Dr. Christian Stephan Profile

Dr. Christian Stephan

at European Southern Observatory

SPIE Involvement:

Author

Publications (8)

Proceedings Article | 10 July 2018 Presentation + Paper

Technical operations and maintenance activities at the Paranal Observatory

M. Boccas, E. Diaz, M. Frantz, S. Gonzalez, G. Hüdepohl, I. Kastinen, V. Nurzia, P. Pozzobon, C. Ramirez, C. Reinero, F. Salgado, C. Stephan, J. Valenzuela

Proc. SPIE. 10704, Observatory Operations: Strategies, Processes, and Systems VII

KEYWORDS: Observatories, Telescopes, Reliability, Inspection, Efficient operations, Failure analysis

Read Abstract +

Proceedings Article | 10 July 2018 Paper

Framework to use modern big data software tools to improve operations at the Paranal Observatory

Eduardo Pena, Ricardo Schmutzer, Christian Stephan, Claudio Reinero, Julien Milli, Juan Guerra, Juan Osorio

Proc. SPIE. 10704, Observatory Operations: Strategies, Processes, and Systems VII

KEYWORDS: Human-machine interfaces, Observatories, Visualization, Data storage, Databases, Computing systems, Distributed computing, Machine learning, Software engineering, Atmospheric Cherenkov telescopes

Read Abstract +

Proceedings Article | 9 July 2018 Paper

MATISSE: performance in laboratory, results of AIV in Paranal, and first results on sky

S. Robbe-Dubois, S. Lagarde, P. Antonelli, B. Lopez, F. Allouche, C. Bailet, Ph. Berio, Y. Bresson, J.-M. Clausse, P. Cruzalèbes, Y. Fantei-Caujolle, A. Marcotto, A. Matter, A. Meilland, F. Millour, S. Morel, R. Petrov, S. Rousseau, A. Soulain, G. Zins, M. Lehmitz, W. Laun, T. Adler, R. Klein, T. Maurer, F. Bettonvil, E. Eldswick, U. Beckmann, M. Heininger, P. Bristow, A. Glindemann, N. Hubin, L. Jochum, Th. Rivinus, M. Schoeller, J. Beltran, P. Bourget, A. Gallenne, Th. Guerlet, X. Haubois, D. Ives, G. Jakob, A. Meister, M. Riquelme, N. Schuhler, C. Stephan, P. Toledo, K. Tristam, J. Woillez, U. Neumann, A. Chelli, F. Guitton, K. Meisenheimer, B. Pichon, A. Spang, J. Varga, Th. Henning, W. Jaffe, L. Pasquini, Ph. Stee, G. Weigelt

Proc. SPIE. 10701, Optical and Infrared Interferometry and Imaging VI

KEYWORDS: Photovoltaics, Telescopes, Spatial filters, Sensors, Calibration, Interferometry, L band, Spectral resolution, Astatine, Visibility

Read Abstract +

MATISSE (Multi AperTure mid-Infrared SpectroScopic Experiment) is the spectro-interferometer for the VLTI of the European Southern Observatory (ESO), operating in the L-, M- and N- spectral bands, and combining up to four beams from the unit or the auxiliary telescopes (UTs or ATs). MATISSE will offer new breakthroughs in the study of circumstellar environments by allowing the mapping of the material distribution, the gas and essentially the dust. The instrument consists in a warm optical system (WOP) accepting four beams from the VLTI and relaying them after a spectral splitting to cold optical benches (COB) located in two separate cryostats, one in L-M- band, and one in N-band. The test plan of the complete instrument has been conducted at the Observatoire de la Côte d’Azur in order to confirm the compliance of the performance with the high-level requirements. MATISSE has successfully passed the Preliminary Acceptance in Europe the 12th September 2017. Following this result, ESO gave approval for the instrument to be shipped to Paranal. The Alignment, Integration and Verification phase was conducted until end of February 2018, at the end of which first observations on sky have been performed to test the operations with the VLTI and to obtain first stellar light. The two first runs of the commissioning followed, respectively in March and in May 2018. It has the goal to optimize the MATISSE-VLTI communication, the acquisition procedures and the interface parameters. The observations were performed on bright L-M- and N- stars, with four ATs located on short baselines and UTs. The limit magnitudes will be deduced.

This paper reports on the performance of the instrument measured in laboratory (results of test plan in Nice and AIV in Paranal) in terms of spectral coverage, dispersion laws and spectral resolutions, and transfer function analysis: instrumental contrast, visibility accuracy, accuracy of the differential phase, of the closure-phase and of the differential visibility. It also provides results of the first tests on sky and the planning of the on-going commissioning.