An asteroseismic constraint on the mass of the axion from the period drift of the pulsating DA white dwarf star L19-2

CÓRSICO, A. H.; ROMERO, A. D.; ALTHAUS, L. G.; GARCÍA-BERRO, E.; ISERN, J.; KEPLER, S. O.; MILLER BERTOLAMI, M. M.; SULLIVAN, D. J.; CHOTE, P.

JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS

IOP PUBLISHING LTD

Lugar: Londres; Año: 2016

1475-7516

We employ an asteroseismic model of L19-2, a relatively massive(Mstar ~ 0.75 Msolar) and hot (Teff ~12 100 K) pulsating DA (H-rich atmosphere) white dwarf star (DAV or ZZCeti variable), and use the observed values of the temporal rates ofperiod change of its dominant pulsation modes (Π ~ 113 s and Π ~192 s), to derive a new constraint on the mass of the axion, thehypothetical non-barionic particle considered as a possible component ofthe dark matter of the Universe. If the asteroseismic model employed isan accurate representation of L19-2, then our results indicate hints ofextra cooling in this star, compatible with emission of axions of massma cos2β lesssim 25 meV or an axion-electroncoupling constant of gae lesssim 7 ×10‑13.