Loading…

Molecular hydrogen and [Fe ii] in active galactic nuclei — II. Results for Seyfert 2 galaxies

Near-infrared spectroscopy is used to study the kinematics and excitation mechanisms of H2 and [Fe ii] lines in a sample dominated by Seyfert 2 galaxies. The spectra simultaneously cover the JHK bands, allowing us to compare line fluxes emitted in the interval 0.8–2.4 μm and avoiding aperture and se...

Full description

Saved in:
Bibliographic Details
Published in:Monthly notices of the Royal Astronomical Society 2005-12, Vol.364 (3), p.1041-1053
Main Authors: Rodríguez-Ardila, A., Riffel, R., Pastoriza, M. G.
Format: Article
Language:English
Subjects:
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Near-infrared spectroscopy is used to study the kinematics and excitation mechanisms of H2 and [Fe ii] lines in a sample dominated by Seyfert 2 galaxies. The spectra simultaneously cover the JHK bands, allowing us to compare line fluxes emitted in the interval 0.8–2.4 μm and avoiding aperture and seeing effects. The H2 lines are systematically narrower than the narrow-line region lines, suggesting that, very likely, the H2 does not originate from the same parcel of gas that forms the narrow-line region. Emission-line ratios between H2 lines favour thermal excitation mechanisms for the molecular gas in active galactic nuclei. It was found that non-thermal excitation contributes, at most, 30 per cent of the observed H2. Thermal excitation is also confirmed by the rather similar vibrational and rotational temperatures in the objects (∼2000 K). The mass of hot H2 ranges from 102 to 103M⊙, with nearly half of objects showing values of
ISSN:0035-8711
1365-2966
DOI:10.1111/j.1365-2966.2005.09638.x