Structure, colours, and populations of NGC 3115. Mysteries of a well-known object

Autor: R. Michard
Přispěvatelé: Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS)
Jazyk: angličtina
Rok vydání: 2007
Předmět:
Zdroj: Astronomy and Astrophysics-A&A
Astronomy and Astrophysics-A&A, 2007, 464, pp.507-516. ⟨10.1051/0004-6361:20066358⟩
ISSN: 0004-6361
DOI: 10.1051/0004-6361:20066358⟩
Popis: International audience; Visible and near IR colour distributions in NGC 3115 have been studied from a set of frames of the Las Campanas Observatory and the 2MASS Atlas, plus other material from CFHT and OHP. The extended outer wings of the PSF were measured and their effect on such features as axis-ratio and colours carefully checked. In our data, the red-halo CCD phenomenon is the unique cause of a bluer major-axis in V-I. Morphological indices suggest that the disk of NGC 3115 was once a complete little spiral, before being "swallowed" by a much bigger object. All colour distributions show the major-axis slightly redder than the minor-axis regions, at least not far from centre, in the radial range where the disk stands out. This is interpreted in the framework of a bulge+disk model as a metallicity effect, the disk having locally a larger [Fe/H] by some 0.16 ± 0.04.
Databáze: OpenAIRE