Near-infrared interferometry of η Carinae with spectral resolutions of 1 500 and 12 000 using AMBER/VLTI

G. Weigelt, S. Kraus, T. Driebe, R. G. Petrov, K.-H. Hofmann, F. Millour, O. Chesneau, D. Schertl, F. Malbet, D. J. Hillier, T. Gull, M. Davidson, A. Domiciano de Sousa Jr., P. Antonelli, U. Beckmann, Y. Bresson, A. Chelli, G. Duvert, S. Gennari, P. Kern, S. Lagarde, E. Le Coarer, F. Lisi, K. Perraut, P. Puget, S. Robbe-Dubois, A. Roussel, E. Tatulli, G. Zins, M. Accardo, B. Acke, K. Agabi, E. Altariba, B. Arezki, E. Aristidi, C. Baffa, J. Behrend, S. Bonhomme, S. Busoni, F. Cassaing, J.-M. Clausse, J. Colin, C. Connot, P. Feautrier, D. Ferruzzi, T. Forveille, E. Fossat, R. Foy, D. Fraix-Burnet, A. Gallardo, E. Giani, C. Gil, A. Glentzlin, M. Heiden, M. Heininger, O. Hernandez, D. Kamm, M. Kiekebusch, D. Le Contel, J.-M Le Contel, T. Lesourd, B. Lopez, M. Lopez, Y. Magnard, A. Marconi, G. Mars, G. Martinot-Lagarde, P. Mathias, J.-L. Monin, D. Mouillet, D. Mourard, E. Nussbaum, K. Ohnaka, J. Pacheco, C. Perrier, Y. D. Rabbia, S. Rebattu, F. Reynaud, A. Richichi, A. Robini, M. Sacchettini, W. Solscheid, A. Spang, P. Stee, P. Stefanini, M. Tallon, I. Tallon-Bosc, D. Tasso, L. Testi, F. Vakili, J.-C. Valtier, M. Vannier, N. Ventura, K. Weis, M. Wittkowski

Abstract
Aims. We present the first NIR spectro-interferometry of the LBV η Carinae. The observations were performed with the AMBER instrument of the ESO Very Large Telescope Interferometer (VLTI) using baselines from 42 to 89 m. The aim of this work is to study the wavelength dependence of η Car’s optically thick wind region with a high spatial resolution of 5 mas (11 AU) and high spectral resolution.
Methods. The observations were carried out with three 8.2 m Unit Telescopes in the K-band. The raw data are spectrally dispersed interferograms obtained with spectral resolutions of 1500 (MR-K mode) and 12 000 (HR-K mode). The MR-K observations were performed in the wavelength range around both the He i 2.059 μm and the Brγ 2.166 μm emission lines, the HR-K observations only in the Brγ line region.
Methods. The observations were carried out with three 8.2 m Unit Telescopes in the K-band. The raw data are spectrally dispersed interferograms obtained with spectral resolutions of 1500 (MR-K mode) and 12 000 (HR-K mode). The MR-K observations were performed in the wavelength range around both the He i 2.059 μm and the Brγ 2.166 μm emission lines, the HR-K observations only in the Brγ line region.

Astronomy and Astrophysics
Volume 464, Page 87
February 2007

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