A population synthesis fitting of the Gaia resolved white dwarf binary population within 100 pc
| Autor: | S Torres, P Canals, F M Jiménez-Esteban, A Rebassa-Mansergas, E Solano |
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| Přispěvatelé: | Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. GAA - Grup d'Astronomia i Astrofísica, Ministerio de Economía y Competitividad (España), European Commission, Ministerio de Ciencia e Innovación (España) |
| Jazyk: | Catalan; Valencian |
| Rok vydání: | 2022 |
| Předmět: |
Galaxies--Evolution
Stars--Luminosity function FOS: Physical sciences Stars: luminosity function fundamental parameters [Stars] Stars - luminosity function Galaxies--Formation Binaries: general stellar content [Galaxy] luminosity function [Stars] Stars: fundamental parameters Solar and Stellar Astrophysics (astro-ph.SR) Galaxy: stellar content Binaries - general general [Binaries] White dwarfs Astronomy and Astrophysics Estels nans Astrophysics - Astrophysics of Galaxies Galàxies--Evolució Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science mass function Mass function Astrophysics of Galaxies (astro-ph.GA) Física::Astronomia i astrofísica [Àrees temàtiques de la UPC] Estels--Cúmuls Galaxy - stellar content White dwarf stars Stars - fundamental parameters |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | The $Gaia$ mission has provided an unprecedented wealth of information about the white dwarf population of our Galaxy. In particular, our studies show that the sample up to 100\,pc from the Sun can be considered as practically complete. This fact allows us to estimate a precise fraction of double-degenerate ($1.18\pm 0.10$\%) and white dwarf plus main-sequence stars ($6.31\pm0.23$\%) among all white dwarfs through comoving pairs identification. With the aid of a detailed population synthesis code we are able to reproduce synthetic white dwarf populations with nearly identical fractions as the observed ones, thus obtaining valuable information about the binary fraction, $f_{\rm b}$, initial mass ratio distribution, $n(q)$, and initial separation distribution, $f(a)$, among other parameters. Our best-fit model is achieved within a $1\sigma$ confidence level for $f(a)\propto a^{-1}$, $n(q)\propto q^{n_q}$, with $n_q=-1.13^{+0.12}_{-0.10}$ and $f_{\rm b}=0.32\pm 0.02$. The fraction of white dwarf mergers generated by this model is $9\sim16\%$, depending on the common-envelope treatment. As sub-products of our modelling we find that around $1\sim3\%$ of the white dwarf population are unresolved double-degenerates and that only $\sim1\%$ of all white dwarfs contain a He-core. Finally, only a mild kick during white dwarf formation seems to be necessary for fitting the observed sky separation of double-degenerate systems. Comment: 14 pages, 8 figures, 5 tables, accepted for publication in MNRAS |
| Databáze: | OpenAIRE |
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