Program: GN-2011A-Q-98

Title:Confirming and Characterizing Cool and Old White Dwarfs Found in the UKIRT Infrared Sky Survey
PI:Sandy Leggett
Co-I(s): Pierre Bergeron, Nicolas Lodieu, Atsuko Nitta, Pier-Emmanuel Tremblay

Abstract

White dwarfs are the end-point of evolution for the majority of stars. These degenerate remnants cool in a well-understood way and the coolest constrain the age of the Disk, or even older Galaxy components if they can be found. ~20 white dwarfs are known with effective temperatures <~4000K and ages 8-12Gyr. We are searching for similar dwarfs using the UKIDSS and SDSS databases, through color and proper motion selections. Our 07B followup of 280 sq.deg. of the UKIDSS Large Area Survey (LAS) produced seven Teff~6000K white dwarfs. In 08B and 10A we confirmed 13 dwarfs, selected from 1400 sq.deg., with 3200<Teff K<5500. Five have Teff<~4000K and cooling ages 8-10Gyr. We ask for a final allocation to followup with GMOS spectroscopy six candidates identified in 2400 sq.deg. of DR8, and to obtain near-infrared photometry for four of these and three from previous searches. We have finetuned our technique so that we are extremely likely to produce cold white dwarfs, significantly adding to the known sample. The results, based on ~half of the final LAS sky, will provide ~10 old dwarfs with ugrizYJHK photometry and optical spectroscopy. The community can apply these findings to other surveys to identify elusive cold Galactic remnants.

Publications using this program's data