The fountain of the luminous infrared galaxy Zw049.057 as traced by its OH megamaser
Artikel i vetenskaplig tidskrift, 2024
High-resolution (0″037-0″13 [10-35 pc]) e-MERLIN (λ6-18 cm) and (0″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″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″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″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.
Masers
Galaxies: ISM
Galaxies: kinematics and dynamics
Galaxies: nuclei
ISM: jets and outflows
Galaxies: evolution
Författare
Boy Lankhaar
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
Universiteit Leiden
Susanne Aalto
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
Clare Wethers
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
J. Moldon
Consejo Superior de Investigaciones Científicas (CSIC)
University of Manchester
R. J. Beswick
University of Manchester
Mark Gorski
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
Sabine König
Chalmers, Rymd-, geo- och miljövetenskap, Onsala rymdobservatorium
Chentao Yang
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
J. G. Mangum
National Radio Astronomy Observatory
J. S. Gallagher
Macalester College
University of Wisconsin
F. Combes
Observatoire de Paris
D. Rigopoulou
European University Cyprus
University of Oxford
E. Gonzalez-Alfonso
Universidad de Alcala
Sebastien Muller
Chalmers, Rymd-, geo- och miljövetenskap, Onsala rymdobservatorium
I. García-Bernete
University of Oxford
C. Henkel
Max-Planck-Gesellschaft
Y. Nishimura
University of Tokyo
C. Ricci
Universidad Diego Portales
Beijing University of Technology
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 689 A163Exploring the Hidden Dusty Nuclei of Galaxies (HIDDeN)
Europeiska forskningsrådet (ERC) (789410), 2018-10-01 -- 2023-09-30.
En polariserad syn på stjärnor, planeter och liv
Vetenskapsrådet (VR) (2021-00339), 2021-07-01 -- 2024-06-30.
Ämneskategorier (SSIF 2011)
Subatomär fysik
Astronomi, astrofysik och kosmologi
Atom- och molekylfysik och optik
DOI
10.1051/0004-6361/202450065