arXiv subjects

C. Ramos Almeida

Publications and source records attributed to C. Ramos Almeida.

At least 55 records · Page 3Linked to original sources

arXiv2022

Low-power jet-ISM interaction in NGC 7319 revealed by JWST/MIRI MRS

We present JWST/MIRI MRS spectroscopy of NGC7319, the largest galaxy in the Stephan's Quintet, observed as part of the Early Release Observations (ERO). NGC7319 hosts a type 2 active galactic nucleus (AGN) and a low-power radio jet (L_1.4GHz=3.3x10^22 W Hz^-1) with two asymmetric radio hotspots at 430 pc (N2) and 1.5 kpc (S2) projected distances from the unresolved radio core. The MRS data suggest that the molecular material in the disk of the galaxy decelerates the jet and causes this length asymmetry. We find enhanced emission from warm and hot H_2 (T_w=330+-40 K, T_h=900+-60 K) and ionized gas at the intersection between the jet axis and dust lanes in the disk. This emission is coincident with the radio hotspot N2, the hotspot closer to the core, suggesting that the jet-interstellar medium (ISM) interaction decelerates the jet. Conversely, the mid-infrared emission at the more distant hotspot is fainter, more highly ionized, and with lower H_2 excitation, suggesting a more diffuse atomic environment where the jet can progress to farther distances. At the N2 radio hotspot, the ionized gas mass (M_ion=(2.4-12)x10^5 Msun) is comparable to that of the warm H_2, but the former is more turbulent (sigma_ion~300 vs. sigma_H2~150 km/s), so the mechanical energy of the ionized gas is ~1.3-10 times higher. From these estimates, we find that only <1% of the jet energy remains as mechanical energy in these two ISM phases at N2. We also find extended (r>0.3-1.5 kpc) high-ionization emission ([MgV], [NeVI], and [NeV]) close to the radio hotspots. This initial analysis of NGC7319 shows the potential of MIRI/MRS to investigate the AGN feedback mechanisms due to radio jets and their radiation field in the, often heavily dust-enshrouded, central regions of galaxies. Understanding these mechanisms is an essential ingredient in the development of cosmological simulations of galaxy evolution.

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arXiv2022

Warm molecular and ionized gas kinematics in the Type-2 quasar J0945+1737

We analyze Near-Infrared Integral Field Spectrograph (NIFS) observations of the type-2 quasar (QSO2) SDSS J094521.33+173753.2 to investigate its warm molecular and ionized gas kinematics. This QSO2 has a bolometric luminosity of 10$^{45.7}$ erg s$^{-1}$ and a redshift of z = 0.128. The K-band spectra provided by NIFS cover a range of 1.99-2.40 $μ$m where low-ionization (Pa$α$ and Br$δ$), high ionization ([S XI]$λ$1.920 $μ$m and [Si~VI]$λ$1.963 $μ$m) and warm molecular lines (from H$_2$ 1-0S(5) to 1-0S(1)) are detected, allowing us to study the multi-phase gas kinematics. Our analysis reveals gas in ordinary rotation in all the emission lines detected and also outflowing gas in the case of the low- and high-ionization emission lines. In the case of the nuclear spectrum, which corresponds to a circular aperture of 0.3\arcsec~(686 pc) in diameter, the warm molecular lines can be characterized using a single Gaussian component of full width at half maximum (FWHM)= 350-400 km s$^{-1}$, while Pa$α$, Br$δ$, and [Si~VI] are best fitted with two blue-shifted Gaussian components of FWHM$\sim$800 and 1700 km s$^{-1}$, in addition to a narrow component of $\sim$300 km s$^{-1}$. We interpret the blue-shifted broad components as outflowing gas, which reaches the highest velocities, of up to $-$840 km s$^{-1}$, in the south-east direction (PA$\sim$125$^{\circ}$), extending up to a distance of $\sim$3.4 kpc from the nucleus. The ionized outflow has a maximum mass outflow rate of $\dot{\text{M}}_{\text{out, max}}$=42-51 M$_\odot$ yr$^{-1}$, and its kinetic power represents 0.1$\%$ of the quasar bolometric luminosity.

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arXiv2022

Testing the role of AGN on the star formation and metal enrichment of "twin galaxies"

We explore the effect of AGN activity on the star formation history of galaxies by analysing the stellar population properties of ten pairs of nearby twin galaxies -- selected as being visually similar except for the presence of an AGN. The selection of such twin samples represents a method to study AGN feedback, as recently proposed by del Moral Castro et al. We use integral field unit (IFU) data from CALIFA, stacked within three fixed apertures. AGN galaxies in a twin pair suggest more evolved stellar populations than their non-AGN counterpart 90% of the time, regardless of aperture size. A comparison with a large sample from SDSS confirms that most twins are representative of the general population, but in each twin the differences between twin members is significant. A set of targeted line strengths reveal the AGN member of a twin pair is older and more metal rich than the non-AGN galaxy, suggesting AGN galaxies in our sample may either have an earlier formation time or follow a different star formation and chemical enrichment history. These results are discussed within two simple, contrasting hypotheses for the role played by AGN in galaxy evolution, which can be tested in the future at a greater detail with the use of larger data sets.

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arXiv2022

Unexplored outflows in nearby low luminosity AGNs: the case of NGC 1052

Outflows play a central role in galaxy evolution shaping the properties of galaxies. Understanding outflows and their effects in low luminosity AGNs, such as LINERs, is essential (e.g. they are a numerous AGN population in the local Universe). We obtained VLT/MUSE and GTC/MEGARA optical IFS-data for NGC1052, the prototypical LINER. The stars are distributed in a dynamically hot disc, with a centrally peaked velocity dispersion map and large observed velocity amplitudes. The ionised gas, probed by the primary component is detected up to $\sim$30arcsec ($\sim$3.3 kpc) mostly in the polar direction with blue and red velocities ($\mid$V$\mid$$<$250 km/s). The velocity dispersion map shows a notable enhancement ($σ$$>$90 km/s) crossing the galaxy along the major axis of rotation in the central 10arcsec. The secondary component has a bipolar morphology, velocity dispersion larger than 150 km/s and velocities up to 660 km/s. A third component is detected but not spatially resolved. The maps of the NaD absorption indicate optically thick neutral gas with a velocity field consistent with a slow rotating disc ($Δ$V = 77$\pm$12 km/s) but the velocity dispersion map is off-centred without any counterpart in the flux map. We found evidence of an ionised gas outflow with mass of 1.6$\pm$0.6 $\times$ 10$^{5}$ Msun, and mass rate of 0.4$\pm$0.2 Msun/yr. The outflow is propagating in a cocoon of gas with enhanced turbulence and might be triggering the onset of kpc-scale buoyant bubbles (polar emission). Taking into account the energy and kinetic power of the outflow (1.3$\pm$0.9 $\times$ 10$^{53}$ erg and 8.8$\pm$3.5 $\times$ 10$^{40}$ erg/s, respectively) as well as its alignment with both the jet and the cocoon, and that the gas is collisionally ionised, we consider that the outflow is jet-powered, although some contribution from the AGN is possible.

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arXiv2022

The diverse cold molecular gas contents, morphologies, and kinematics of type-2 quasars as seen by ALMA

We present CO(2-1) and adjacent continuum observations of 7 nearby radio-quiet type-2 quasars (QSO2s) obtained with ALMA at ~0.2" resolution (370 pc at z~0.1). The CO morphologies are diverse, including disks and interacting systems. Two of the QSO2s are red early-type galaxies with no CO(2-1) detected. In the interacting galaxies, the central kpc contains 18-25% of the total cold molecular gas, whereas in the spirals it is only 5-12%. J1010+0612 and J1430+1339 show double-peaked CO morphologies which do not have optical counterparts. Based on our analysis of the ionized and molecular kinematics and mm continuum emission, these CO morphologies are most likely produced by AGN feedback in the form of outflows, jets, and/or shocks. The CO kinematics of the QSO2s are dominated by rotation but also reveal noncircular motions. According to our analysis of the kinematics, these noncircular motions correspond to molecular outflows mostly coplanar with the CO discs in four of the QSO2s, and either to a coplanar inflow or vertical outflow in the case of J1010+0612. These outflows represent 0.2-0.7% of the QSO2s' total molecular gas mass and have maximum velocities of 200-350 km/s, radii from 0.4 to 1.3 kpc, and outflow rates of 8-16 Msun/yr. These properties are intermediate between those of the mild molecular outflows measured for Seyferts, and the fast and energetic outflows of ULIRGs. This suggests that it is not only AGN luminosity that drives massive molecular outflows. Other factors such as jet power, coupling between winds, jets, and/or ionized outflows and the CO discs, and amount or geometry of dense gas in the nuclear regions might be also relevant. Thus, although we do not find evidence for a significant impact of quasar feedback on the total molecular gas reservoirs and SFRs, it appears to be modifying the distribution of cold molecular gas in the central kpc of the galaxies.

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arXiv2022

Quantifying the cool ISM in radio AGNs: evidence for late-time re-triggering by galaxy mergers and interactions

We use deep Herschel observations of the complete 2Jy sample of powerful radio AGNs in the local universe (0.05 < z < 0.7) to probe their cool interstellar medium (ISM) contents and star-forming properties, comparing them against other samples of nearby luminous AGNs and quiescent galaxies. This allows us to investigate triggering and feedback mechanisms. We find that the dust masses of the strong-line radio galaxies (SLRGs) in our sample are similar to those of radio-quiet quasars, and that their median dust mass (Mdust = 2 x 10^7 Msun) is enhanced by a factor ~200 compared to that of non-AGN ellipticals, but lower by a factor ~16 relative to that of local ultra-luminous infrared galaxies (UILRGs). Along with compelling evidence for merger signatures in optical images, the SLRGs in our sample also show relatively high star-formation efficiencies, despite the fact that many of them fall below the main sequence for star forming galaxies. Together, these results suggest that most of our SLRGs have been re-triggered by late-time mergers that are relatively minor in terms of their gas contents. In comparison with the SLRGs, the radio AGNs with weak optical emission lines (WLRGs) and edge-darkened radio jets (FRIs) have both lower cool ISM masses and star-formation rates (by a factor of >30), consistent with being fuelled by a different mechanism (e.g. the direct accretion of hot gas).

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arXiv2021

Do AGN triggering mechanisms vary with radio power? II. The importance of mergers as a function of radio power and optical luminosity

Investigation of the triggering mechanisms of radio AGN is important for improving our general understanding of galaxy evolution. In the first paper in this series, detailed morphological analysis of high-excitation radio galaxies (HERGs) with intermediate radio powers suggested that the importance of triggering via galaxy mergers and interactions increases strongly with AGN radio power and weakly with optical emission-line luminosity. Here, we use an online classification interface to expand our morphological analysis to a much larger sample of 155 active galaxies (3CR radio galaxies, radio-intermediate HERGs and Type 2 quasars) that covers a broad range in both 1.4 GHz radio power and [OIII]$λ$5007 emission-line luminosity. All active galaxy samples are found to exhibit excesses in their rates of morphological disturbance relative to 378 stellar-mass- and redshift-matched non-active control galaxies classified randomly and blindly alongside them. These excesses are highest for the 3CR HERGs (4.7$σ$) and Type 2 quasar hosts (3.7$σ$), supporting the idea that galaxy mergers provide the dominant triggering mechanism for these subgroups. When the full active galaxy sample is considered, there is clear evidence to suggest that the enhancement in the rate of disturbance relative to the controls increases strongly with [OIII]$λ$5007 emission-line luminosity but not with 1.4 GHz radio power. Evidence that the dominant AGN host types change from early-type galaxies at high radio powers to late-type galaxies at low radio powers is also found, suggesting that triggering by secular, disk-based processes holds more importance for lower-power radio AGN.

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arXiv2021

Modeling the unresolved NIR-MIR SEDs of local ($z<0.1$) QSOs

To study the nuclear ($\lesssim1\,$kpc) dust of nearby ($z<0.1$) type 1 Quasi Stellar Objects (QSOs) we obtained new near-infrared (NIR) high angular resolution ($\sim0.3$ arcsec) photometry in the H and Ks bands, for 13 QSOs with available mid-infrared (MIR) high angular resolution spectroscopy ($\sim7.5-13.5\,μ$m). We find that in most QSOs the NIR emission is unresolved. We subtract the contribution from the accretion disk, which decreases from NIR ($\sim35\%$) to MIR ($\sim2.4\%$). We also estimate these percentages assuming a bluer accretion disk and find that the contibution in the MIR is nearly seven time larger. We find that the majority of objects ($64\%$, 9/13) are better fitted by the Disk+Wind H17 model \citep[][]{Hoenig17}, while others can be fitted by the Smooth F06 \citep[$14\%$, 2/13,][]{Fritz06}, Clumpy N08 \citep[$7\%$, 1/13,][]{Nenkova08a,Nenkova08b}, Clumpy H10 \citep[$7\%$, 1/13,][]{Hoenig10b}, and Two-Phase media S16 \citep[$7\%$, 1/13,][]{Stalev16} models. However, if we assume the bluer accretion disk, the models fit only 2/13 objects. We measured two NIR to MIR spectral indexes, $α_{NIR-MIR(1.6,8.7\,μ\text{m})}$ and $α_{NIR-MIR(2.2,8.7\,μ\text{m})}$, and two MIR spectral indexes, $α_{MIR(7.8, 9.8\,μ\text{m})}$ and $α_{MIR(9.8, 11.7\,μ\text{m})}$, from models and observations. From observations, we find that the NIR to MIR spectral indexes are $\sim-1.1$ and the MIR spectral indexes are $\sim-0.3$. Comparing the synthetic and observed values, we find that none of the models simultaneously match the measured NIR to MIR and $7.8-9.8\,μ$m slopes. However, we note that measuring the $α_{MIR(7.8, 9.8\,μ\text{m})}$ on the starburst-subtracted {\it Spitzer}/IRS spectrum, gives values of the slopes ($\sim-2$) that are similar to the synthetic values obtained from the models.

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arXiv2021

The Galaxy Activity, Torus and Outflow Survey (GATOS): II. Torus and polar dust emission in nearby Seyfert galaxies

We compare mid-IR and ALMA far-IR images of 12 nearby Seyferts selected from GATOS. The mid-IR unresolved emission contributes more than 60% of the nuclear emission in most galaxies. By contrast, the ALMA 870micron continuum emission is mostly resolved and typically along the torus equatorial direction (Paper I, Garcia-Burillo et al. 2021). The Eddington ratios and nuclear hydrogen column densities NH of half the sample are favorable to launching polar and/or equatorial dusty winds, according to simulations. Six show mid-IR extended emission in the polar direction as traced by the NLR and perpendicular to the ALMA emission. In a few, the nuclear NH might be too high to uplift large quantities of dusty material along the polar direction. Five galaxies have low NH and/or Eddington ratios and thus polar dusty winds are not likely. We generate new CAT3D-WIND disk-wind model images. At low wind-to-disk cloud ratios the far-IR model images have disk- and ring-like morphologies. The X-shape associated with dusty winds is seen better in the far-IR at intermediate-high inclinations for the extended-wind configurations. In most models, the mid-IR emission comes from the inner part of the disk/cone. Extended bi-conical and one-sided polar mid-IR emission is seen in extended-wind configurations and high wind-to-disk cloud ratios. When convolved to our resolution, the model images reproduce qualitative aspects of the observed morphologies. Low-intermediate wind-to-disk ratios are required to account for the large fractions of unresolved mid-IR emission. This work and Paper I provide observational support for the torus+wind scenario. The wind component is more relevant at high Eddington ratios and/or AGN luminosities, and polar dust emission is predicted at NH of up to $10^{24}$cm$^{-2}$. The torus/disk component, on the other hand, prevails at low luminosities and/or Eddington ratios. (Abridged)

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arXiv2021

The Galaxy Activity, Torus and Outflow Survey (GATOS) I. ALMA images of dusty molecular tori in Seyfert galaxies

We present the first results of the Galaxy Activity, Torus and Outflow Survey (GATOS), a project aimed at understanding the properties of the dusty molecular tori and their connection to the host galaxy in nearby Seyfert galaxies. Our project expands the range of AGN luminosities and Eddington ratios covered by previous surveys of Seyferts conducted by ALMA and allows us to study the gas feeding and feedback cycle in a combined sample of 19 Seyferts. We used ALMA to obtain new images of the emission of molecular gas and dust using the CO(3-2) and HCO+(4-3) lines as well as their underlying continuum emission at 870 microns with high spatial resolutions (0.1'' ~ 7 - 13 pc) in the CND of 10 nearby (D < 28 Mpc) Seyfert galaxies. Our new ALMA observations detect 870 micron continuum and CO line emission from spatially resolved disks located around the AGN in all the sources. The bulk of the continuum flux can be accounted for by thermal emission from dust in the majority of the targets. For most of the sources the disks show a preponderant orientation perpendicular to the AGN wind axes, as expected for dusty molecular tori. The median diameters and molecular gas masses of the tori are ~ 42 pc, and ~ 6 x 10**5 Msun, respectively. We find a positive correlation between the line-of-sight gas column densities responsible for the absorption of X-rays and the molecular gas column densities derived from CO towards the AGN in our sources. The radial distributions of molecular gas in the CND of our combined sample show signs of nuclear-scale molecular gas deficits. We also detect molecular outflows in the sources that show the most extreme nuclear-scale gas deficits in our sample. These observations find for the first time supporting evidence that the imprint of AGN feedback is more extreme in higher luminosity and/or higher Eddington ratio Seyfert galaxies.

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arXiv2021

The complex multi-component outflow of the Seyfert galaxy NGC 7130

AGN are a key ingredient for understanding galactic evolution. AGN-driven outflows are one of the manifestations of feedback. The AO mode for MUSE at the VLT permits to study the innermost tens of parsecs of nearby AGN in the optical. We present a detailed analysis of the ionised gas in the central regions of NGC 7130, an archetypical composite Seyfert and nuclear starburst galaxy. We achieve an angular resolution of 0.17$^{\prime\prime}$ (50 pc). We performed a multi-component analysis of the main ISM lines and identified nine kinematic components, six of which correspond to the outflow. The outflow is biconic and has velocities of a few $100\,{\rm km\,s^{-1}}$ with respect to the disc. We decompose the approaching side of the outflow into a broad and a narrow component with typical velocity dispersions below and above $\sim200\,{\rm km\,s^{-1}}$, respectively. The blueshifted narrow component has substructure, in particular a collimated plume aligned with the radio jet, indicating that it may be jet-powered. The redshifted lobe is composed of two Narrow Components and a Broad Component. An additional redshifted component is seen outside the main outflow axis. Line ratio diagnostics indicate that the outflow gas in the main axis is AGN-powered whereas the off-axis component has LINER properties. The ionised gas mass outflow rate is $\dot{M}=1.2\pm0.7\,M_{\odot}\,{\rm yr^{-1}}$ and the kinetic power is $\dot{E}_{\rm kin}=(2.7\pm2.0)\times10^{41}\,{\rm erg\,s^{-1}}$, which corresponds to $F_{\rm kin}=0.12\pm0.09\%$ of the bolometric AGN power. The combination of high angular resolution integral field spectroscopy and a careful multi-component decomposition allows a uniquely detailed view of the outflow in NGC 7130, illustrating that AGN kinematics are more complex than traditionally derived from less sophisticated data and analyses. (abridged)

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arXiv2020

Multi-phase feedback processes in the Sy2 galaxy NGC 5643

We study the multi-phase feedback processes in the central ~3 kpc of the barred Sy 2 galaxy NGC 5643. We use observations of the cold molecular gas (ALMA CO(2-1)) and ionized gas (MUSE IFU). We study different regions along the outflow zone which extends out to ~2.3 kpc in the same direction (east-west) as the radio jet, as well as nuclear/circumnuclear regions in the host galaxy disk. The deprojected outflowing velocities of the cold molecular gas (median Vcentral~189 km s^-1) are generally lower than those of the outflowing ionized gas, which reach deprojected velocities of up to 750 km s^-1 close to the AGN, and their spatial profiles follow those of the ionized phase. This suggests that the outflowing molecular gas in the galaxy disk is being entrained by the AGN wind. We derive molecular and ionized outflow masses of ~5.2x10^7 Msun and 8.5x10^4 Msun and molecular and ionized outflow mass rates of ~51 Msun yr^-1 and 0.14 Msun yr^-1. Therefore, the molecular phase dominates the outflow mass and outflow mass rate, while the outflow kinetic power and momentum are similar in both phases. However, the wind momentum load for the molecular and ionized outflow phases are ~27-5 and <1, which suggests that the molecular phase is not momentum conserving while the ionized one most certainly is. The molecular gas content (~1.5x10^7 Msun) of the eastern spiral arm is approximately 50-70% of the content of the western one. We interpret this as destruction/clearing of the molecular gas produced by the AGN wind impacting in the host galaxy. The increase of the molecular phase momentum implies that part of the kinetic energy from the AGN wind is transmitted to the molecular outflow. This suggest that in Sy-like AGN such as NGC 5643, the radiative/quasar and the kinetic/radio AGN feedback modes coexist and may shape the host galaxies even at kpc-scales via both positive and (mild) negative feedback.

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arXiv2020

Larger $λ_R$ in the disc of isolated active spiral galaxies than in their non-active twins

We present a comparison of the spin parameter $λ_R$, measured in a region dominated by the galaxy disc, between 20 pairs of nearby (0.005$<$z$<$0.03) seemingly isolated twin galaxies differing in nuclear activity. We find that 80--82% of the active galaxies show higher values of $λ_R$ than their corresponding non-active twin(s), indicating larger rotational support in the AGN discs. This result is driven by the 11 pairs of unbarred galaxies, for which 100% of the AGN show larger $λ_R$ than their twins. These results can be explained by a more efficient angular momentum transfer from the inflowing gas to the disc baryonic matter in the case of the active galaxies. This gas inflow could have been induced by disc or bar instabilities, although we cannot rule out minor mergers if these are prevalent in our active galaxies. This result represents the first evidence of galaxy-scale differences between the dynamics of active and non-active isolated spiral galaxies of intermediate stellar masses (10$^{10}<M_*<10^{11}$ M$_{\odot}$) in the Local Universe.

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arXiv2020

Cold molecular gas and PAH emission in Seyfert galaxies

We investigate the relation between the detection of the $11.3\,μ$m PAH feature in the nuclear ($\sim 24-230\,$pc) regions of 22 nearby Seyfert galaxies and the properties of the cold molecular gas. For the former we use ground-based (0.3-0.6" resolution) mid-infrared (mid-IR) spectroscopy. The cold molecular gas is traced by ALMA and NOEMA high (0.2-1.1") angular resolution observations of the CO(2-1) transition. Galaxies with a nuclear detection of the $11.3\,μ$m PAH feature contain more cold molecular gas (median $1.6\times 10^7\,M_\odot$) and have higher column densities ($N({\rm H}_2) = 2 \times 10^{23}\,{\rm cm}^{-2}$) over the regions sampled by the mid-IR slits than those without a detection. This suggests that molecular gas plays a role in shielding the PAH molecules in the harsh environments of Seyfert nuclei. Choosing the PAH molecule naphthalene as an illustration, we compute its half-life in the nuclear regions of our sample when exposed to 2.5keV hard X-ray photons. We estimate shorter half-lives for naphthalene in nuclei without a $11.3\,μ$m PAH detection than in those with a detection. The Spitzer/IRS PAH ratios on circumnuclear scales ($\sim$ 4" $\sim$ 0.25-1.3kpc) are in between model predictions for neutral and partly ionized PAHs. However, Seyfert galaxies in our sample with the highest nuclear H$_2$ column densities are not generally closer to the neutral PAH tracks. This is because in the majority of our sample galaxies, the CO(2-1) emission in the inner $\sim$ 4" is not centrally peaked and in some galaxies traces circumnuclear sites of strong star formation activity. Spatially resolved observations with the MIRI medium-resolution spectrograph (MRS) on the James Webb Space Telescope will be able to distinguish the effects of an active galactic nucleus (AGN) and star formation on the PAH emission in nearby AGN.

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arXiv2020

Searching for molecular gas in/outflows in the nuclear regions of five Seyfert galaxies

AGN-driven outflows are believed to play an important role in regulating the growth of galaxies mostly via negative feedback. However, their effects on their hosts are far from clear, especially for low and moderate luminosity Seyferts. To investigate this issue, we have obtained cold molecular gas observations, traced by the CO(2-1) transition, using the NOEMA interferometer of five nearby (distances between 19 and 58 Mpc) Seyfert galaxies. The resolution of approx. 0.3-0.8 arcsec (approx. 30-100 pc) and field of view of NOEMA allowed us to study the CO(2-1) morphology and kinematics in the nuclear regions (approx. 100 pc) and up to radial distances of approx. 900 pc. We have detected CO(2-1) emission in all five galaxies with disky or circumnuclear ring like morphologies. We derived cold molecular gas masses on nuclear (approx. 100 pc) and circumnuclear (approx. 650 pc) scales in the range from $10^6$ to $10^7$M$_{\odot}$ and from $10^7$ to $10^8$ $M_{\odot}$, respectively. In all of our galaxies the bulk of this gas is rotating in the plane of the galaxy. However, non-circular motions are also present. In NGC 4253, NGC 4388 and NGC 7465, we can ascribe the streaming motions to the presence of a large-scale bar. In Mrk 1066 and NGC 4388, the non-circular motions in the nuclear regions are explained as outflowing material due to the interaction of the AGN wind with molecular gas in the galaxy disk. We conclude that for an unambiguous and precise interpretation of the kinematics of the cold molecular gas we need a detailed knowledge of the host galaxy (i.e., presence of bars, interactions, etc) as well as of the ionized gas kinematics and the ionization cone geometry.

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arXiv2020

Modelling the strongest silicate emission features of local type 1 AGN

We measure the 10 and $18μ$m silicate features in a sample of 67 local ($z<0.1$) type 1 active galactic nuclei (AGN) with available {\it Spitzer} spectra dominated by non-stellar processes. We find that the $10μ$m silicate feature peaks at $10.3^{+0.7}_{-0.9}μ$m with a strength (Si$_{p}$ = ln f$_{p}$(spectrum)/f$_{p}$(continuum)) of $0.11^{+0.15}_{-0.36}$, while the $18μ$m one peaks at $17.3^{+0.4}_{-0.7}μ$m with a strength of $0.14^{+0.06}_{-0.06}$. We select from this sample sources with the strongest 10$μ$m silicate strength ($σ_{Si_{10μm}}>0.28$, 10 objects). We carry out a detailed modeling of the IRS/{\it Spitzer} spectra by comparing several models that assume different geometries and dust composition: a smooth torus model, two clumpy torus models, a two-phase medium torus model, and a disk+outflow clumpy model. We find that the silicate features are well modeled by the clumpy model of Nenkova et al. 2008, and among all models those including outflows and complex dust composition are the best (Hoenig et al. 2017). We note that even in AGN-dominated galaxies it is usually necessary to add stellar contributions to reproduce the emission at the shortest wavelengths.

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arXiv2019

ALMA images the many faces of the NGC1068 torus and its surroundings

We investigate the fueling and the feedback of nuclear activity in the Seyfert 2 galaxy NGC1068, by studying the distribution and kinematics of molecular gas in the torus and its connections. We use ALMA to image the emission of a set of molecular gas tracers in the circumnuclear disk (CND) and the torus of the galaxy using the CO(2-1), CO(3-2) and HCO+(4-3) lines with spatial resolutions ~0.03"-0.09"(2-6pc). ALMA resolves the CND as an asymmetric ringed disk of D~400pc-size and mass of ~1.4x10^8 Msun. The inner edge of the ring is associated with edge-brightened arcs of NIR polarized emission identified with the working surface of the AGN ionized wind. ALMA proves the existence of a molecular torus of M_torus ~ 3x10^5Msun, which extends over a large range of spatial scales D=10-30pc around the central engine. The new observations evidence the density radial stratification of the torus: the HCO+(4-3) torus, with a full size D=11pc, is a factor of 2-3 smaller than its CO(2-1) and CO(3-2) counterparts, which have full-sizes D=26pc and D=28pc, respectively. The torus is connected to the CND through a network of gas streamers. The kinematics of molecular gas show strong departures from circular motions in the torus, the gas streamers, and the CND. These velocity distortions are interconnected and are part of a 3D outflow that reflects the effects of AGN feedback on the kinematics of molecular gas across a wide range of spatial scales. We conclude that a wide-angle AGN wind launched from the accretion disk is impacting a sizeable fraction of the gas inside the torus (~0.4-0.6 x M_torus). However, a large gas reservoir (~1.2-1.8 x 10^5Msun) close to the equatorial plane of the torus remains unaffected by the AGN wind and can continue fueling the AGN for ~1-4Myr. AGN fueling seems nevertheless thwarted on intermediate scales (15pc < r < 50pc).

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arXiv2019

Exploring the mid-infrared SEDs of six AGN dusty torus models II: the data

This is the second in a series of papers devoted to explore a set of six dusty models of active galactic nuclei (AGN) with available spectral energy distributions (SEDs). These models are the smooth torus by Fritz et al. (2006), the clumpy torus by Nenkova et al. (2008B), the clumpy torus by Hoenig & Kishimoto (2010), the two phase torus by Siebenmorgen et al. (2015), the two phase torus by Stalevski et al. (2016), and the wind model by Hoenig & Kishimoto (2017). The first paper explores discrimination among models and the parameter restriction using synthetic spectra (Gonzalez-Martin et al. 2019A). Here we perform spectral fitting of a sample of 110 AGN drawn from the Swift/BAT survey with Spitzer/IRS spectroscopic data. The aim is to explore which is the model that describes better the data and the resulting parameters. The clumpy wind-disk model by Hoenig & Kishimoto (2017) provides good fits for ~50% of the sample, and the clumpy torus model by Nenkova et al. (2008B) is good at describing ~30% of the objects. The wind-disk model by Hoenig & Kishimoto (2017) is better for reproducing the mid-infrared spectra of Type-1 Seyferts while Type-2 Seyferts are equally fitted by both models. Large residuals are found irrespective of the model used, indicating that the AGN dust continuum emission is more complex than predicted by the models or that the parameter space is not well sampled. We found that all the resulting parameters for our AGN sample are roughly constrained to 10-20% of the parameter space. The derived outer radius of the torus is smaller for the smooth torus by Fritz et al. (2006) and the two phase torus by Stalevski et al. (2016) than the one derived from the clumpy torus by (Nenkova et al. 2008B). Covering factors and line-of-sight viewing angles strongly depend on the model used. The total dust mass is the most robust derived quantity.

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