AAS 203rd Meeting, January 2004
Session 32 Spiral Galaxies
Oral, Monday, January 5, 2004, 2:00-3:30pm, Centennial IV

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[32.04] A near-IR spectral atlas of nearby spiral galaxies: spectral signatures of nuclear activity?

T.G. Hawarden, L.S. Douglas, G.S. Wright (UK Astronomy Technology Centre, Royal Observatory, UK), M.Y. Takamiya (Deparment of Physics, University of Hawaii in Hilo), S.D. Ryder (Anglo-Australian Observatory)

A 1 - 2.48 \mum spectroscopic survey of 31 nearby IR-bright spiral galaxies shows several spectral signatures of various classes of nuclear or near-nuclear activity. A significant subgroup of Type 2 Seyfert systems (S2s) have NIR spectra dominated by H2 emission lines,probably from shocks, but in some cases without accompanying strong [FeII] 1.644/ 1.257 \mum features. The continua in many, but not all, galaxies classed as AGN in the optical rise strongly to the red in the H and K bands, filling in the strong stellar CO features. The [SiIV] \lambda 1.965 \mum line occurs in both Type 1 and Type 2 nuclei and is commonly accompanied by the [CaVIII] \lambda 2.321 \mum feature. An as-yet unidentified feature at 2.350 \mum may be present in two galaxies. Several starforming and AGN systems exhibit one or both of a pair of lines near 1.19 \mum, attributed to [PII] and [NiII]; the latter may be a tracer of SN activity, but systematics have yet to be discerned.

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Bulletin of the American Astronomical Society, 35#5
© 2003. The American Astronomical Soceity.