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This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited., We present the first very long baseline interferometric (VLBI) observations of the blazar OJ 287 carried out jointly with the Global Millimeter VLBI Array (GMVA) and the phased Atacama Large Millimeter/submillimeter Array (ALMA) at 3.5 mm on 2017 April 2. The participation of phased ALMA has not only improved the GMVA north–south resolution by a factor of ∼3, but has also enabled fringe detections with signal-to-noise ratios up to 300 at baselines longer than 2 Gλ. The high sensitivity has motivated us to image the data with newly developed regularized maximum likelihood imaging methods, revealing the innermost jet structure with unprecedentedly high angular resolution. Our images reveal a compact and twisted jet extending along the northwest direction, with two bends within the inner 200 μas, resembling a precessing jet in projection. The component at the southeastern end shows a compact morphology and high brightness temperature, and is identified as the VLBI core. An extended jet feature that lies at ∼200 μas northwest of the core shows a conical shape, in both total and linearly polarized intensity, and a bimodal distribution of the linear polarization electric vector position angle. We discuss the nature of this feature by comparing our observations with models and simulations of oblique and recollimation shocks with various magnetic field configurations. Our high-fidelity images also enabled us to search for possible jet features from the secondary supermassive black hole (SMBH) and test the SMBH binary hypothesis proposed for this source. © 2022. The Author(s). Published by the American Astronomical Society., The work at the IAA-CSIC is supported in part by the Spanish Ministerio de Economía y Competitividad (grants AYA2016-80889-P and PID2019-108995GB-C21), the Consejería de Economía, Conocimiento, Empresas y Universidad of the Junta de Andalucía (grant P18-FR-1769), the Consejo Superior de Investigaciones Científicas (grant 2019AEP112), and the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709). This publication acknowledges the project M2FINDERS, which is funded by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No. 101018682). L.L. acknowledges the support of the DGAPA/PAPIIT grants IN112417 and IN112820, the CONACyT-AEM grant 275201, and the CONACyT-CF grant 263356. T.S. was supported by the Academy of Finland projects 274477, 284495, 312496, and 315721. Y.K. was supported in the framework of the State project "Science" by the Ministry of Science and Higher Education of the Russian Federation, under the contract 075-15-2020-778. J.Y.K acknowledges support from the National Research Foundation of Korea (grant no. 2022R1C1C1005255). R.-S. L is supported by the Max Planck Partner Group of the MPG and the CAS, the Key Program of the National Natural Science Foundation of China (grant No. 11933007), the Key Research Program of Frontier Sciences, CAS (grant No. ZDBS-LY-SLH011), and the Shanghai Pilot Program for Basic Research – Chinese Academy of Science, Shanghai Branch (JCYJ-SHFY-2022-013).

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited., We present Very Large Array (VLA) and Atacama Large Millimeter/submillimeter Array (ALMA) observations of the close (0farcs3 = 90 au separation) protobinary system SVS 13. We detect two small circumstellar disks (radii ∼12 and ∼9 au in dust, and ∼30 au in gas) with masses of ∼0.004–0.009 M☉ for VLA 4A (the western component) and ∼0.009–0.030 M☉ for VLA 4B (the eastern component). A circumbinary disk with prominent spiral arms extending ∼500 au and a mass of ∼0.052 M☉ appears to be in the earliest stages of formation. The dust emission is more compact and with a very high optical depth toward VLA 4B, while toward VLA 4A the dust column density is lower, allowing the detection of stronger molecular transitions. We infer rotational temperatures of ∼140 K, on scales of ∼30 au, across the whole source, and a rich chemistry. Molecular transitions typical of hot corinos are detected toward both protostars, being stronger toward VLA 4A, with several ethylene glycol transitions detected only toward this source. There are clear velocity gradients, which we interpret in terms of infall plus rotation of the circumbinary disk, and pure rotation of the circumstellar disk of VLA 4A. We measured orbital proper motions and determined a total stellar mass of 1 M☉. From the molecular kinematics, we infer the geometry and orientation of the system, and stellar masses of ∼0.26 M☉ for VLA 4A and ∼0.60 M☉ for VLA 4B. © 2022. The Author(s). Published by the American Astronomical Society., G.A., G.B.-C., I.dG.-M., A.K.D.-R., R.E., G.A.F., J.F.G., M.O., and J.M.T. acknowledge support from the Spanish MINECO/AEI through the AYA2017-84390-C2 grant (co-funded by FEDER) and MCIN/AEI/10.13039/501100011033 through the PID2020-114461GB-I00 and PID2020-117710G-I00 grants. G.A., G.B.-C., A.K.D.-R., G.A.F., J.F.G., and M.O. 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 Astrofísica de Andalucía (SEV-2017-0709). G.B.-C. also acknowledges support from the Spanish MICINN/AEI through the PRE2018-086111 (SEV-2017-0709-18-1) grant (co-funded by ESF). G.A.F also acknowledges support from the Collaborative Research Centre 956, funded by the Deutsche Forschungsgemeinschaft (DFG) project ID 184018867. L.A.Z. acknowledges financial support from CONACyT-280775 and UNAM-PAPIIT IN110618 grants, México. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2015.1.01229.S, ADS/JAO.ALMA#2016.1.01305.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada) and NSC and ASIAA (Taiwan) and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO, and NAOJ. Based on analysis carried out with the CASSIS software (Vastel et al. 2015) and JPL, CDMS, and VASTEL databases. CASSIS has been developed by IRAP-UPS/CNRS. This research made use of Astropy a community-developed core Python package for Astronomy (Astropy Collaboration et al. 2013, 2018).

We present Atacama Large Millimeter/submillimeter Array (ALMA) and Karl G. Jansky Very Large Array (JVLA) observations of the massive infrared dark cloud NGC 6334S (also known as IRDC G350.56+0.44), located at the southwestern end of the NGC 6334 molecular cloud complex. The H$^{13}$CO$^{+}$ and the NH$_{2}$D lines covered by the ALMA observations at a $\sim$3$^{\prime\prime}$ angular resolution ($\sim$0.02 pc) reveal that the spatially unresolved non-thermal motions are predominantly subsonic and transonic, a condition analogous to that found in low-mass star-forming molecular clouds. The observed supersonic non-thermal velocity dispersions in massive star forming regions, often reported in the literature, might be significantly biased by poor spatial resolutions that broaden the observed line widths due to unresolved motions within the telescope beam. Our 3~mm continuum image resolves 49 dense cores, whose masses range from 0.17 to 14 $M_{\odot}$. The majority of them are resolved with multiple velocity components. Our analyses of these gas velocity components find an anti-correlation between the gas mass and the virial parameter. This implies that the more massive structures tend to be more gravitationally unstable. Finally, we find that the external pressure in the NGC 6334S cloud is important in confining these dense structures, and may play a role in the formation of dense cores, and subsequently, the embedded young stars., 30 pages, 10 figures, 2 tables, accepted for publication in The Astrophysical Journal

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.

Here we present deep (16 μJy beam), very high (40 mas) angular resolution 1.14 mm, polarimetric, Atacama Large Millimeter/submillimeter Array (ALMA) observations toward the massive protostar driving the HH 80-81 radio jet. The observations clearly resolve the disk oriented perpendicularly to the radio jet, with a radius of ≃0.″171 (∼291 au at 1.7 kpc distance). The continuum brightness temperature, the intensity profile, and the polarization properties clearly indicate that the disk is optically thick for a radius of R ≲ 170 au. The linear polarization of the dust emission is detected almost all along the disk, and its properties suggest that dust polarization is produced mainly by self-scattering. However, the polarization pattern presents a clear differentiation between the inner (optically thick) part of the disk and the outer (optically thin) region of the disk, with a sharp transition that occurs at a radius of ∼0.″1 (∼170 au). The polarization characteristics of the inner disk suggest that dust settling has not occurred yet with a maximum dust grain size between 50 and 500 μm. The outer part of the disk has a clear azimuthal pattern but with a significantly higher polarization fraction compared to the inner disk. This pattern is broadly consistent with the self-scattering of a radiation field that is beamed radially outward, as expected in the optically thin outer region, although contribution from non-spherical grains aligned with respect to the radiative flux cannot be excluded.© 2018. The American Astronomical Society. All rights reserved.., This paper makes use of the following ALMA data: ADS/ JAO.ALMA#2015.1.00480.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada) and NSC and ASIAA (Taiwan) and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. J.M.G., R.E., G.A., N.A.L., G.B., J.F.G., M.O., and J.M.T. are supported by the MINECO (Spain) AYA2014-57369-C3 and AYA2017-84390-C2 coordinated grants. S.C. acknowledges support from DGAPA, UNAM, and CONACyT, Mexico. H.Y. is supported in part by ALMA SOS, and Z.L.Y. by NASA NNX14AB38G and NSF AST-1313083 and 1715259. M.P. acknowledges funding from the European Unions Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 664931. I.J.S. acknowledges financial support from STFC through an Ernest Rutherford Fellowship (ST/L004801). J.M. acknowledges support from MINECO (Spain) AYA2016-76012-C3-3-P grant.

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 study dust concentration in axisymmetric gas rings in protoplanetary disks. Given the gas surface density, we derived an analytical total dust surface density by taking into account the differential concentration of all grain sizes. This model allows us to predict the local dust-to-gas mass ratio and the slope of the particle size distribution, as a function of radius. We test this analytical model by comparing it with a 3D magnetohydrodynamical simulation of dust evolution in an accretion disk. The model is also applied to the disk around HD 169142. By fitting the disk continuum observations simultaneously at λ = 0.87, 1.3, and 3.0 mm, we obtain a global dust-to-gas mass ratio and a viscosity coefficient α = 1.35 × 10. This model can be easily implemented in numerical simulations of accretion disks.© 2019. The American Astronomical Society. All rights reserved., A.S. and S.L. acknowledge support from PAPIIT-UNAM IN101418 and CONACyT 23863. M.O. is supported by the MINECO (Spain) AYA2014-57369-C3 and AYA2017-84390-C2 grants (co-funded by FEDER). M.O. acknowledges 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). M.F. acknowledges funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No. 757957).

17 pags., 6 figs., 10 tabs. -- Unified Astronomy Thesaurus concepts: Molecular physics (2058); Molecule formation (2076); Molecular spectroscopy (2095), Gas phase formation processes feasible at low temperatures are determined theoretically for 38 isomers obeying the C3O3H6 empirical formula, one of them, the simplest ketose dihydroxyacetone, has been observed in gas phase sources. A preliminary search for isomeric forms first targets ethoxy formic acid (C2H5-O-COOH) as the most stable isomer followed by lactic acid. Profiles corresponding to the minimum energy pathways reveal that the favored conformers of 14 of these isomers can be formed in the gas phase through 29 barrierless processes involving the OH∗, CH3O∗, HCO∗, CH3∗, CH2OH, HCOO∗, and OHCO∗ radicals, all of them observed in the interstellar medium. Kinetic rates are provided at 200, 298, and 500 K, confirming the suitability of 16 processes at low temperatures. Faster processes involve the OH hydroxyl radical whereas, to a lesser degree, the processes involving the HOCO radical and the methoxy methyl radical CH3O∗, are quite significant. Spectroscopic parameters (rovibrational and torsional) are obtained for methoxy acetic acid (CH3-O-CH2COOH) for which two low-lying isoenergetic conformers can be produced from the CH3OCH2∗ radical predicted to be a precursor of abundant observed molecules. Profiles and spectroscopic properties make methoxy acetic acid a good candidate to be detected in the gas phase of extraterrestrial sources., This project has received funding from the European Unionʼs Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 872081. This research was supported by the Ministerio de Ciencia, Innovación y Universidades of Spain through the grants EIN2019-103072 and FIS2016-76418-P. This work has received funding from the CSIC i-coop+2018 program under the reference number COOPB20364. V.G. acknowledges CONACyT (México) for the postdoctoral grants 2018-000022-01EXT-00386. The author acknowledges the CTI (CSIC) and CESGA and to the “Red Española de Computación” for the grants AECT-2020-2-0008 and RES-AECT2020-3-0011 for computing facilities.