Excited molecular hydrogen around the Seyfert nuclei of NGC 3227 and 4151

Citation
Br. Fernandez et al., Excited molecular hydrogen around the Seyfert nuclei of NGC 3227 and 4151, M NOT R AST, 305(2), 1999, pp. 319-324
Citations number
30
Categorie Soggetti
Space Sciences
Journal title
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
ISSN journal
00358711 → ACNP
Volume
305
Issue
2
Year of publication
1999
Pages
319 - 324
Database
ISI
SICI code
0035-8711(19990511)305:2<319:EMHATS>2.0.ZU;2-V
Abstract
High-resolution images of the nuclear regions of the Seyfert galaxies NGC 3 227 and 4151 have been obtained in the H-2 1-0 S(1) emission line (rest lam bda = 2.1218 mu m) with the IRCAM3 camera on the 3.8-m UKIRT telescope. A 2 arcsec 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 x 2.5 arcsec(2) ring of excited H -2 centred on the nucleus is partially observed in NGC 4151. This is believ ed to be part of a circumnuclear torus that contains ionized, atomic and mo lecular gas in an onion-skin structure.