Nicole Allard

Astronome

Observatoire de Paris
61, Avenue de l'Observatoire
75014 Paris
Téléphone : +33 1 45 43 35 74
Fax : +33 1 40 51 22 32
Email : nicole . allard à obspm . fr
Liste des publications 2014-* Liste complète des publications Alkali tables Lyman tables Earthy alkaline tables

Equipe : Physique stellaire et galactique

Travaux :

Etude théorique des profils de raies atomiques perturbées par collisions

Applications :

Naines blanches, naines brunes et planetes extrasolaires
Etoiles vieilles de la Branche Horizontale
Etoiles particulières de Population 1 de type lamboo

Research Interest :

Theory of spectral line profiles, with emphasis on neutral perturbers, mainly in all problems related to satellite line formation.
Collaboration since many years with John Kielkopf (U.S.A.) to the interpretation of laboratory data.
These calculations are of great theoretical interest in atomic physics, but have also important applications in astronomy.
  1. The fruitful convergence of several lines of research has allowed us to explain unexpected features in the ultraviolet spectra
    of DA White Dwarfs and peculiar A stars (metal-deficient A stars : Lamboo stars, metal-poor horizontal branch stars).
    This has led to several collaborations with astronomers, and the involvement in optical (ESO) as well as space-based (IUE, HST, FUSE) observations.
    Theoretical calculation of Lyman alpha, Lyman beta and Lyman gamma line profiles perturbed by neutral hydrogen and protons have been done in a large range of temperatures.

    T-dependent tables have been built to be implemented into TLUSTY and SYNSPEC, the atmosphere model and synthetic spectra codes of I. Hubeny and T. Lanz.

  2. Absorption profiles of alkali perturbed by high densities of helium and molecular hydrogen for the construction of models atmospheres and synthetic spectra for cool Brown Dwarfs and Extrasolar Giant Planets.

    3. T-dependent tables have been built to be implemented into PHOENIX