Discovery of methanimine (CH2NH) megamasers toward compact obscured galaxy nuclei
Journal article, 2021

We present the first search for the 5.29 GHz methanimine (CH2NH) 110 - 111 transition toward a sample of galaxy nuclei. We target seven galaxies that host compact obscured nuclei (CONs) with the Karl G. Jansky Very Large Array. These galaxies are characterized by Compton-thick cores. CH2NH emission is detected toward six CONs. The brightness temperatures measured toward Arp 220 indicate maser emission. Isotropic luminosities of the CH2NH transition, from all sources where it is detected, exceed 1 Lpdbl and thus may be considered megamasers. We also detect formaldehyde (H2CO) emission toward three CONs. The isotropic CH2NH luminosities are weakly correlated with the infrared luminosity of the host galaxy and strongly correlated with OH megamaser luminosities from the same galaxies. Non-local thermodynamic equilibrium radiative transfer models suggest that the maser is pumped by the intense millimeter-to-submillimeter Our study suggests that CH2NH megamasers are linked to the nuclear processes within 100 pc of the Compton-thick nucleus within CONs.

Radio lines: galaxies

Galaxies: nuclei

Galaxies: ISM

Masers

Author

Mark Gorski

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics, Extragalactic Astrophysics

Susanne Aalto

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

J. G. Mangum

National Radio Astronomy Observatory

E. Momjian

National Radio Astronomy Observatory Socorro

John H Black

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics, Galactic Astrophysics

Niklas Falstad

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics, Extragalactic Astrophysics

Bitten Gullberg

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics, Extragalactic Astrophysics

Sabine König

Chalmers, Space, Earth and Environment, Onsala Space Observatory, Observation Support

Kyoko Onishi

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics, Extragalactic Astrophysics

Mamiko Sato

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics, Extragalactic Astrophysics

F. Stanley

Pierre and Marie Curie University (UPMC)

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 654 A110

Subject Categories

Subatomic Physics

Astronomy, Astrophysics and Cosmology

Atom and Molecular Physics and Optics

DOI

10.1051/0004-6361/202141633

More information

Latest update

11/8/2021