The Luminosity Function for White Dwarfs in the SuperCOSMOS Sky Survey

Abstract

We present the techniques and early results of our program to measure the luminosity function for White Dwarfs in the SuperCOSMOS Sky Survey. Our survey covers over three quarters of the sky to a mean depth of I~19.2, and finds ~9,500 Galactic disk WD candidates on applying a conservative lower tangential velocity cut of 30kms^-1. Novel techniques introduced in this survey include allowing the lower proper motion limit to vary according to apparent magnitude, fully exploiting the accuracy of proper motion measurements to increase the sample size. Our luminosity function shows good agreement with that measured in similar works. We find a pronounced drop in the local number density of WDs at a M_bol~15.75, and an inflexion in the luminosity function at M_bol~12.

8 pages, 7 figures. To appear in Proceedings of the 16th European Workshop on White Dwarfs, held in Barcelona, June 30th-July 4th, 2008. Journal of Physics Conference Proceedings (JPCS)

References in corpus (9)

• The SuperCOSMOS Sky Survey. Paper I: Introduction and Description
• Photometric and Spectroscopic Analysis of Cool White Dwarfs with Trigonometric Parallax Measurements
• The White Dwarf Luminosity Function from SDSS Imaging Data
• The White Dwarf Cooling Sequence of NGC6397
• The SuperCOSMOS Sky Survey. Paper III: Astrometry
• Model Atmosphere Analysis of Two Very Cool White Dwarfs
• The White Dwarf Cooling Age of the Open Cluster NGC 2420
• Ages of White Dwarf-Red Subdwarf Systems
• New Techniques to Determine Ages of Open Clusters Using White Dwarfs