Lyon Data center for the Sciences of the Universe: LyDU
The LyDU hosts and develops services to exploit the spectroscopic resources in Astronomy.
They are essential tools for an optimal scientific usage of the vast corpus of astronomical data produced
by the modern telescopes and by the numerical simulations.
The PHOENIX simulator and archive
PHOENIX archive of spectra
contains collections of spectra
computed under a variety of physical hypotheses and conditions for a wide range of parameters, from the hottest stars to giant planets.
Together with the spectra, the atmosphere structures and the synthetic colours are available.
In the mid term, the spectra will also be available through the
The web interface provides added values services to evaluate the data, and transform them on-the-fly to suit special requirements.
Beside this interface, the spectra can also be accessed from the Virtual Observatory.
The LySI spectrum interpolator
LySI spectrum interpolator
is a service providing interpolated spectra based on empirical stellar libraries.
It is instrumental to the elaboration of stellar population models (for example with PEGASE) and
to the determination of the atmospheric parameters of stars.
LySI has been one of the first service in the Virtual Observatory delivering
, the University of Lyon Spectroscopic Software, is an analysis tools.
It is intended to perform a full-spectrum fitting of an observation against any kind of models.
It is essentially used to characterize the atmosphere of stars,
and to study the history of the star formation and metal enhancement in galaxies.
It takes advantage of LySI and of the Phoenix spectra.
The Virtual Observatory
The Virtual Observatory is a global effort shared by the astronomical community to facilitate the exchange of data among the astronomers. It develops the tools and standards needed to achieve the interoperability of the many services offered by institutions around the world.
LyDU services adopt those standards
and are interoperable with all the other services of the Virtual observatory.