JPLUS: Spectral evolution of white dwarfs by PDF analysis
Abstract
Aims: We estimated the spectral evolution of white dwarfs with effective temperature using the Javalambre Photometric Local Universe Survey (JPLUS) second data release (DR2), which provides 12 photometric optical passbands over 2176 deg^{2}.
Methods: We analyzed 5926 white dwarfs with r ≤ 19.5 mag in common between a white dwarf catalog defined from Gaia EDR3 and JPLUS DR2. We performed a Bayesian analysis by comparing the observed JPLUS photometry with theoretical models of hydrogen and heliumdominated atmospheres. We estimated the probability distribution functions for effective temperature (T_{eff}), surface gravity, parallax, and composition; and the probability of having a Hdominated atmosphere (p_{H}) for each source. We applied a prior in parallax, using Gaia EDR3 measurements as a reference, and derived a selfconsistent prior for the atmospheric composition as a function of T_{eff}.
Results: We described the fraction of white dwarfs with a Hedominated atmosphere (f_{He}) with a linear function of the effective temperature at 5000 < T_{eff} < 30 000 K. We find f_{He} = 0.24 ± 0.01 at T_{eff} = 10 000 K, a change rate along the cooling sequence of 0.14 ± 0.02 per 10 kK, and a minimum Hedominated fraction of 0.08 ± 0.02 at the hightemperature end. We tested the obtained p_{H} by comparison with spectroscopic classifications, finding that it is reliable. We estimated the mass distribution for the 351 sources with distance d < 100 pc, mass M > 0.45 M_{⊙}, and T_{eff} > 6000 K. The result for Hdominated white dwarfs agrees with previous studies, with a dominant M = 0.59 M_{⊙} peak and the presence of an excess at M ∼ 0.8 M_{⊙}. This highmass excess is absent in the Hedominated distribution, which presents a single peak.
Conclusions: The JPLUS optical data provide a reliable statistical classification of white dwarfs into H and Hedominated atmospheres. We find a 21 ± 3% increase in the fraction of Hedominated white dwarfs from T_{eff} = 20 000 K to T_{eff} = 5000 K.
The catalog with the atmospheric parameters and composition of the analyzed white dwarfs is available in electronic form both on the jplus.WhiteDwarf table at the JPLUS database and at the CDS via anonymous ftp to cdsarc.ustrasbg.fr (ftp://130.79.128.5) or via http://cdsarc.ustrasbg.fr/vizbin/cat/J/A+A/658/A79
 Publication:

Astronomy and Astrophysics
 Pub Date:
 February 2022
 DOI:
 10.1051/00046361/202141746
 arXiv:
 arXiv:2110.14421
 Bibcode:
 2022A&A...658A..79L
 Keywords:

 white dwarfs;
 methods: statistical;
 Astrophysics  Solar and Stellar Astrophysics
 EPrint:
 Published in Astronomy and Astrophysics. 18 pages, 15 figures, 4 tables