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oai:recercat.cat:2117/1742602026-01-28T02:33:44Zcom_2072_1033col_2072_452950

urn:hdl:2117/174260 Random Forest identification of the thin disc, thick disc, and halo Gaia-DR2 white dwarf population Torres Gil, Santiago Cantero, C. Rebassa Mansergas, Alberto Skorobogatov, G. Jiménez Esteban, F. M. Solano Márquez, Enrique Àrees temàtiques de la UPC::Física::Astronomia i astrofísica White dwarf stars Stars--Luminosity function Stars--Masses Stars: white dwarfs Galaxy: stellar content Stars: luminosity function mass function Estels nans Galàxies -- Formació Gaia-DR2 has provided an unprecedented number of white dwarf candidates of ourGalaxy. In particular, it is estimated thatGaia-DR2 has observed nearly 400 000 ofthese objects and close to 18 000 up to 100 pc from the Sun. This large quantity ofdata requires a thorough analysis in order to uncover their main Galactic popula-tion properties, in particular the thin and thick disk and halo components. Takingadvantage of recent developments in artificial intelligence techniques, we make useof a detailed Random Forest algorithm to analyse an 8-dimensional space (equato-rial coordinates, parallax, proper motion components and photometric magnitudes)of accurate data provided byGaia-DR2 within 100 pc from the Sun. With the aid ofa thorough and robust population synthesis code we simulated the different compo-nents of the Galactic white dwarf population to optimize the information extractedfrom the algorithm for disentangling the different population components. The algo-rithm is first tested in a known simulated sample achieving an accuracyof 85.3%. Ourmethodology is thoroughly compared to standard methods based on kinematic criteriademonstrating that our algorithm substantially improves previous approaches. Oncetrained, the algorithm is then applied to theGaia-DR2 100 pc white dwarf sample,identifying 12 227 thin disk, 1410 thick disk and 95 halo white dwarf candidates, whichrepresent a proportion of 74:25:1, respectively. Hence, the numerical spatial densitiesare (3.6±0.4)×10-3pc-3, (1.2±0.4)×10-3pc-3and (4.8±0.4)×10-5pc-3forthe thin disk, thick disk and halo components, respectively. The populations thus ob-tained represent the most complete and volume-limited samples to date of the differentcomponents of the Galactic white dwarf population. Peer Reviewed Preprint 2019-03-13 Article This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society Published by Oxford University Press on behalf of the Royal Astronomical Society. https://academic.oup.com/mnras/article-abstract/485/4/5573/5398538 info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/AYA2017-86274-P/ES/DEL ENFRIAMIENTO A LAS EXPLOSIONES: LA FISICA DE LOS OBJETOS COMPACTOS/ info:eu-repo/grantAgreement/SPAIN/MINECO/RYC-2016-20254 info:eu-repo/grantAgreement/AGAUR/SGR-661/201 info:eu-repo/grantAgreement/EC/H2020/653477/EU/Astronomy ESFRI and Research Infrastructure Cluster/ASTERICS http://creativecommons.org/licenses/by-nc-nd/3.0/es/ Open Access Attribution-NonCommercial-NoDerivs 3.0 Spain Oxford University Press