Precise Ages of Field Stars From White Dwarf Companions in Gaia DR2

Autor: Qiu, Dan, Tian, Hai-Jun, Wang, Xi-Dong, Nie, Jia-Lu, von Hippel, Ted, Liu, Gao-Chao, Fouesneau, Morgan, Rix, Hans-Walter
Rok vydání: 2020
Předmět:
Druh dokumentu: Working Paper
DOI: 10.3847/1538-4365/abe468
Popis: We analyze 4\,050 wide binary star systems involving a white dwarf (WD) and usually a main sequence (MS) star, drawn from the large sample assembled by \citet[][hereafter, T20]{Tian_2020}. Using the modeling code BASE-9, we determine the system's ages, the WD progenitors' ZAMS masses, the extinction values ($A_V$), and the distance moduli. Discarding the cases with poor age convergences, we obtain ages for 3\,551 WDs, with a median age precision of $\sigma_{\tau}/\tau = 20$\%, and system ages typically in the range of 1-6 Gyr. We validated these ages against the very few known clusters and through cross-validation of 236 WD-WD binaries. Under the assumption that the components are co-eval in a binary system, this provides precise age constraints on the usually low-mass MS companions, mostly inaccessible by any other means.
Comment: 15 pages, 10 figures, 4 tables, accepted for publication in The Astrophysical Journal Supplement Series
Databáze: arXiv