The Galaxy Activity, Torus, and Outflow Survey (GATOS)

I. ALMA images of dusty molecular tori in Seyfert galaxies

¹ Observatorio Astronómico Nacional (OAN-IGN)-Observatorio de Madrid, Alfonso XII, 3, 28014 Madrid, Spain
e-mail: s.gburillo@oan.es
² Centro de Astrobiología (CSIC-INTA), ESAC Campus, 28692 Villanueva de la Cañada, Madrid, Spain
³ Instituto de Astrofísica de Canarias, Calle Vía Láctea, s/n, 38205 La Laguna, Tenerife, Spain
⁴ Departamento de Astrofísica, Universidad de La Laguna, 38205 La Laguna, Tenerife, Spain
⁵ Instituto de Radioastronomía y Astrofísica (IRyA-UNAM), 3-72(Xangari), 8701 Morelia, Mexico
⁶ LERMA, Observatoire de Paris, Collège de France, PSL University, CNRS, Sorbonne University, Paris, France
⁷ Department of Physics & Astronomy, University of Southampton, Hampshire S17 1BJ, Southampton, UK
⁸ Department of Physics & Astronomy, University of Alaska Anchorage, Anchorage, AK 99508-4664, USA
⁹ INAF – Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, 50125 Firenze, Italy
¹⁰ Centre for Extragalactic Astronomy, Department of Physics, Durham University, South Road, Durham DH1 3LE, UK
¹¹ Max-Planck-Institut für Extraterrestrische Physik, Garching, Germany
¹² Astronomical Institute, Academy of Sciences, Boĉní II 1401, 14131 Prague, Czechia
¹³ Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX13RH, UK
¹⁴ Leiden Observatory, PO Box 9513 2300 RA Leiden, The Netherlands
¹⁵ Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir, 28850 Torrejón de Ardoz, Madrid, Spain
¹⁶ Institute of Astrophysics, Foundation for Research and Technology-Hellas, 71110 Heraklion, Greece
¹⁷ Astronomical Institute, Tohoku University 6-3 Aramaki, Aoba-ku, Sendai 980-8578, Japan
¹⁸ National Astronomical Observatory of Japan, National Institutes of Natural Sciences (NINS), 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
¹⁹ Department of Astronomy, School of Science, The Graduate University for Advanced Studies, SOKENDAI, Mitaka, Tokyo 181-8588, Japan
²⁰ Space Telescope Science Institute, Baltimore, MD 21218, USA
²¹ Kavli Institute for Particle Astrophysics & Cosmology (KIPAC), Stanford University, Stanford, CA 94305, USA
²² SOFIA Science Center, NASA Ames Research Center, Moffett Field, CA 94035, USA
²³ The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA
²⁴ Núcleo de Astronomía de la Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército Libertador 441, Santiago, Chile
²⁵ Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871, PR China
²⁶ LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, 5 place Jules Janssen, 92190 Meudon, France
²⁷ Astronomical Observatory, Volgina 7, 11060 Belgrade, Serbia
²⁸ Sterrenkundig Observatorium, Universiteit Ghent, Krijgslaan 281-S9, Ghent 9000, Belgium
²⁹ Kagoshima University, Graduate School of Science and Engineering, Kagoshima 890-0065, Japan
³⁰ Ehime University, Research Center for Space and Cosmic Evolution, Matsuyama 790-8577, Japan
³¹ Hokkaido University, Faculty of Science, Sapporo 060-0810, Japan

Received: 13 April 2021
Accepted: 22 June 2021

Abstract

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 active galactic nuclei (AGN) luminosities and Eddington ratios covered by previous surveys of Seyferts conducted by the Atacama Large Millimeter Array (ALMA), allowing 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 μm with high spatial resolutions (0.1″ ∼ 7 − 13 pc) in the circumnuclear disks (CND) of ten nearby (D < 28 Mpc) Seyfert galaxies selected from an ultra-hard X-ray survey. Our new ALMA observations detect 870 μm continuum and CO line emission from spatially resolved disks located around the AGN in all the sources. The bulk of the 870 μm 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 × 10⁵ M_⊙, respectively. We also detected the emission of the 4–3 line of HCO⁺ in four GATOS targets. The order of magnitude differences found in the CO/HCO⁺ ratios within our combined sample point to a very different density radial stratification inside the dusty molecular tori of these Seyferts. 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 toward the AGN in our sources. Furthermore, the median values of both column densities are similar. This suggests that the neutral gas line-of-sight column densities of the dusty molecular tori imaged by ALMA significantly contribute to the obscuration of X-rays. 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.