Instituut voor Sterrenkunde, K.U.Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium
2 SRON National Institute for Space Research, Groningen, The Netherlands
3 Max-Planck-Institut für Extraterrestrische Physik, Garching, Germany
4 Astrophysics Missions Division, Research and Scientific Support Department of ESA, ESTEC, PO Box 299, 2200 AG Noordwijk, The Netherlands
5 Sterrenkundig Instituut “Anton Pannekoek”, Amsterdam, The Netherlands
6 ISO Data Center, Astrophysics Division of ESA, Villafranca del Castillo, Spain
Corresponding author: B. Vandenbussche, Bart.Vandenbussche@ster.kuleuven.ac.be
Accepted: 15 May 2002
We present an atlas of near-infrared spectra (2.36 μm–4.1 μm) of ~300 stars at moderate resolution (λ/–2000). The spectra were recorded using the Short-Wavelength Spectrometer aboard the Infrared Space Observatory (ISO-SWS). The bulk of the observations were performed during a dedicated observation campaign after the liquid helium depletion of the ISO satellite, the so-called post-helium programme. This programme was aimed at extending the MK-classification to the near-infrared. Therefore the programme covers a large range of spectral types and luminosity classes. The 2.36 μm–4.05 μm region is a valuable spectral probe for both hot and cool stars. H I lines (Bracket, Pfund and Humphreys series), He I and He II lines, atomic lines and molecular lines (CO, H2O, NH, OH, SiO, HCN, C2H2, ...) are sensitive to temperature, gravity and/or the nature of the outer layers of the stellar atmosphere (outflows, hot circumstellar discs, etc.). Another objective of the programme was to construct a homogeneous dataset of near-infrared stellar spectra that can be used for population synthesis studies of galaxies. At near-infrared wavelengths these objects emit the integrated light of all stars in the system. In this paper we present the dataset of post-helium spectra completed with observations obtained during the nominal operations of the ISO-SWS. We discuss the calibration of the SWS data obtained after the liquid helium boil-off and the data reduction. We also give a first qualitative overview of how the spectral features in this wavelength range change with spectral type. The dataset is scrutinised in two papers on the quantitative classification of near-infrared spectra of early-type stars (Lenorzer et al. [CITE]) and late-type stars (Vandenbussche et al., in prep).
Key words: stars: general / infrared: stars / atlases
Based on observations with ISO, an ESA project with instruments funded by ESA Members States (especially the PI countries France, Germany, the Netherlands and the United Kingdom) and with the participation of ISAS and NASA.
© ESO, 2002