The population of white dwarf-main sequence binaries in the SDSS DR 12

We present a Monte Carlo population synthesis study of white dwarf-main sequence (WD+MS) binaries in the Galactic disc aimed at reproducing the ensemble properties of the entire population observed by the Sloan Digital Sky Survey (SDSS) Data Release 12. Our simulations take into account all known ob...

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Bibliographic Details
Authors: Cojocaru, Elena Ruxandra|||0000-0003-0496-5355, Rebassa Mansergas, Alberto|||0000-0002-6153-7173, Torres Gil, Santiago|||0000-0001-5777-5251, García-Berro Montilla, Enrique|||0000-0002-1623-5838
Format: article
Publication Date:2017
Country:España
Institution:Universitat Politècnica de Catalunya (UPC)
Repository:UPCommons. Portal del coneixement obert de la UPC
Language:English
OAI Identifier:oai:upcommons.upc.edu:2117/107977
Online Access:https://hdl.handle.net/2117/107977
https://dx.doi.org/10.1093/mnras/stx1326
Access Level:Open access
Keyword:White dwarf stars
Astrophysics
Binaries: close
Binaries: spectroscopic
White dwarfs.
Estels nans
Astrofísica
Àrees temàtiques de la UPC::Física::Astronomia i astrofísica
Description
Summary:We present a Monte Carlo population synthesis study of white dwarf-main sequence (WD+MS) binaries in the Galactic disc aimed at reproducing the ensemble properties of the entire population observed by the Sloan Digital Sky Survey (SDSS) Data Release 12. Our simulations take into account all known observational biases and use the most up-to-date stellar evolutionary models. This allows us to perform a sound comparison between the simulations and the observational data. We find that the properties of the simulated and observed parameter distributions agree best when assuming low values of the common envelope efficiency (0.2-0.3), a result that is in agreement with previous findings obtained by observational and population synthesis studies of close SDSSWD+MS binaries.We also show that all synthetic populations that result from adopting an initial mass ratio distribution with a positive slope are excluded by observations. Finally, we confirm that the properties of the simulated WD+MS binary populations are nearly independent of the age adopted for the thin disc, on the contribution of WD+MS binaries from the thick disc (0-17 per cent of the total population) and on the assumed fraction of the internal energy that is used to eject the envelope during the common envelope phase (0.1-0.5).