly due to the contribution of the redshifted channels to the north-east of the nucleus, supporting its origin in a partial ionized zone with additional contribution from shocks of the outflowing gas with the galactic disc. We modelled the kinematics and geometry of the [Fe II] emitting gas finding good agreement with the data for outflow models with conical and lemniscate (or hourglass) geometry.We calculate a mass outflow rate of 1.9+2 −1 M yr−1 but a power for the outflow of only 0.08 per cent LBol. The molecular (H2) gas kinematics is completely distinct from that of [Fe II] and Brγ , showing radial expansion in an off-centred ∼100 pc radius ring in the galaxy plane. The expansion velocity decelerates from ≈200 km s−1 in the inner border of the ring to approximately zero at the outer border where our previous studies found a 10 Myr stellar population.

We present a revised measurement of themass of the central black hole (MBH ) in the Seyfert 1 galaxyNGC4151. The new stellar dynamical mass measurement is derived by applying an axisymmetric orbit-superposition code to nearinfrared integral field data obtained using adaptive optics with the Gemini Near-infrared Integral Field Spectrograph (NIFS).When our models attempt to fit both the NIFS kinematics and additional low spatial resolution kinematics, our results depend sensitively on how χ2 is computed—probably a consequence of complex bar kinematics that manifest immediately outside the nuclear region. The most robust results are obtained when only the high spatial resolution kinematic constraints in the nuclear region are included in the fit. Our best estimates for the black holemass and H-band mass-to-light ratio are MBH ∼ 3.76±1.15 × 107 M (1σ error) and ϒH ∼ 0.34±0.03 M /L (3σ error), respectively (the quoted errors reflect themodel uncertainties). Our black holemassmeasurement is consistent with estimates from both reverberation mapping (3.57+0.45 −0.37 × 107 M ) and gas kinematics (3.0+0.75 −2.2 × 107 M ; 1σ errors), and our best-fit mass-to-light ratio is consistent with the photometric estimate of ϒH = 0.4 ± 0.2 M /L . The NIFS kinematics give a central bulge velocity dispersion σc = 116 ± 3 kms−1, bringing this object slightly closer to the MBH–σ relation for quiescent galaxies. Although NGC 4151 is one of only a few Seyfert 1 galaxies in which it is possible to obtain a direct dynamical black hole mass measurement—and thus, an independent calibration of the reverberation mapping mass scale—the complex bar kinematics makes it less than ideally suited for this purpose.

We use near-infrared (near-IR) spectroscopic data from the inner few hundred parsecs of a sample of 47 active galaxies to investigate possible correlations between the stellar velocity dispersion (σ ), obtained from the fit of the K-band CO stellar absorption bands, and the gas velocity dispersion (σ), obtained from the fit of the emission-line profiles of [S III] λ0.953 μm, [Fe II] λ1.257 μm, [Fe II] λ1.644 μm and H2 λ2.122 μm. While no correlations with σ were found for H2 and [S III], a good correlation was found for the two [Fe II] emission lines, expressed by the linear fit σ = 95.4 ± 16.1 + (0.25 ± 0.08) × σ[Fe II]. Excluding barred objects from the sample, a better correlation is found between σ and σ[Fe II], with a correlation coefficient of R = 0.80 and fitted by the following relation: σ = 57.9 ± 23.5 + (0.42 ± 0.10) × σ[Fe II]. This correlation can be used to estimate σ in cases where it cannot be directly measured and the [Fe II] emission lines are present in the spectra, allowing us to obtain the mass of the supermassive black hole (SMBH) from the M•–σ relation. The scatter from a one-to-one relationship between σ and its value derived from σ[Fe II] using the equation above for our sample is 0.07 dex, which is smaller than that obtained in previous studies which use σ[O III] in the optical as a proxy for σ . The use of σ[Fe II] in the near-IR instead of σ[O III] in the optical is a valuable option for cases in which optical spectra are not available or are obscured, as in the case of many active galactic nuclei. The comparison between the SMBH masses obtained using the M•–σ relation in which σ was directly measured with those derived from σ[Fe II] reveals only a small average difference of ΔlogM• = 0.02 with a scatter of 0.32 dex for the complete sample and ΔlogM• = 0.00 with a scatter of 0.28 dex for a subsample excluding barred galaxies.

We report the first two-dimensional mapping of the stellar population and non-stellar continua within the inner 180 pc (radius) of NGC 1068 at a spatial resolution of 8 pc, using integral field spectroscopy in the near-infrared. We have applied the technique of spectral synthesis to data obtained with the instrument NIFS and the adaptive optics module ALTAIR at the Gemini North Telescope. Two episodes of recent star formation are found to dominate the stellar population contribution: the first occurred 300 Myr ago, extending over most of the nuclear region; the second occurred just 30 Myr ago, in a ring-like structure at ≈100 pc from the nucleus, where it is coincident with an expanding ring of H2 emission. Inside the ring, where a decrease in the stellar velocity dispersion is observed, the stellar population is dominated by the 300 Myr age component. In the inner 35 pc, the oldest age component (age ≥ 2 Gyr) dominates the mass, while the flux is dominated by blackbody components with temperatures in the range 700 K ≤ T ≤ 800 K which we attribute to the dusty torus. We also find some contribution from blackbody and power-law components beyond the nucleus which we attribute to dust emission and scattered light.

We have used the Gemini Near-infrared Integral Field Spectrograph (NIFS) to map the gas kinematics of the inner ~200 × 500 pc 2 of the Seyfert galaxy NGC4151 in the Z, J, H and K bands at a resolving power of ≥5000 and spatial resolution of ~8 pc. The ionized gas emission is most extended along the known ionization bi-cone at position angle PA = 60◦–240◦, but is observed also along its equatorial plane. This indicates that the active galactic nucleus (AGN) ionizes gas beyond the borders of the bi-cone, within a sphere with ≈1 arcsec radius around the nucleus. The ionized gas has three kinematic components: (1) one observed at the systemic velocity and interpreted as originating in the galactic disc; (2) one outflowing along the bicone, with line-of-sight velocities between −600 and 600 km s-ˡ and strongest emission at ±(100–300) km s-ˡ; and (3) another component due to the interaction of the radio jet with ambient gas. The radio jet (at PA = 75◦–255◦) is not aligned with the narrow-line region (NLR) and produces flux enhancements mostly observed at the systemic velocity, suggesting that the jet is launched close to the plane of the galaxy (approximately plane of the sky). The mass outflow rate, estimated to be ≈1Mʘ yr-ˡ along each cone, exceeds the inferred black hole accretion rate by a factor of ~100. This can be understood if the NLR is formed mostly by entrained gas from the circumnuclear interstellar medium by an outflow probably originating in the accretion disc. This flow represents feedback from the AGN, estimated to release a kinetic power of ˙E ≈ 2.4×10 41 erg s-ˡ,which is only ~0.3 per cent of the bolometric luminosity of the AGN. There is no evidence in our data for the gradual acceleration followed by gradual deceleration proposed by previous modelling of the [O III] emitting gas. Our data allow the possibility that the NLR clouds are accelerated close to the nucleus (within 0.1 arcsec, which corresponds to ≈7 pc at the galaxy) after which the flow moves at essentially constant velocity (≈600 km s-ˡ), being consistent with near-infrared emission arising predominantly from the interaction of the outflow with gas in the galactic disc. The molecular gas exhibits distinct kinematics relative to the ionized gas. Its emission arises in extended regions approximately perpendicular to the axis of the bi-cone and along the axis of the galaxy’s stellar bar, avoiding the innermost ionized regions. It does not show an outflowing component, being observed only at velocities very close to systemic, and is thus consistent with an origin in the galactic plane. This hot molecular gas may only be the tracer of a larger reservoir of colder gas which represents the AGN feeding.

We have used the Gemini Near-infrared Integral Field Spectrograph (NIFS) to map the emission-line intensity distributions and ratios in the narrow-line region (NLR) of the Seyfert galaxy NGC4151 in the Z, J, H and K bands at a resolving power ≥5000, covering the inner ≈200 × 300 pc of the galaxy at a spatial resolution of ≈8 pc. We present intensity distributions in 14 emission lines, which show three distinct behaviours. (1) Most of the ionized gas intensity distributions are extended to ≈100 pc from the nucleus along the region covered by the known biconical outflow (position angle, PA = 60/240◦, NE–SW), consistent with an origin in the outflow; while the recombination lines show intensity profiles which decrease with distance r from the nucleus as I ∝ r-ˡ, most of the forbidden lines present a flat intensity profile (I ∝ rº) or even increasing with distance from the nucleus towards the border of the NLR. (2) The H2 emission lines show completely distinct intensity distributions, which avoid the region of the bicone, extending from ≈10 to ≈60 pc from the nucleus approximately along the large-scale bar, almost perpendicular to the bicone axis. This morphology supports an origin for the H2-emitting gas in the galaxy plane. (3) The coronal lines show a steep intensity profile, described by I ∝ r-²; the emission is clearly resolved only in the case of [Si VII], consistent with an origin in the inner NLR. Using the line-ratio maps [Fe II] 1.644/1.257 and Pa β/Br γ , we obtain an average reddening of E(B − V) ≈ 0.5 along the NLR and E(B − V) ≥ 1 at the nucleus. Our line-ratio map [Fe II] 1.257 μm/[P II] 1.189 μm of the NLR of NGC4151 is the first such map of an extragalactic source. Together with the [Fe II]/Paβ map, these line ratios correlate with the radio intensity distribution, mapping the effects of shocks produced by the radio jet on the NLR. These shocks probably release the Fe locked in grains and produce an enhancement of the [Fe II] emission at ≈1 arcsec from the nucleus. At these regions, we obtain electron densities Ne ≈ 4000 cm-³ and temperatures Te ≈ 15 000K for the [Fe II]-emitting gas. For the H2-emitting gas, we obtain much lower temperatures of Texc ≈ 2100K and conclude that the gas is in thermal equilibrium. The heating necessary to excite the molecule may be due to X-rays escaping perpendicular to the cone (through the nuclear torus, if there is one) or to shocks probably produced by the accretion flow previously observed along the large-scale bar. The distinct intensity distributions and physical properties of the ionized and molecular gas, as well as their locations, the former along the outflowing cone, and the latter in the galaxy plane surrounding the nucleus, suggest that the H2-emitting gas traces the active galactic nuclei feeding, while the ionized gas traces its feedback.

We have used a near-infrared (near-IR) nuclear spectrum (covering the Z, J, H, and K bands) of the nucleus of NGC 4151 obtained with the Gemini Near-Infrared Integral Field Spectrograph (NIFS) and adaptive optics, to isolate and constrain the properties of a near-IR unresolved nuclear source whose spectral signature is clearly present in our data. The near-IR spectrumwas combined with an optical spectrum obtained with the Space Telescope Imaging Spectrograph which was used to constrain the contribution of a power-law component. After subtraction of the power-law component, the near-IR continuum is well fitted by a blackbody function, with T = 1285 ± 50 K, which dominates the nuclear spectrum—within an aperture of radius 0".3—in the near-IR. We attribute the blackbody component to emission by a dusty structure, with hot dust mass MHD = (6.9 ± 1.5) × 10−4 Mʘ , not resolved by our observations, which provide only an upper limit for its distance from the nucleus of 4 pc. If the reddening derived for the narrow-line region also applies to the near-IR source, we obtain a temperature T = 1360±50 K and a mass MHD = (3.1±0.7)×10−4 Mʘ for the hot dust. This structure may be the inner wall of the dusty torus postulated by the unified model or the inner part of a dusty wind originating in the accretion disk.

We report the discovery of gas streaming motions along nuclear spiral arms toward the LINER nucleus of the galaxyNGC 6951. The observations, obtained using theGMOS integral field spectrograph on the Gemini North telescope, yieldedmaps of the flux distributions and gas kinematics in the Hα, [NII] λ6584, and [S II] λλ6717, 6731 emission lines of the inner 7"; 15" of the galaxy. This region includes a circumnuclear star-forming ring with a radius of ~500 pc, a nuclear spiral inside the ring, and the LINER nucleus. The kinematics of the ionized gas is dominated by rotation, but subtraction of a kinematic model of a rotating exponential disk reveals deviations from circular rotation within the nuclear ring that can be attributed to (1) streaming motions along the nuclear spiral arms and (2) a bipolar outflow that seems to be associated with a nuclear jet. On the basis of the observed streaming velocities and geometry of the spiral arms, we estimate a mass inflow rate of ionized gas of ≈3 x 10 4 Mʘ yr-ˡ, which is on the order of the accretion rate necessary to power the LINER nucleus of NGC 6951. Similar streaming motions toward the nucleus of another galaxy with a LINER nucleus, NGC 1097, have been reported by our group in a previous paper. Taken together, these results support a scenario in which nuclear spirals are channels through which matter is transferred from galactic scales to the nuclear region to feed the supermassive black hole.