Deciphering the imprint of active galactic nucleus feedback in Seyfert galaxies

Nuclear-scale molecular gas deficits

¹ Observatorio Astronómico Nacional (OAN-IGN)-Observatorio de Madrid, Alfonso XII, 3, 28014 Madrid, Spain
² Department of Physics & Astronomy, University of Alaska Anchorage, Anchorage, AK 99508-4664, USA
³ Department of Physics, University of Alaska, Fairbanks, AK 99775-5920, USA
⁴ Centro de Astrobiología (CAB), CSIC-INTA, Camino Bajo del Castillo s/n, 28692 Villanueva de la Cañada, Madrid, Spain
⁵ Instituto de Física Fundamental (IFF), CSIC, Serrano 123, 28006 Madrid, Spain
⁶ Instituto de Radioastronomía y Astrofísica (IRyA-UNAM), 3-72(Xangari), 8701 Morelia, Mexico
⁷ Instituto de Astrofísica de Canarias, Calle Vía Láctea, s/n, E-38205 La Laguna, Tenerife, Spain
⁸ Departamento de Astrofísica, Universidad de La Laguna, E-38205 La Laguna, Tenerife, Spain
⁹ LERMA, Observatoire de Paris, Collège de France, PSL University, CNRS, Sorbonne University, Paris, France
¹⁰ Department of Physics, University of Connecticut, 196 Auditorium Road, U-3046, Storrs, CT 06269-3046, USA
¹¹ Center for Computational Astrophysics, Flatiron Institute, 162 Fifth Avenue, New York, NY 10010, USA
¹² Departmento de Física de la Tierra y Astrofísica, Fac. de CC Físicas, Universidad Complutense de Madrid, E-28040 Madrid, Spain
¹³ Instituto de Física de Partículas y del Cosmos IPARCOS, Fac. de CC Físicas, Universidad Complutense de Madrid, E-28040 Madrid, Spain
¹⁴ Max-Planck-Institut für Extraterrestrische Physik, Garching, Germany
¹⁵ Cardiff Hub for Astrophysics Research & Technology, School of Physics & Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff CF24 3AA, UK
¹⁶ Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH, UK
¹⁷ School of Physics & Astronomy, University of Southampton, Hampshire, SO17 1BJ Southampton, UK
¹⁸ Telespazio UK for the European Space Agency (ESA), ESAC, Camino Bajo del Castillo s/n, 28692 Villanueva de la Cañada, Spain
¹⁹ The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA
²⁰ Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
²¹ Kavli Institute for Particle Astrophysics & Cosmology (KIPAC), Stanford University, Stanford, CA 94305, USA
²² National Astronomical Observatory of Japan, National Institutes of Natural Sciences (NINS), 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
²³ Instituto de Estudios Astrofísicos, Facultad de Ingeniería y Ciencias, Universidad Diego Portales, Av. Ejército Libertador 441, Santiago, Chile
²⁴ Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871, PR China
²⁵ School of Mathematics, Statistics and Physics, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
²⁶ Astronomical Observatory, Volgina 7, 11060 Belgrade, Serbia
²⁷ Sterrenkundig Observatorium, Universiteit Ghent, Krijgslaan 281-S9, Ghent B-9000, Belgium

Received: 5 April 2024
Accepted: 14 June 2024

Abstract

We study the distribution of cold molecular gas in the circumunuclear disks (CND; r ≤ 200 pc) of a sample of 64 nearby (D_L = 7 − 45 Mpc) disk galaxies – including 45 active galactic nuclei (AGN) and 19 nonAGN – for which high-spatial-resolution (median value ≃36 pc) multiline CO interferometer observations have been obtained at millimeter wavelengths with the Atacama Large Millimeter Array (ALMA) and/or Plateau de Bure Interferometer (PdBI). We decipher whether or not the concentration and normalized radial distribution of cold molecular gas change as a function of X-ray luminosity in the 2–10 keV range (L_X) in order to analyze the imprint left by AGN feedback. We also look for similar trends in the concentration and normalized radial distribution of the hot molecular gas and in the hot-to-cold-molecular gas mass ratio in a subset of 35 galaxies using near-infrared (NIR) integral field spectroscopy data obtained for the H₂ 1-0 S(1) line. We find a significant turnover in the distribution of the cold molecular gas concentration as a function of X-ray luminosity with a breakpoint that divides the sample into two branches: (1) the “AGN build-up branch” (L_X ≤ 10^{41.5 ± 0.3} erg s⁻¹) and (2) the “AGN feedback branch” (L_X ≥ 10^{41.5 ± 0.3} erg s⁻¹). Lower-luminosity AGN and nonAGN of the AGN build-up branch show high cold molecular gas concentrations and centrally peaked radial profiles on nuclear (r ≤ 50 pc) scales. Higher-luminosity AGN of the AGN feedback branch show a sharp decrease in the concentration of molecular gas and flat or inverted radial profiles. The cold molecular gas concentration index (CCI) – defined as the ratio of surface densities at r ≤ 50 pc (Σ₅₀^gaz) and r ≤ 200 pc Σ₂₀₀^gaz), namely CCI ≡ log₁₀(Σ₅₀^gaz/Σ₂₀₀^gaz)) – spans a 0.63 dex range, equivalent to a factor ≃4–5, between the galaxies lying at the high end of the AGN build-up branch and the galaxies showing the most extreme nuclear-scale molecular gas deficits in the AGN feedback branch. The concentration and radial distributions of the hot molecular gas in our sample follow qualitatively similar but less extreme trends as a function of X-ray luminosity. As a result, we find higher values of hot-to-cold molecular gas mass ratios on nuclear scales in the highest luminosity AGN sources of the AGN feedback branch. These observations confirm – with a three times larger sample – previous evidence found in the context of the Galaxy Activity Torus and Outflow Survey (GATOS) that the imprint of AGN feedback on the CND-scale distribution of molecular gas is more extreme in higher luminosity Seyfert galaxies of the local Universe.