Updated Evolutionary Sequences for Hydrogen-deficient White Dwarfs

CAMISASSA, M. E.; ALTHAUS, L. G.; R. D. ROHRMANN; E. GARCÍA-BERRO; S. TORRES; A. H. CÓRSICO; WACHLIN, F.

ASTROPHYSICAL JOURNAL

IOP PUBLISHING LTD

Lugar: Londres; Año: 2017 vol. 839

0004-637X

We present a set of full evolutionary sequences for white dwarfs withhydrogen-deficient atmospheres. We take into account the evolutionaryhistory of the progenitor stars, all the relevant energy sourcesinvolved in the cooling, element diffusion in the very outer layers, andouter boundary conditions provided by new and detailed non-gray whitedwarf model atmospheres for pure helium composition. These modelatmospheres are based on the most up-to-date physical inputs. Ourcalculations extend down to very low effective temperatures, of?2500 K, provide a homogeneous set of evolutionary cooling tracksthat are appropriate for mass and age determinations of oldhydrogen-deficient white dwarfs, and represent a clear improvement overprevious efforts, which were computed using gray atmospheres.