Improving white dwarfs as chronometers with gaia parallaxes and spectroscopic metallicities
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
White dwarfs (WDs) offer unrealized potential in solving two problems in astrophysics: stellar age accuracy and precision. WD cooling ages can be inferred from surface temperatures and radii, which can be constrained with precision by high-quality photometry and parallaxes. Accurate and precise Gaia parallaxes along with photometric surveys provide information to derive cooling and total ages for vast numbers of WDs. Here we analyze 1372 WDs found in wide binaries with main-sequence (MS) companions and report on the cooling and total age precision attainable in these WD+MS systems. The total age of a WD can be further constrained if its original metallicity is known because the MS lifetime depends on metallicity at fixed mass, yet metallicity is unavailable via spectroscopy of the WD. We show that incorporating spectroscopic metallicity constraints from 38 wide binary MS companions substantially decreases internal uncertainties in WD total ages compared to a uniform constraint. Averaged over the 38 stars in our sample, the total (internal) age uncertainty improves from 21.04% to 16.77% when incorporating the spectroscopic constraint. Higher mass WDs yield better total age precision; for eight WDs with zero-age MS masses ≥2.0 M⊙, the mean uncertainty in total ages improves from 8.61% to 4.54% when incorporating spectroscopic metallicities. We find that it is often possible to achieve 5% total age precision for WDs with progenitor masses above 2.0 M⊙ if parallaxes with ≤1% precision and Pan-STARRS g, r, and i photometry with ≤0.01 mag precision are available.
Date Issued
2022-04-01
Date Acceptance
2022-03-04
Citation
The Astrophysical Journal, 2022, 929 (1), pp.26-26
ISSN
0004-637X
Publisher
American Astronomical Society
Start Page
26
End Page
26
Journal / Book Title
The Astrophysical Journal
Volume
929
Issue
1
Copyright Statement
© 2022. The Author(s). Published by the American Astronomical Society.
License URL
Sponsor
Commission of the European Communities
Identifier
https://iopscience.iop.org/article/10.3847/1538-4357/ac5ac0
Grant Number
873089
Subjects
Astronomy & Astrophysics
0201 Astronomical and Space Sciences
0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics
0306 Physical Chemistry (incl. Structural)
Publication Status
Published
Date Publish Online
2022-04-11