Mass Outflow Rate Research Articles

Magnetohydrodynamic Numerical Simulation of the Outflows Driven by Magnetic Field and Radiation Force from the Corona above a Thin Disk

Abstract A hot corona is suggested to be above the standard thin disk. The anisotropy of hard X-ray emission in radio-quiet active galactic nuclei implies that the corona is not static and probably moves outwards like winds. We perform two-dimensional magnetohydrodynamical simulations to study the outflowing corona driven by magnetic field and radiation force. In our simulations, as the initial state and the boundary condition at the disk surface, the corona temperature is set to 109 K inside a 10 Schwarzschild radius (r s), while the corona temperature is set to 107 K outside 10 r s. We employ a weak poloidal magnetic field as the initial magnetic field. A collimated outflow and a wide-angle ordered outflow are observed in our simulations. The collimated outflow is around the rotational axis and has a bulk velocity of ∼0.03–0.3c (c is speed of light) at 90 r s, while their mass outflow rate is very low. The collimated outflow is a weak jet. The wide-angle ordered outflow is distributed at middle and high latitudes and moves outwards with a velocity of 102–104 km s−1. The outflow velocity depends on the disk luminosity. The gas around the disk surface is turbulent, especially outside of 10 r s. The other properties of outflows are discussed in detail.

The gentle monster PDS 456

We report on the first ALMA observation of the CO(3−2) and rest-frame ∼340 GHz continuum emission in PDS 456, which is the most luminous, radio-quiet QSO in the local Universe (z ≃ 0.18), with a bolometric luminosity LBol ∼ 1047 erg s−1. ALMA angular resolution allowed us to map scales as small as ∼700 pc. The molecular gas reservoir traced by the core of the very bright CO(3−2) emission line is distributed in a compact rotating disk, with a size of ∼1.3 kpc, seen close to face-on (i ∼ 25 deg). Fast CO(3−2) emission in the velocity range v ∈ [ − 1000, 500] km s−1 is also present. Specifically, we detect several blue-shifted clumps out to ∼5 kpc from the nucleus, in addition to a compact (R ≲ 1.2 kpc), broad emission component. These components reveal a galaxy-wide molecular outflow, with a total mass Mmolout ∼ 2.5 × 108 M⊙ (for an αCO = 0.8 M⊙ (K km s−1 pc2)−1) and a mass outflow rate Ṁmol ∼ 290 M⊙ yr−1. The corresponding depletion time is τdep ∼ 8 Myr, shorter than the rate at which the molecular gas is converted into stars, indicating that the detected outflow is potentially able to quench star-formation in the host. The momentum flux of the molecular outflow normalised to the radiative momentum output (i.e. LBol/c) is ≲1, comparable to that of the X-ray ultra-fast outflow (UFO) detected in PDS 456. This is at odds with the expectations for an energy-conserving expansion suggested for most of the large-scale outflows detected in low-luminosity AGNs so far. We suggest three possible scenarios that may explain this observation: (i) in very luminous AGNs such as our target the molecular gas phase is tracing only a fraction of the total outflowing mass; (ii) a small coupling between the shocked gas by the UFO and the host-galaxy interstellar medium (ISM); and (iii) AGN radiation pressure may be playing an important role in driving the outflow.

Quantifying the AGN-driven outflows in ULIRGs (QUADROS) IV: HST/STIS spectroscopy of the sub-kpc warm outflow in F14394+5332

ABSTRACT Considerable uncertainties remain about the nature of warm, AGN-driven outflows and their impact on the evolution of galaxies. This is because the outflows are often unresolved in ground-based observations. As part of a project to study the AGN outflows in some of the most rapidly evolving galaxies in the local Universe, here we present Hubble Space Telescope (HST)/Space Telescope Imaging Spectrograph (STIS) observations of F14394+5332E that resolve the sub-kpc warm outflow for the first time in an ultra-luminous infrared galaxy. The observations reveal a compact, high-ionization outflow region (rmax ∼ 0.9 kpc) set in a more extensive (rmax ∼ 1.4 kpc) halo that is kinematically quiescent and has a lower ionization state. A large line width (600 < FWHM < 1500 km s−1) is measured throughout the outflow region, and the outflowing gas shows a steep velocity gradient with radius, with the magnitude of the blueshifted velocities increasing from ∼500 to 1800 km s−1 from the inner to the outer part of the outflow. We interpret the observations in terms of the local acceleration, and hydrodynamic destruction, of dense clouds as they are swept up in a hot, low-density wind driven by the AGN. We discuss the implications for measuring the mass outflow rates and kinetic powers for the AGN-driven outflows in such objects.

Uncovering QSO-driven outflows and galaxy assembly at cosmic Dawn with ALMA

AbstractI will present evidence of QSO-driven outflows in the early Universe, resulting from the stacking analysis of ALMA observations of the [CII] emission line for a sample of 50 QSOs at z ∼ 5 – 7. The high sensitivity reached by our analysis allowed us to assess that very broad wings are on average present in the [CII] profile, and extend beyond velocities of 1000 km/s in systems with low and high SFR. Such wings are therefore tracing QSO-driven [CII] outflows, with associated mass outflow rates of 100 – 200Mȯ / yr. I will discuss how these outflows relate to those observed in lower-z AGNs and give an estimate of their spatial extent. Furthermore, I will focus on the high-resolution ALMA observation of a hyper luminous QSO at z ∼ 4.5, revealing an exceptional overdensity with multiple companions as close as 2 kpc. These crowded surroundings, and the QSO host galaxy itself, are forming stars at a very high rate (hundreds of Mȯ / yr), suggesting that a significant fraction of the stellar mass assembly at early epochs might have taken place in the companions. I will discuss how the BH and host-galaxy masses are growing in this multi- source system, which likely represents the cradle of what would be a giant galaxy at z = 0.

Outflows in the Disks of Active Galaxies

Abstract Recent advances in observations have provided a wealth of measurements of the expansions of outflows in galactic disks out to large radii in a variety of galactic hosts. To provide an updated baseline for the interpretation of such data, and to assess to what extent the present status of the modeling is consistent with the existing observations, we provide a compact two-dimensional description for the expansion of active galactic nucleus (AGN)-driven shocks in realistic galactic disks with exponential gas density profiles in a disk geometry. We derive solutions for the outflow expansion and the mass outflow rates in different directions with respect to the plane of the disk. These are expressed in terms of the global properties of the host galaxy and of the central AGN to allow for an easy and direct comparison with existing observations in a variety of galactic hosts with measured properties, and out to distances of ∼10 kpc from the center. The results are compared with a state-of-the-art compilation of observed outflows in 19 galaxies with different measured gas and dynamical mass, allowing for a detailed, one-by-one comparison with the model predictions. The agreement we obtain for a wide range of host galaxy gas mass ( ) and AGN bolometric luminosity ( ) provides a quantitative systematic test for the modeling of AGN-driven outflows in galactic disks. We also consider a larger sample of 48 objects in galaxies with no reliable measurements of the gas and dynamical mass. In this case, we perform a comparison of the model predictions for different bins of AGN luminosities assuming different reference values for the gas mass and dynamical mass derived from average scaling relations. Finally, we reconsider the AGN wind scaling laws empirically derived by many authors in light of the results from our updated models. The encouraging, quantitative agreement of the model predictions with a wide set of existing observations constitutes a baseline for the interpretation of forthcoming data, and for a more detailed treatment of AGN feedback in galaxy formation models.

A near-infrared study of the multiphase outflow in the type-2 quasar J1509+0434

ABSTRACT Based on new near-infrared spectroscopic data from the instrument Espectrógrafo Multiobjeto Infra-Rojo (EMIR) on the 10.4 m Gran Telescopio Canarias, we report the presence of an ionized and warm molecular outflow in the luminous type-2 quasar J150904.22+043441.8 (z = 0.1118). The ionized outflow is faster than its molecular counterpart, although the outflow sizes that we derive for them are consistent within the errors (1.34 ± 0.18 and 1.46 ± 0.20 kpc, respectively). We use these radii, the broad emission-line luminosities and in the case of the ionized outflow, the density calculated from the trans-auroral [O ii] and [S ii] lines, to derive mass outflow rates and kinetic coupling efficiencies. While the ionized and warm molecular outflows represent a small fraction of the AGN power (≤0.033 and 0.0001 per cent of Lbol, respectively), the total molecular outflow, whose mass is estimated from an assumed warm-to-cold gas mass ratio of 6 × 10−5, has a kinetic coupling efficiency of ∼1.7 per cent Lbol. Despite the large uncertainty, this molecular outflow represents a significant fraction ofLbol and it could potentially have a significant impact on the host galaxy. In addition, the quasar spectrum reveals bright and patchy narrow Paα emission extending out to 4 arcsec (8 kpc) south-east and north-west from the active nucleus.

Outflows, inflows, and young stars in the inner 200 pc of the Seyfert galaxy NGC 2110

ABSTRACT We present a 2D mapping of stellar population age components, emission-line fluxes, gas excitation, and kinematics within the inner ∼200 pc of the Seyfert 2 galaxy NGC 2110. We used the Gemini North Integral Field Spectrograph (NIFS) in the J and K bands at a spatial resolution of ∼22 pc. The unresolved nuclear continuum is originated in combined contributions of young stellar population (SP; age ≤ 100 Myr), a featureless AGN continuum and hot dust emission. The young-intermediate SP (100 < age ≤ 700 Myr) is distributed in a ring-shaped structure at ≈140 pc from the nucleus, which is roughly coincident with the lowest values of the stellar velocity dispersion. In the inner ≈115 pc the old SP (age > 2 Gyr) is dominant. The [Fe ii] $\lambda \, 1.2570\, \mu$m emission-line flux distribution is correlated with the radio emission and its kinematics comprise two components, one from gas rotating in the galaxy plane and another from gas in outflow within a bicone-oriented along north–south. These outflows seem to originate in the interaction of the radio jet with the ambient gas producing shocks that are the main excitation mechanism of the [Fe ii] emission. We estimate: (1) an ionized gas mass outflow rate of ∼0.5 M⊙ yr−1 at ∼70 pc from the nucleus; and (2) a kinetic power for the outflow of only 0.05 per cent of the AGN bolometric luminosity implying weak feedback effect on the galaxy.

The energetics of starburst-driven outflows at z ∼ 1 from KMOS

We present an analysis of the gas outflow energetics from KMOS observations of 529 main-sequence star-forming galaxies at z 1 using broad, underlying Hα and forbid- den lines of [Nii] and [Sii]. Based on the stacked spectra for a sample with median star- formation rates and stellar masses of SFR=7M⊙ / yr and M⋆ =(1.0±0.1)×1010M⊙ respectively, we derive a typical mass outflow rate of ˙Mwind =1–4M⊙ yr−1 and a mass loading of ˙Mwind / SFR=0.2–0.4. By comparing the kinetic energy in the wind with the energy released by supernovae, we estimate a coupling efficiency between the star formation and wind energetics of ǫ 0.03. The mass loading of the wind does not show a strong trend with star-formation rate over the range 2–20M⊙ yr−1, although we identify a trend with stellar mass such that dM/ dt / SFR/M0.26±0.07 ⋆ . Finally, the line width of the broad Hα increases with disk circular velocity with a sub-linear scal- ing relation FWHMbroad /v0.21±0.05. As a result of this behavior, in the lowest mass galaxies (M⋆ < ∼ 1010M⊙), a significant fraction of the outflowing gas should have suf- ficient velocity to escape the gravitational potential of the halo whilst in the highest mass galaxies (M⋆ > ∼ 1010M⊙) most of the gas will be retained, flowing back on to the galaxy disk at later times.

Spatially Resolved Outflows in a Seyfert Galaxy at z = 2.39

Abstract We present the first spatially resolved analysis of rest-frame optical and UV imaging and spectroscopy for a lensed galaxy at z = 2.39 hosting a Seyfert active galactic nucleus (AGN). Proximity to a natural guide star has enabled observations with high signal-to-noise ratio using Very Large Telescope SINFONI + adaptive optics (AO) of rest-frame optical diagnostic emission lines, which exhibit an underlying broad component with full width at half maximum ∼ 700 km s−1 in both the Balmer and forbidden lines. Measured line ratios place the outflow robustly in the region of the ionization diagnostic diagrams associated with AGNs. This unique opportunity—combining gravitational lensing, AO guiding, redshift, and AGN activity—allows for a magnified view of two main tracers of the physical conditions and structure of the interstellar medium in a star-forming galaxy hosting a weak AGN at Cosmic Noon. By analyzing the spatial extent and morphology of the Lyα and dust-corrected Hα emission, disentangling the effects of star formation and AGN ionization on each tracer, and comparing the AGN-induced mass outflow rate to the host star formation rate, we find that the AGN does not significantly impact the star formation within its host galaxy.

Discovering AGN-driven winds through their infrared emission – II. Mass outflow rate and energetics

The global influence of AGN-driven outflows remains uncertain, due to a lack of large samples with accurately-determined outflow properties. In the second paper of this series, we determine the mass and energetics of ionized outflows is 234 type II AGN, the largest such sample to date, by combining the infrared emission of the dust in the wind (paper I) with the emission line properties. We provide new general expressions for the properties of the outflowing gas, which depend on the ionization state of the gas. We also present a novel method to estimate the electron density in the outflow, based on optical line ratios and on the known location of the wind. The inferred electron densities, $n_{\mathrm{e}} \sim 10^{4.5}\,\mathrm{(cm^{-3})}$, are two orders of magnitude larger than typically found in most other cases of ionized outflows. We argue that the discrepancy is due to the fact that the commonly-used [SII]-based method underestimates the true density by a large factor. As a result, the inferred mass outflow rates and kinetic coupling efficiencies are $\dot{M}_{\mathrm{out}} \sim 10^{-2}\, \mathrm{(M_{\odot}/yr)}$ and $\epsilon = \dot{E}_{\mathrm{kin}}/L_{\mathrm{bol}} \sim 10^{-5}$ respectively, 1--2 orders of magnitude lower than previous estimates. Our analysis suggests the existence of a significant amount of neutral atomic gas at the back of the outflowing ionized gas clouds, with mass that is a factor of a few larger than the observed ionized gas mass. This has significant implications for the estimated mass and energetics of such flows.

Extreme hydrodynamic losses of Earth-like atmospheres in the habitable zones of very active stars

Aims. In this Letter, we calculate for the first time the full transonic hydrodynamic escape of an Earth-like atmosphere. We consider the case of an Earth-mass planet with an atmospheric composition identical to that of the current Earth orbiting at 1 AU around a young and very active solar mass star. Methods. To model the upper atmosphere, we used the Kompot Code, which is a first-principles model that calculates the physical structures of the upper atmospheres of planets, taking into account hydrodynamics and the main chemical and thermal processes taking place in the upper atmosphere of a planet. This model enabled us to calculate the 1D vertical structure of the atmosphere using as input the high-energy spectrum of a young and active Sun. Results. The atmosphere has the form of a transonic hydrodynamic Parker wind, which has an outflow velocity at the upper boundary of our computational domain that exceeds the escape velocity. The outflowing gas is dominated by atomic nitrogen and oxygen and their ion equivalents and has a maximum ionization fraction of 20%. The mass outflow rate is found to be 1.8 × 109 g s−1, which would erode the modern Earth’s atmosphere in less than 0.1 Myr. Conclusions. This extreme mass loss rate suggests that an Earth-like atmosphere cannot form when the planet is orbiting within the habitable zone of a very active star. Instead, such an atmosphere can only form after the activity of the star has decreased to a much lower level. This happened in the early atmosphere of the Earth, which was likely dominated by other gases such as CO2. Since the time it takes for the activity of a star to decay is highly dependent on its mass, this is important for understanding possible formation timescales for planets orbiting low-mass stars.

GASP – XIX. AGN and their outflows at the centre of jellyfish galaxies

The GASP survey, based on MUSE data, is unveiling the properties of the gas in the so-called "jellyfish" galaxies: these are cluster galaxies with spectacular evidence of gas stripping by ram pressure. In a previous paper, we selected the seven GASP galaxies with the most extended tentacles of ionized gas, and based on individual diagnostic diagrams concluded that at least five of them present clear evidence for an Active Galactic Nucleus. Here we present a more detailed analysis of the emission lines properties in these galaxies. Our comparison of several emission line ratios with both AGN and shock models show that photoionization by the AGN is the dominant ionization mechanism. This conclusion is strengthened by the analysis of $\rm H\beta$ luminosities, the presence of nuclear iron coronal lines and extended ($>10$ kpc) emission line regions ionized by the AGN in some of these galaxies. From emission line profiles, we find the presence of outflows in four galaxies, and derive mass outflow rates, timescales and kinetic energy of the outflows.

Kiloparsec Scale Properties of Star Formation Driven Outflows at z ∼ 2.3 in the SINS/zC-SINF AO Survey*

Abstract We investigate the relationship between star formation activity and outflow properties on kiloparsec scales in a sample of 28 star-forming galaxies at z ∼ 2–2.6, using adaptive optics assisted integral field observations from SINFONI on the Very Large Telescope. The narrow and broad components of the Hα emission are used to simultaneously determine the local star formation rate surface density ( ), and the outflow velocity and mass outflow rate , respectively. We find clear evidence for faster outflows with larger mass loading factors at higher . The outflow velocities scale as ∝ 0.34±0.10, which suggests that the outflows may be driven by a combination of mechanical energy released by supernova explosions and stellar winds, as well as radiation pressure acting on dust grains. The majority of the outflowing material does not have sufficient velocity to escape from the galaxy halos, but will likely be re-accreted and contribute to the chemical enrichment of the galaxies. In the highest regions the outflow component contains an average of ∼45% of the Hα flux, while in the lower regions only ∼10% of the Hα flux is associated with outflows. The mass loading factor, η = /SFR, is positively correlated with but is relatively low even at the highest : η ≲ 0.5 × (380 cm−3/n e ). This may be in tension with the η ≳ 1 required by cosmological simulations, unless a significant fraction of the outflowing mass is in other gas phases and has sufficient velocity to escape the galaxy halos.

Mass outflow of the X-ray emission line gas in NGC 4151

AbstractWe have analyzed Chandra/High Energy Transmission Grating spectra of the X-ray emission line gas in the Seyfert galaxy NGC 4151. The zeroth-order spectral images show extended H- and He-like O and Ne, up to a distance r ˜ 200 pc from the nucleus. Using the 1st-order spectra, we measure an average line velocity ˜230 km s–1, suggesting significant outflow of X-ray gas. We generated Cloudy photoionization models to fit the 1st-order spectra; the fit required three distinct emission-line components. To estimate the total mass of ionized gas (M) and the mass outflow rates, we applied the model parameters to fit the zeroth-order emission-line profiles of Ne IX and Ne X. We determined an M ≍ 5.4 × 105Mʘ. Assuming the same kinematic profile as that for the [O III] gas, derived from our analysis of Hubble Space Telescope/Space Telescope Imaging Spectrograph spectra, the peak X-ray mass outflow rate is approximately 1.8 Mʘ yr–1, at r ˜ 150 pc. The total mass and mass outflow rates are similar to those determined using [O III], implying that the X-ray gas is a major outflow component. However, unlike the optical outflows, the X-ray emitting mass outflow rate does not drop off at r &gt; 100pc, which suggests that it may have a greater impact on the host galaxy.

Taking snapshots of the jet-ISM interplay with ALMA

AbstractWe present an update of our ongoing project to characterise the impact of radio jets on the interstellar medium (ISM). This is done by tracing the distribution, kinematics and excitation of the molecular gas at high spatial resolution using ALMA. The radio active galactic nuclei (AGN) studied are in the interesting phase of having a recently born radio jet. In this stage, the plasma jets can have the largest impact on the ISM, as also predicted by state-of-the-art simulations. The two targets we present have quite different ages, allowing us to get snapshots of the effects of radio jets as they grow and evolve. Interestingly, both also host powerful quasar emission, making them ideal for studying the full impact of AGN. The largest mass outflow rate of molecular gas is found in a radio galaxy () hosting a newly born radio jet still in the early phase of emerging from an obscuring cocoon of gas and dust. Although the molecular mass outflow rate is high (few hundred), the outflow is limited to the inner few hundred pc region. In a second object (), the jet is larger (a few kpc) and is in a more advanced evolutionary phase. In this object, the distribution of the molecular gas is reminiscent of what is seen, on larger scales, in cool-core clusters hosting radio galaxies. Interestingly, gas deviating from quiescent kinematics (possibly indicating an outflow) is not very prominent, limited only to the very inner region, and has a low mass outflow rate. Instead, on kpc scales, the radio lobes appear associated with depressions in the distribution of the molecular gas. This suggests that the lobes have broken out from the dense nuclear region. However, the AGN does not appear to be able, at present, to stop the star formation observed in this galaxy. These results support the idea that the effects of the radio source start in the very first phases by producing outflows which, however, tend to be limited to the kpc region. After that, the effects turn into producing large-scale bubbles which could, in the long term, prevent the surrounding gas from cooling. Thus, our results provide a way to characterise the effect of radio jets in different phases of their evolution and in different environments, bridging the studies done for radio galaxies in clusters.

Multi-phase outflows in Mkn 848 observed with SDSS-MaNGA integral field spectroscopy

Aims. The characterisation of galaxy-scale outflows in terms of their multi-phase and multi-scale nature, amount, and effects of flowing material is crucial to place constraints on models of galaxy formation and evolution. This study can proceed only with the detailed investigation of individual targets. Methods. We present a spatially resolved spectroscopic optical data analysis of Mkn 848, a complex system consisting of two merging galaxies at z ∼ 0.04 that are separated by a projected distance of 7.5 kpc. Motivated by the presence of a multi-phase outflow in the north-west system revealed by the SDSS integrated spectrum, we analysed the publicly available MaNGA data, which cover almost the entire merging system, to study the kinematic and physical properties of cool and warm gas in detail. Results. Galaxy-wide outflowing gas in multiple phases is revealed for the first time in the two merging galaxies. We also detect spatially resolved resonant Na ID emission associated with the outflows. The derived outflow energetics (mass rate, and kinetic and momentum power) may be consistent with a scenario in which both winds are accelerated by stellar processes and AGN activity, although we favour an AGN origin given the high outflow velocities and the ionisation conditions observed in the outflow regions. Further deeper multi-wavelength observations are required, however, to better constrain the nature of these multi-phase outflows. Outflow energetics in the North-West system are strongly different between the ionised and atomic gas components, the latter of which is associated with mass outflow rate and kinetic and momentum powers that are one or two dex higher; those associated with the south-east galaxy are instead similar. Conclusions. Strong kiloparsec-scale outflows are revealed in an ongoing merger system, suggesting that feedback can potentially impact the host galaxy even in the early merger phases. The characterisation of the neutral and ionised gas phases has proved to be crucial for a comprehensive study of the outflow phenomena.

Multiwavelength campaign on Mrk 509

Aims. To elucidate the location, physical conditions, mass outflow rate, and kinetic luminosity of the outflow from the active nucleus of the Seyfert 1 galaxy Mrk 509, we used coordinated UV and X-ray spectral observations in 2012 to follow up our lengthier campaign conducted in 2009. Methods. We observed Mrk 509 with the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST) on 2012-09-03 and 2012-10-11 coordinated with X-ray observations using the High Energy Transmission Grating on the Chandra X-ray Observatory. Our far-ultraviolet spectra used grating G140L on COS to cover wavelengths from 920–2000 Å at a resolving power of ∼2000, and gratings G130M and G160M to cover 1160–1750 Å at a resolving power of ∼15, 000. Results. We detect variability in the blueshifted UV absorption lines on timescales spanning 3–12 years. The inferred densities in the absorbing gas are greater than log n cm−3 ∼ 3. For ionization parameters ranging over log U = −1.5 to −0.2, we constrain the distances of the absorbers to be closer than 220 pc to the active nucleus. Conclusions. The impact on the host galaxy appears to be confined to the nuclear region.

HST observations of [O III] emission in nearby QSO2s: Physical properties of the outflows

AbstractWe used Space Telescope Imaging Spectrograph (STIS) long slit medium-resolution G430M and G750M spectra to analyze the extended [O III] λ5007 emission in a sample of twelve QSO2s from Reyes et al. (2008). The purpose of the study was to determine the properties of the mass outflows and their role in AGN feedback. We measured fluxes and velocities as functions of deprojected radial distances. Using photoionization models and ionizing luminosities derived from [O III], we were able to estimate the densities for the emission-line gas. From these results, we derived masses, mass outflow rates, kinetic energies and kinetic luminosity rates as a function of radial distance for each of the targets. Masses are several times 103 - 107 solar masses, which are comparable to values determined from a recent photoionization study of Mrk 34 (Revalski). Additionally, we are studying the possible role of X-ray winds in these QSO2s.

Feedback from ionised gas outflows in the central kpc of nearby active galaxies

AbstractWe use integral-field spectroscopy obtained with the Gemini instrument GMOS-IFU (Gemini Multi-Object Spectrograph Integral Field Unit) to map the gas distribution, excitation and kinematics in the central kpc of 11 nearby active galaxies. We use channel maps to quantify the ionised gas masses, mass outflow rates and powers of the outflows in order to gauge the feedback effect of these outflows on the host galaxies. We compare this method with others previously used to calculate the feedback power of such outflows.

Mapping the inner kpc of the interacting Seyfert galaxy NGC 2992: Stellar populations and gas kinematics

AbstractWe present Gemini Multi-Object Spectrograph Integral Field Unit (GMOS-IFU) observations of the inner 1.1 kpc of the interacting Seyfert galaxy NGC 2992. From full spectral synthesis we found that the stellar population is mainly (up to 80 per cent of the total light) composed by an old (t ≥ 1.4 Gyr) metal-rich (Z ≥ 2.0) populations with a smaller but considerable contribution (up to 30 per cent) from young (t ≤ 100 Myr) metal-poor (Z ≥ 1.0) populations. The gas kinematics presents two main components: one from gas in orbit in the galaxy disk and an outflow with mass outflow rate of ˜2 Mʘ yr–1 and a kinematic power of ˜ 2 × 1040 erg s–1.