ALBERT

Beschreibung: We present a two-dimensional analysis of the gaseous excitation and kinematics of the inner 2.5 1.7 kpc 2 of the low-ionization nuclear emission-line region (LINER)/Seyfert 1 galaxy Arp 102B, from optical spectra obtained with the Gemini Multi-Object Spectrograph Integral Field Unit on the Gemini North telescope at a spatial resolution of 250 pc. Emission-line flux maps show the same two-armed nuclear spiral we have discovered in previous observations with the Hubble Space Telescope Advanced Camera for Surveys. One arm reaches 1 kpc to the east and the other 500 pc to the west, with an 8.4 GHz Very Large Array bent radio jet correlating with the former. Gas excitation along the arms is low, with line ratios typical of LINERs, and which rule out gas ionization by stars. The gas density is highest (500–900 cm –3 ) at the nucleus and in the northern border of the east arm, at a region where the radio jet seems to be deflected. Centroid velocity maps suggest that most gas is in rotation in an inclined disc with line of nodes along position angle 88°, redshifts to the west and blueshifts to the east, with lower blueshifts correlated with the eastern arm and radio jet. This correlation suggests that the jet is interacting with gas in the disc. This interaction is supported by the gas excitation as a function of distance from the nucleus, which requires the contribution from shocks. Channel maps show blueshifts but also some redshifts at the eastern arm and jet location which can be interpreted as originated in the front and back walls of an outflow pushed by the radio jet, suggesting also that the outflow is launched close to the plane of the sky. Principal Component Analysis applied to our data supports this interpretation. We estimate a mass outflow rate along the east arm of 0.26-0.32 M yr – 1 (depending on the assumed outflow geometry), which is between one and two orders of magnitude higher than the mass accretion rate to the active nucleus, implying that there is mass-loading of the nuclear outflow from circumnuclear gas. The power of this outflow is 0.06–0.3 per cent L bol . We propose a scenario in which gas has been recently captured by Arp 102B in an interaction with Arp 102A, settling in a disc rotating around the nucleus of Arp 102B and triggering its nuclear activity. A nuclear jet is pushing the circumnuclear gas, giving origin to the nuclear arms. A blueshifted emitting gas knot is observed at 300 pc southeast from the nucleus and can be interpreted as another (more compact) outflow, with a possible counterpart to the northwest.

Beschreibung: 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 ] 1.644 μm, H 2 2.122 μm and Br. The [Fe ii ] emission line provides a better coverage of the NLR outflow than the previously used [O iii ] 5007 emission line, extending beyond the area of the bipolar cone observed in Br 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 L Bol . The molecular (H 2 ) gas kinematics is completely distinct from that of [Fe ii ] and Br, 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.

Beschreibung: 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 K l -band spectra obtained with the Gemini Near Infrared Integral Field Spectrograph at a spatial resolution of 60 pc and velocity resolution of 40 km s –1 . Emission-line flux distributions in ionized and molecular gas extend up to 300 pc from the nucleus. Coronal [S ix ] 1.2523 μm line emission is resolved, being extended up to 150 pc from the nucleus. At the highest flux levels, the [Fe ii ] 1.257 μm line emission is most extended to the south-east, where a radio jet has been observed. The emission-line ratios [Fe ii ] 1.2570 μm/Paβ and H 2 2.1218 μm/Br 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 H 2 than for Paβ, indicating that the molecular gas has a colder kinematics and is located in the galaxy plane. There is about 10 3 M of hot H 2 , implying 10 9 M of cold molecular gas. At the location of the radio jet, we observe an increase in the [Fe ii ] velocity dispersion (150 km s –1 ), 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 M  yr –1 , and the power of the outflow 0.08 L bol .

Beschreibung: We have used optical Integral Field Spectroscopy in order to map the star formation history of the inner kiloparsec of the post-starburst quasar (PSQ) J0330–0532 and to map its gas and stellar kinematics as well as the gas excitation. PSQs are hypothesized to represent a stage in the evolution of galaxies in which the star formation has been recently quenched due to the feedback of the nuclear activity, as suggested by the presence of the post-starburst population at the nucleus. We have found that the old stellar population (age ≥ 2.5 Gyr) dominates the flux at 5100 Å in the inner 0.26 kpc, while both the post-starburst (100 Myr ≤ age 〈2.5 Gyr) and starburst (age 〈100 Myr) components dominate the flux in a circumnuclear ring at 0.5 kpc from the nucleus. With our spatially resolved study we have not found any post-starburst stellar population in the inner 0.26 kpc. On the other hand, we do see the signature of AGN feedback in this region, which does not reach the circumnuclear ring where the post-starburst population is observed. We thus do not support the quenching scenario for the PSQ J0330–0532. In addition, we have concluded that the strong signature of the post-starburst population in larger aperture spectra (e.g. from Sloan Digital Sky Survey) is partially due to the combination of the young and old age components. Based on the M BH – star relationship and the stellar kinematics we have estimated a mass for the supermassive black hole of 1.48 ± 0.66 10 7 M .

Beschreibung: We present two-dimensional stellar and gaseous kinematics of the inner 0.8 1.1 kpc 2 of the LINER/Seyfert 1 galaxy NGC 7213, from optical spectra obtained with the Gemini Multi-Object Spectrograph integral field spectrograph on the Gemini South telescope at a spatial resolution of  60 pc. The stellar kinematics shows an average velocity dispersion of 177 km s –1 , circular rotation with a projected velocity amplitude of 50 km s –1 and a kinematic major axis at a position angle of –4° (west of north). From the average velocity dispersion we estimate a black hole mass of M BH  = 8  $_{-6}^{+16}\times$ 10 7 M . The gas kinematics is dominated by non-circular motions, mainly along two spiral arms extending from the nucleus out to 4 arcsec (280 pc) to the NW and SE, that are cospatial with a nuclear dusty spiral seen in a structure map of the nuclear region of the galaxy. The projected gas velocities along the spiral arms show blueshifts in the far side and redshifts in the near side, with values of up to 200 km s –1 . This kinematics can be interpreted as gas inflows towards the nucleus along the spiral arms if the gas is in the plane of the galaxy. We estimate the mass inflow rate using two different methods. The first is based of the observed velocities and geometry of the flow, and gives a mass inflow rate in the ionized gas of 7 10 –2 M yr –1 . In the second method, we calculate the net ionized gas mass flow rate through concentric circles of decreasing radii around the nucleus resulting in mass inflow rates ranging from 0.4 M yr –1 at 300 pc down to 0.2 M yr –1 at 100 pc from the nucleus. These rates are larger than necessary to power the active nucleus.

Beschreibung: We perform an exploratory study of the physical properties of accretion flows and jets in low-luminosity active galactic nuclei (LLAGNs) by modelling 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/ultraviolet (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 disc. We present best-fitting models in which either the ADAF or the jet dominates 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 disc with transition radii 30–225 R S in four of them. In almost all sources the optical emission can also be attributed to unresolved, old stellar clusters with masses ~10 7 –10 8 M . We find evidence for a correlation between the accretion rate and jet power and an anticorrelation 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 non-linear 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.

Beschreibung: We have mapped the gaseous kinematics and the emission-line flux distributions and ratios from the inner 680 pc radius of the Seyfert 1 galaxy Mrk 79, using two-dimensional (2D) near-infrared J - and K l -band spectra obtained with the Gemini instrument Near-Infrared Integral Field Spectrograph at a spatial resolution of 100 pc and velocity resolution of 40 km s –1 . The molecular hydrogen H 2 flux distribution presents two spiral arms extending by 700 pc, 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 ( 50 km s –1 ) and rotation pattern supports a location of the H 2 gas in the disc 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 H 2 to the inner 200 pc. From channel maps along the H 2 2.1218 μm emission-line profile we estimate a mass inflow rate of $\dot{M}_{{\rm H}_2}\approx 4\times 10^{-3}\, {\rm M_{\odot }\,yr^{-1}}$ , which is one order of magnitude smaller than the mass accretion rate necessary to power the active galactic nucleus (AGN) of Mrk 79. The emission from the ionized gas (traced by Paβ and [Fe ii ] 1.2570 μm emission lines) is correlated with the radio jet and with the narrow-band [O iii ] 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 320 pc located at a distance of 455 pc from the nucleus is $\dot{M}_{\rm out}\approx 3.5\, {\rm M_{\odot }\, yr^{-1}}$ , 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.

Beschreibung: We present emission-line flux distributions and ratios for the inner 200 pc of the narrow-line 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 H 2 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 ] 5007 ionization bi-cone. But while the flux distributions in the H i and He ii emission lines are very similar to that observed in [O iii ], 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 M H ii 2.2 x 10 4 M , while the mass of the H 2 emitting gas is only M H 2 29 M . Taking into account the dominant contribution of the cold molecular gas, we obtain an estimate of the total molecular gas mass of M cold 2 x 10 7 M .

Beschreibung: We present two-dimensional gaseous kinematics of the inner 1.1 1.6 kpc 2 of the Seyfert 2 galaxy NGC 2110, from optical spectra (5600–7000 Å) obtained with the Gemini Multi Object Spectrograph integral field spectrograph on the Gemini South telescope at a spatial resolution of 100 pc. Gas emission is observed over the whole field of view, with complex – and frequently double – emission-line profiles. We have identified four components in the emitting gas, according to their velocity dispersion (), which we refer to as: (1) warm gas disc ( = 100–220 km s –1 ); (2) cold gas disc ( = 60–90 km s –1 ); (3) nuclear component ( = 220–600 km s –1 ) and (4) northern cloud ( = 60–80 km s –1 ). Both the cold and warm disc components are dominated by rotation and have similar gas densities, but the cold gas disc has lower velocity dispersions and reaches higher rotation velocities. We attribute the warm gas disc to a thick gas layer which encompasses the cold disc as observed in some edge-on spiral galaxies. After subtraction of a rotation model from the cold disc velocity field, we observe excess blueshifts of 50 km s –1 in the far side of the galaxy (NE) as well as similar excess redshifts in the near side (SW). These residuals can be interpreted as due to nuclear inflow in the cold gas, with an estimated ionized gas mass inflow rate of   2.2  x 10 –2 M yr –1 . We have also subtracted a rotating model from the warm disc velocity field and found excess blueshifts of 100 km s –1 to the SW of the nucleus and excess redshifts of 40 km s –1 to the NE, which we attribute to gas disturbed by an interaction with a nuclear spherical outflow. This nuclear outflow is the origin of the nuclear component observed within the inner 300 pc and it has a mass outflow rate of 0.9 M yr –1 . In a region between 1 and 4 arcsec north of the nucleus, which shows strong X-ray and [O iii ] 5007 Å emission, we find a new low component of ionized gas which we attribute to a high latitude cloud photoionized by the nuclear source. The identification of the four distinct kinematic components has clarified the nature of the apparent asymmetry in the rotation curve of the galaxy pointed out in previous studies: it results from the dominance of different components to the south and north of the nucleus. We conclude that a comprehensive two-dimensional coverage of the kinematics and geometry of the nuclear gas around the active galactic nucleus is necessary to reveal the different processes at play, such as its feeding – via the cold inflowing gas – and the feedback, via the warm gas outflows.