A homogeneous set of ESPaDOnS/CFHT and NARVAL/TBL spectra
All ESPaDOnS/CFHT and NARVAL/TBL spectra collected during allocated runs will be
reprocessed in a homogeneous way with Libre_ESpRIT, the dedicated spectropolarimetric
reduction package especially designed for ESPaDOnS and NARVAL data. Spectra are
reduced using Optimal Extraction as devised by Horne & Marsh and include error bar
estimates at all wavelength pixels.
The collected reduced spectra will feed a database, to be accessible by the entire
astrophysical community. This database is expected to be very useful for most
studies in stellar & solar physics, just as databases of synthetic spectra or atmospheric
models are nowadays; it should also be very useful to investigate a posteriori, eg
secular changes in the properties of stars of given stellar classes.
This database should also provide a new source of reliable information to other domains
of astrophysics, like for instance atomic physics (eg to investigate the formation
and properties of molecular lines) or galactic physics (eg to study stellar
populations from high resolution composite spectra of galaxies). This database
thus clearly features a LEGACY dimension; as for the HST database, we expect that
it will also further increase the impact of spectropolarimetric data and associated
instruments in terms of refereed publications and citations.
Automatic spectral classification
We are building up an Automatic Spectral Classification tool based on the MATISSE
(Recio-Blanco et al, 2006, MNRAS 370, 141) algorithm (sharing similarities with
Principal Component Analysis). Ultimately, this tool should yield accurate stellar
atmospheric parameters for all reduced ESPaDOnS/NARVAL spectra, from a comparison
to both synthetic spectra (POLLUX data base) and observed reference stellar spectra
(collected with ESPaDOnS and NARVAL).
The complete data base
The complete data base will include each observed spectrum, the corresponding Least-Squares
Deconvolution (LSD, Donati et al 1997, MNRAS 291, 658) profile and all relevant
characteristics derived either from LSD profiles (rotation and radial
velocity, binary, magnetic field detection), from the automatic spectral classification
tool (effective temperature, logarithmic gravity, metallicity, veiling), from
comparisons to stellar evolution models (mass, radius, age) and from comparisons of
multiple exposures (variability).
The data base will be accessible to the whole astronomical community and will feature
links to the SIMBAD and POLLUX databases. The first version of this database should be
operational in 2008/2009 - it will then be regularly updated, with new spectra brought
online as soon as they enter public domain.
Possible extensions to other spectropolarimetric data sets (eg FORS1, MuSiCoS) are
Core team and collaborators
Thread coordinator: P Petit, A Lèbre, S Bagnulo, D Bohlender