Open AccessExcited molecular hydrogen around the Seyfert nuclei of NGC 3227 and 4151
Author(s) -
Fernandez B. R.,
Holloway A. J.,
Meaburn J.,
Pedlar A.,
Mundell C. G.
Publication year - 1999
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1999.02406.x
Subject(s) - physics , astrophysics , excited state , active galactic nucleus , galaxy , torus , nucleus , line (geometry) , galactic nuclei , telescope , astronomy , emission spectrum , hydrogen , atomic physics , spectral line , medicine , mathematics , psychiatry , quantum mechanics , geometry
High‐resolution images of the nuclear regions of the Seyfert galaxies NGC 3227 and 4151 have been obtained in the H 2 1‐0 S(1) emission line (rest λ = 2.1218 μ m) with the IRCAM3 camera on the 3.8‐m UKIRT telescope. A 2" elongation of the photoexcited H 2 is observed in NGC 3227 that is coincident with the optical nucleus. Combined with other observations, this indicates the presence of a molecular disc surrounding the active nucleus with the interior being photoexcited. A 2 × 2.5 arcsec 2 ring of excited H 2 centred on the nucleus is partially observed in NGC 4151. This is believed to be part of a circumnuclear torus that contains ionized, atomic and molecular gas in an onion‐skin structure.