AGN X-Ray Irradiation of CO Gas in NGC 2110 Revealed by Chandra and ALMA
Journal article, 2020

We report spatial distributions of the Fe-K alpha line at 6.4 keV and the CO(J = 2-1) line at 230.538 GHz in NGC 2110, which are, respectively, revealed by Chandra and Atacama Large Millimeter/submillimeter Array (ALMA) at 05. A Chandra 6.2-6.5 keV to 3.0-6.0 keV image suggests that the Fe-K alpha emission extends preferentially in a northwest to southeast direction out to 3 '', or similar to 500 pc, on each side. Spatially resolved spectral analyses support this by finding significant Fe-K alpha emission lines only in the northwest and southeast regions. Moreover, their equivalent widths are found to be similar to 1.5 keV, indicative for the fluorescence by nuclear X-ray irradiation as the physical origin. By contrast, CO(J = 2-1) emission is weak therein. For quantitative discussion, we derive ionization parameters by following an X-ray dominated region (XDR) model. We then find them high enough to interpret the weakness as the result of X-ray dissociation of CO and/or H-2. Another possibility also remains that CO molecules follow a superthermal distribution, resulting in brighter emission in higher-J lines. Further follow-up observations are encouraged to draw a conclusion on what predominantly changes the interstellar matter properties and whether the X-ray irradiation eventually affects the surrounding star formation as active galactic nucleus (AGN) feedback.

Molecular gas

AGN host galaxies

Star formation

X-ray active galactic nuclei

Radio astronomy

Submillimeter astronomy

X-ray astronomy

Astrophysical black holes

Active galactic nuclei

Author

Taiki Kawamuro

National Astronomical Observatory of Japan

Takuma Izumi

National Astronomical Observatory of Japan

The Graduate University for Advanced Studies (SOKENDAI)

Kyoko Onishi

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

Masatoshi Imanishi

National Astronomical Observatory of Japan

The Graduate University for Advanced Studies (SOKENDAI)

Dieu D. Nguyen

National Astronomical Observatory of Japan

Shunsuke Baba

National Astronomical Observatory of Japan

Astrophysical Journal

0004-637X (ISSN) 1538-4357 (eISSN)

Vol. 895 2 135

Subject Categories

Meteorology and Atmospheric Sciences

Astronomy, Astrophysics and Cosmology

Atom and Molecular Physics and Optics

DOI

10.3847/1538-4357/ab8b62

More information

Latest update

7/1/2020 6