INVESTIGADORES
ROHRMANN Rene Daniel
artículos
Título:
New cooling sequences for old white dwarfs
Autor/es:
RENEDO, I.; ALTHAUS, L. G.; M. M. MILLER-BERTOLAMI; ROMERO, A. D.; CORSICO, A. H.; ROHRMANN, R. D.; GARCÍA-BERRO, E.
Revista:
ASTROPHYSICAL JOURNAL
Editorial:
IOP PUBLISHING LTD
Referencias:
Año: 2010 vol. 717 p. 183 - 195
ISSN:
0004-637X
Resumen:
We present full evolutionary calculations appropriate for the study of
hydrogen-rich DA white dwarfs. This is done by evolving white dwarf progenitors
from the zero age main sequence, through the core hydrogen burning phase, the
helium burning phase and the thermally pulsing asymptotic giant branch phase to
the white dwarf stage. Complete evolutionary sequences are computed for a wide
range of stellar masses and for two different metallicities: Z=0.01, which is
representative of the solar neighborhood, and Z=0.001, which is appropriate for
the study of old stellar systems, like globular clusters. During the white
dwarf cooling stage we compute self-consistently the phase in which nuclear
reactions are still important, the diffusive evolution of the elements in the
outer layers and, finally, we also take into account all the relevant energy
sources in the deep interior of the white dwarf, like the release of latent
heat and the release of gravitational energy due to carbon-oxygen phase
separation upon crystallization. We also provide colors and magnitudes for
these sequences, based on a new set of improved non-gray white dwarf model
atmospheres, which include the most up-to-date physical inputs like the Lyman
alpha quasi-molecular opacity. The calculations are extended down to an
effective temperature of 2,500 K. Our calculations provide a homogeneous set of
evolutionary cooling tracks appropriate for mass and age determinations of old
DA white dwarfs and for white dwarf cosmochronology of the different Galactic
populations.