Year: 2024
Type: article
Abstract: High-resolution ($ 0{{\overset{\prime\prime}{.}}}037{-}0{{\overset{\prime\prime}{.}}}13 $ [10 − 35 pc]) e-MERLIN (λ6 − 18 cm) and ($ 0{{\overset{\prime\prime}{.}}}024 $ [6.5 pc]) ALMA (λ1.1 mm) observations have been used to image OH (hydroxyl) and H2CO (formaldehyde) megamaser emission, and HCN 3 → 2 emission toward the nuclear (< 100 pc) region of the luminous infrared galaxy Zw049.057. Zw049.057 hosts a compact obscured nucleus (CON), and thus represents a class of galaxies that are often associated with inflow and outflow motions. Formaldehyde megamaser emission has been detected toward the nuclear region, ≲30 pc ($ 0{{\overset{\prime\prime}{.}}}1 $), and traces a structure along the disk major axis. OH megamaser (OHM) emission has been detected along the minor axis of the disk, ∼30 pc ($ 0{{\overset{\prime\prime}{.}}}1 $) from the nucleus, where it exhibits a velocity gradient with extrema of −20 km s−1 southeast (SE) of the disk and −110 km s−1 northwest (NW) of the disk. HCN 3 → 2 emission reveals extended emission, along the disk minor axis out to ∼60 pc ($ 0{{\overset{\prime\prime}{.}}}2 $). Analysis of the minor axis HCN emission reveals high-velocity features extending out to 600 km s−1, redshifted on the SE side and blueshifted on the NW side. We propose that the high-velocity HCN emission traces a fast (> 250 km s−1) and collimated outflow that is enveloped by a wide-angle and slow (∼50 km s−1) outflow that is traced by the OHM emission. Analysis of the outflow kinematics suggests that the slow wide-angle outflow will not reach escape velocity and will instead fall back to the galaxy disk, evolving as a so-called fountain flow, while the fast collimated outflow traced by HCN emission will likely escape the nuclear region. We suggest that the absence of OHM emission in the nuclear region is due to high densities there. Even though OHMs associated with outflows are an exception to conventional OHM emission, we expect them to be common in CON sources that host both OHM and H2CO megamasers.
Authors: Boy Lankhaar, Susanne Aalto, Clare Wethers, Javier Moldon, Rob Beswick, Mark Gorski, Sabine König, Chentao Yang, Jeff Mangum, John Gallagher, Françoise Combes, Dimitra Rigopoulou, Eduardo González-Alfonso, Sébastien Muller, Ismael Garcia-Bernete, Christian Henkel, Yuri Nishimura, Claudio Ricci
Institutions: Leiden University, Leiden Observatory, Chalmers University of Technology, University of Manchester, Instituto de Astrofísica de Andalucía, National Radio Astronomy Observatory, Macalester College, Centre National de la Recherche Scientifique, Collège de France, Université Paris Sciences et Lettres, Observatoire de Paris, Sorbonne Université, Laboratoire d’Etudes du Rayonnement et de la Matière en Astrophysique et Atmosphères, European University Cyprus, University of Oxford, Universidad de Alcalá, Max Planck Institute for Radio Astronomy, The University of Tokyo, Peking University, Universidad Diego Portales
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, Ministerio de Ciencia, Innovación y Universidades, National Radio Astronomy Observatory, Korea Astronomy and Space Science Institute, Vetenskapsrådet, National Astronomical Observatory of Japan, Agencia Nacional de Investigación y Desarrollo, National Institutes of Natural Sciences, European Regional Development Fund, Agencia Estatal de Investigación, H2020 European Research Council
Awards: HIDDeN - Exploring the Hidden Dusty Nuclei of Galaxies, EXTREME SUPERMASSIVE BLACK HOLE ACCRETION, G3480869486, G373897614, G3780957795, G3817602061, G4426983848, G463062595, G5834573078, G5894067328, A polarized view on stars, planets and life, G7084143925, The Many Facets of Sustainable Development, CENTRO DE ASTROFISICA Y TECNOLOGIAS AFINES (CATA)
OpenAlex ID: W6959639485
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