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The incoming generation of the 30-40 meter-class telescopes will enable resolving the stellar kinematics of high redshift galaxies. In particular, the High Angular Resolution Monolithic Optical and Near-infrared Integral field spectrograph (HARMONI) for the Extremely Large Telescope (ELT) could likely resolve the stellar kinematics of galaxies around cosmic noon with similar spatial and velocity resolutions to current studies for nearby and intermediate redshift galaxies. We have simulated HARMONI observations of type I AGNs at redshift 1.5, using the 20x20 mas2 spatial scale and LTAO working at 0’’.67 seeing. We used MUSE observations of a nearby galaxy to create the input targets for the HARMONI simulation pipeline (HSIM). In this work, we present the results of these simulations highlighting the capabilities of HARMONI to unveil the stellar morpho-kinematic properties of type I AGNs around cosmic noon, performing a de-blending of the AGN and host galaxy spectra., This work is part of the Participation of the Instituto de Astrofísica de Canarias in the development of the HARMONI instrument for the Extremely Large Telescope. See HARMONI at the IAC (https://www.iac.es/es/proyectos/harmoni)

We measure the 10 and $18\mu$m silicate features in a sample of 67 local ($z0.28$, 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., Comment: Accepted for publication in ApJ

We investigate the relation between the detection of the 11.3 μm polycyclic aromatic hydrocarbon (PAH) feature in the nuclear (∼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 μm PAH feature contain more cold molecular gas (median 1.6 × 107 MO ) and have higher column densities (N(H2) = 2 × 1023 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 2.5 keV hard X-ray photons. We estimate shorter half-lives for naphthalene in nuclei without a 11.3 μm PAH detection than in those with a detection. The Spitzer/IRS PAH ratios on circumnuclear scales (∼4″ ∼ 0.25-1.3 kpc) are in between model predictions for neutral and partly ionized PAHs. However, Seyfert galaxies in our sample with the highest nuclear H2 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 ∼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 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., With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737)

Context. In recent decades, several multiwavelength studies have been dedicated to exploring the properties of the obscuring material in active galactic nuclei (AGN). Various models have been developed to describe the structure and distribution of this material and constrain its physical and geometrical parameters through spectral fitting techniques. However, questions around the way in which torus mid-infrared (mid-IR) and X-ray emission are related remain unanswered. Aims. In this work, we aim to study whether the dust continuum at mid-IR and gas reflection at X-rays have the same distribution in a sample of AGN. Methods. We carefully selected a sample of 36 nearby AGN with NuSTAR and Spitzer spectra available that satisfy the following criteria: (1) the AGN component dominates the mid-IR spectra (i.e., the stellar and interstellar medium components contribute less than 50% to the spectrum), and (2) the reflection component contributes significantly to the X-ray spectrum. Furthermore, we discarded the sources whose reflection component could be produced by ionized material in the disk. We derived the properties of the nuclear dust and gas through a spectral fitting, using models developed for mid-IR and X-ray wavelengths assuming smooth and clumpy distributions for this structure. Results. We find that a combination of smooth and clumpy distributions of gas and dust, respectively, is preferred for ∼80% of sources with good spectral fits according to the Akaike criterion. However, considering extra information about each individual source, such as the absorption variability, we find that ∼50% of our sources are best described by a clumpy distribution of both dust and gas. The remaining ∼50% of our sources can still be explained with a smooth distribution of gas and a clumpy distribution of dust. Furthermore, we explored the torus dust-to-gas ratio, finding that it is [0.01–1] times that of the interstellar medium. Conclusions. The results presented in this paper suggest that the distribution of the gas and dust in AGN is complex. We find at least six scenarios to explain the observed properties of our sample. In these scenarios, three gas–dust distribution combinations are possible: clumpy–clumpy, smooth–smooth, and smooth–clumpy. Most of them are in agreement with the notion that gas could also be located in the dust-free region, which is consistent with the dust-to-gas ratio found. © ESO 2021., This work made use of data from the NuSTAR mission, a project led by CalTech, managed by JPL, and funded by NASA. We thank the NuSTAR Operations, Software and Calibration teams for support with the execution and analysis of these observations. This research has made use of the NuSTAR Data Analysis Software (NuSTAR-DAS) jointly developed by the ASI Science Data Center (ASDC, Italy) and CalTech. This work is based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. D.E.-A. and N.O.-C. acknowledge support from a CONACYT scholarship. This research is mainly funded by the UNAM PAPIIT projects IN105720 and IA113719 (PI O.G.-M. and PI D.D.). J.M. acknowledges financial support by the Spanish Ministry of Economy and Competitiveness (MEC) under grant no. AYA2016-76682-C3 and from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award to the Instituto de Astrofisica de Andalucia (SEV-2017-0709). C.R.-A. acknowledges financial support from the Spanish Ministry of Science, Innovation and Universities (MCIU) under grant with reference RYC-2014-15779, from the European Union's Horizon 2020 research and innovation programme under Marie Sklodowska-Curie grant agreement No 860744 (BiD4BESt), from the State Research Agency (AEI-MCINN) of the Spanish MCIU under grants "Feeding and feedback in active galaxies" with reference PID2019-106027GB-C4 and "Quantifying the impact of quasar feedback on galaxy evolution (QSOFEED)" with reference EUR2020-112266. CRA also acknowledges support from the Consejeria de Economia, Conocimiento y Empleo del Gobierno de Canarias and the European Regional Development Fund (ERDF) under grant with reference ProID2020010105 and from IAC project P/301404, financed by the Ministry of Science and Innovation, through the State Budget and by the Canary Islands Department of Economy, Knowledge and Employment, through the Regional Budget of the Autonomous Community. I.G.-B. acknowledges support from STFC through grant ST/S000488 1.

Physical processes such as re-ignition, enhancement, and fading of active galactic nuclei (AGN) are not entirely understood because the timeline of these events is expected to last many years. However, it is well known that the differences in the energy budget between AGN components, like the optical ionizing region and the mid-infrared (MIR) dust echoes, can be interpreted as a hint on AGN evolution. Here we present a catalog of 88 AGN candidates showing hints on the fading and rising of their activity in the nearby Universe. We use AGN scaling relations to select them from an initial sample of 877 candidates using publicly available optical, X-ray, and MIR luminosities. We then use the multi-wavelength information to discard sources contaminated with extranuclear emission and those with an X-ray luminosity not well corrected for absorption. We find that 96% of our candidates are fading sources. This result suggests a scenario where the Universe had its peak of AGN activity somewhere in the past and is dominated by a fading phase at the present time. Alternatively, the fading phase is longer than the rising phase, which is consistent with galaxy merger simulations. Around 50% of these fading candidates are associated with merging or interacting systems. Finally, we also find the existence of jets in ~30% of these candidates and that the preferred AGN dust geometry is torus-like, instead of wind-like. Our results are compatible with the fading of nuclear activity, expected if they are in an inefficient state., Comment: Accepted for publication in ApJ, 22 pages, 17 figures, and 5 tables

We study the detectability of the emission associated with the AGN dusty structure at sub-mm wavelengths using ALMA, in a theoretical and observational way. Theoretically, we use the Clumpy models from Nenkova et al. together with the mid-infrared to X-ray and the radio fundamental plane scaling relations. We find that it is more likely to detect bigger and denser dusty tori at the highest ALMA frequency (666 GHz/450 micron). We also find that with 1h at 353 GHz/850 micron and 10h at 666 GHz/450 micron we can detect, with a high detection limit, a 1 mJy torus (characteristic of bright AGN). This means, an object for which the unresolved SED at 12 micron has a flux ~1mJy. Observationally, we use four prototypical AGN: NGC\,1052 (low-luminosity AGN), NGC\,1068 (Type-2), NGC\,3516 (Type 1.5), and IZw1 (QSO), with radio, sub-millimeter, and mid-IR data available. All the mid-infrared spectra are best fit with the smooth model reported by Fritz et al. A power law and a single, or a composition of, synchrotron component/s reproduce the cm radio wavelengths. We combined and extrapolated both fits to compare the extrapolation of both torus and jet contributors at sub-mm wavelengths with data at these wavelengths. Our observational results are consistent with our theoretical results. The most promising candidate to detect the torus is the QSO IZw1 (therefore, highly accreting sources in general), although it cannot be resolved due to the distance of this source. We suggest that to explore the detection of a torus at sub-mm wavelengths, it is necessary to perform an SED analysis including radio data, with particular attention to the angular resolution., Comment: Accepted for publication in ApJ

At distances from the active galaxy nucleus where the ambient temperature falls below ∼1500-1800 K, dust is able to survive. It is thus possible to have a large dusty structure present that surrounds the active galaxy nucleus. This is the first of two papers aiming at comparing six dusty torus models with available spectral energy distributions, namely, Fritz et al., Nenkova et al., Hönig & Kishimoto, Siebenmorgen et al., Stalevski et al., and Hönig & Kishimoto. In this first paper we use synthetic spectra to explore the discrimination between these models and under which circumstances they allow us to restrict the torus parameters, while our second paper analyzes the best model to describe the mid-infrared spectroscopic data. We have produced synthetic spectra from current instruments GTC/CanariCam and Spitzer/IRS and future James Webb Space Telescope (JWST)/MIRI and JWST/NIRSpec instruments. We find that for a reasonable brightness (F > 100 mJy) we can actually distinguish among models except for the two pairs of parent models. We show that these models can be distinguished based on the continuum slopes and the strength of the silicate features. Moreover, their parameters can be constrained within 15% of error, irrespective of the instrument used, for all the models except Hönig & Kishimoto. However, the parameter estimates are ruined when more than 50% of circumnuclear contributors are included. Therefore, future high spatial resolution spectra such as those expected from JWST will provide enough coverage and spatial resolution to tackle this topic.© 2019 The American Astronomical Society. All rights reserved., This research is mainly funded by the UNAM PAPIIT project IA103118 (PI OG-M). M.M.-P. acknowledges support by KASI postdoctoral fellowships. I.M. and J.M. acknowledge financial support from the research project AYA2016-76682-C3-1-P (AEI/FEDER, UE). J.M.R.-E. acknowledges support from the Spanish Ministry of Science under grants AYA2015-70498-C2-1 and AYA2017-84061-P. I.G.-B. acknowledges financial support from the Spanish Ministry of Science and Innovation (MICINN) through projects PN AYA2015-64346-C2-1-P and AYA2016-76682-C3-2-P. I.M. and J.M. acknowledge financial support from the State Agency for Research of the Spanish MCIU through the >Center of Excellence Severo Ochoa> award for the Instituto de Astrofisica de Andalucia (SEV-2017-0709). D.E.-A. acknowledges support from a CONACYT scholarship. D.-D. acknowledges PAPIIT UNAM support from grant IN113719.

We propose the use of quasars with accretion rate near the Eddington ratio (extreme quasars) as standard candles. The selection criteria are based on the Eigenvector 1 (E1) formalism. Our first sample is a selection of 334 optical quasar spectra from the SDSS DR7 database with a S/N > 20. Using the E1, we define primary and secondary selection criteria in the optical spectral range. We show that it is possible to derive a redshift-independent estimate of luminosity for extreme Eddington ratio sources. Our results are consistent with concordance cosmology but we need to work with other spectral ranges to take into account the quasar orientation, among other constrains.

In order to understand the diversity of classes observed in active galactic nuclei (AGNs), a geometrically and optically thick torus of gas and dust is required to obscure the central engine depending on the line of sight to the observer. We perform a simultaneous fitting of X-ray and mid-infrared (mid-IR) spectra to investigate whether the same structure could produce both emissions and, if this the case, to obtain better constraints for the physical parameters of the torus. In this case we take advantage of the fact that both emissions show important signatures of obscuration. We used the nearby type 2 active nucleus IC 5063 as a test object. This object is ideal because of the wealth of archival data, including some high-resolution data. It also has a relatively high AGN luminosity that dominates at both X-ray and mid-IR frequencies. We use high spectral resolution NuSTAR and Spitzer/IRS spectra. The AGN dusty models used several physically motivated models. We found that the combination of the smooth torus models at mid-IR by Fritz et al. and at X-rays by Baloković et al., with the viewing and half-opening angles linked to the same value, is the best choice to fit the spectra at both wavelengths. This allows us to determine all the parameters of its torus. This result suggests that the structure producing the continuum emission at mid-IR and the reflection component at X-ray is the same. Therefore, we prove that this technique can be used to infer the physical properties of the torus, at least when AGN dust dominates the mid-IR emission and the reflection component is significant at X-rays. © 2019. The American Astronomical Society. All rights reserved., D.E.-A. acknowledges support from a CONACYT scholarship. This research is mainly funded by the UNAM PAPIIT project IA103118 (PI OG-M). M.M.-P. acknowledges support from KASI postdoctoral fellowships. J.M. acknowledges financial support from the research project AYA2016-76682-C3-1-P (AEI/FEDER, UE) and the State Agency for Research of the Spanish MCIU through the Center of Excellence Severo Ochoa award for the Instituto de Astrofísica de Andalucía (SEV-2017-0709). C.R.-A. acknowledges the Ramón y Cajal Program of the Spanish Ministry of Economy and Competitiveness through project RYC-2014-15779 and the Spanish Plan Nacional de Astronomía y Astrofisíca under grant AYA2016-76682-C3-2-P.

This is the second in a series of papers devoted to exploring a set of six dusty models of active galactic nuclei (AGN) with available spectral energy distributions. These models are the smooth torus by Fritz et al., the clumpy torus by Nenkova et al., the clumpy torus by Hönig & Kishimoto, the two-phase torus by Siebenmorgen et al., the two-phase torus by Stalevski et al., and the wind model by Hönig & Kishimoto. The first paper explores discrimination among models and the parameter restriction using synthetic spectra. 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 Hönig & Kishimoto provides good fits for ∼50% of the sample, and the clumpy torus model by Nenkova et al. is good at describing ∼30% of the objects. The wind-disk model by Hönig & Kishimoto is better for reproducing the mid-infrared spectra of type 1 Seyferts (with 60% of the type 1 Seyferts well reproduced by this model compared to the 10% well represented by the clumpy torus model by Nenkova et al.), while type 2 Seyferts are equally fitted by both models (roughly 40% of the type 2 Seyferts). 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. Contrary to what is generally assumed, the derived outer radius of the torus is smaller (reaching up to a factor of ∼5 smaller for 10 pc tori) for the smooth torus by Fritz et al. and the two-phase torus by Stalevski et al. than the one derived from the clumpy torus by Nenkova et al. Covering factors and line-of-sight viewing angles strongly depend on the model used. The total dust mass is the most robust derived quantity, giving equivalent results for four of these models.© 2019 The American Astronomical Society. All rights reserved., This research is mainly funded by the UNAM PAPIIT project IA103118 (PI OG-M). M.M.-P. acknowledges support by KASI postdoctoral fellowships. I.M. and J.M. acknowledge financial support from the research project AYA2016-76682-C3-1-P (AEI/FEDER, UE). J.M.R.-E. acknowledges support from the Spanish Ministry of Science under grants AYA2015-70498-C2-1 and AYA2017-84061-P. I.G.-B. acknowledges financial support from the Spanish Ministry of Science and Innovation (MICINN) through projects PN AYA2015-64346-C2-1-P and AYA2016-76682-C3-2-P. I.M. and J.M. acknowledge financial support from the State Agency for Research of the Spanish MCIU through the >Center of Excellence Severo Ochoa> award for the Instituto de Astrofisica de Andalucia (SEV-2017-0709). D.E.-A. acknowledges support from a CONACYT scholarship. D.-D. acknowledges PAPIIT UNAM support from grant IN113719.

We studied the circumnuclear MIR emission in a sample of 19 local active galactic nuclei (AGN) with high spatial resolution spectra using T-ReCS (Gemini) and CanariCam (GTC), together with IRS/Spitzer observations. We measured the flux and the equivalent width for the 11.3 micron PAH feature and the [SIV] line emission as a function of galactocentric distance. This allowed to study the star formation (SF) at sub-kpc scales from the nucleus for a large sample of nearby AGN. The [SIV] line emission could be tracing the AGN radiation field within a few thousand times the sublimation radius (R_sub), but it often peaks at distances greater than 1000 R_sub. One possibility is that the SF is contributing to the [SIV] total flux. We found an 11.3 micron PAH emission deficit within the inner few tens of parsecs from the AGN. This deficit might be due to the destruction of the molecules responsible for this feature or the lack of SF at these distances. We found a sensible agreement in the expected shift of the relation of the AGN bolometric luminosity and the SF rate. This indicates that numerical models attributing the link between AGN activity and host galaxy growth to mergers are in agreement with our data, for most inner galaxy parts., 16 pages in the main body of the text, 6 figures, accepted for publication in APJ