August 11-15, 2014

Abstract

The white dwarf luminosity, mass and age functions as revealed by the LAMOST survey of the Galactic Anti-Center.

Alberto Rebassa-Mansergas (KIAA, Peking University)

Xiaowei Liu (Peking University), Ruxandra Cojocaru (UPC), Enrique Garcia-Berro (UPC), Santiago Torres (UPC), Haibo Yuan (Peking University)

The white dwarf population observed by a given survey can be used to determine white dwarf space densities, which allows to obtain the white dwarf luminosity function (LF), mass function (MF) and age function (AF). This exercise has been applied in the past to several different surveys. However, the white dwarf samples from which the currently observed LF, MF and AF are built are the result of complicated target selection algorithms and it becomes impossible e.g. to derive accurate white dwarf formation rates. The LAMOST survey of the Galactic Anti-Center (GAC) follows a well-defined selection criteria aiming at providing spectra for all stellar sources in the GAC (including white dwarfs) so that they can be studied in a statistically meaningful way. This has a significant advantage over previous surveys because we can apply this well-defined selection criteria to a simulated white dwarf population and directly compare the resulting LF, MF and AF to the observed ones. This exercise is crucial to evaluate the completeness of the observed sample and to thus obtain true white dwarf space densities and formation rates. In this contribution I present and describe in detail the white dwarf LF, MF and AF as derived from the LAMOST survey of the GAC.

Mode of presentation: oral