Abstract

Targeting white dwarf stars in the HET Dark Energy Experiment

Barbara Castanheira (The University of Texas at Austin)

D. E. Winget - The University of Texas at Austin

In the past decade, large scale surveys have discovered a large number of white dwarf stars. Many new aspects have been revealed, including the discovery of the DQVs, close-in non-contact binary systems, and debris disks around many stars. Unfortunately, the population statistics of the newly discovered white dwarf stars are unknown, because of the various methods used to assign objects to fibers for spectroscopic observations in the SDSS survey. A white dwarf sample that is magnitude limited with well-constrained selection criteria, is needed. The HET Dark Energy Experiment (HETDEX) will use the 9.2 m HET at McDonald Observatory and a set of more than 100 spectrographs to map the three-dimensional positions of one million galaxies, to probe dark energy. In this unique magnitude limited survey, all objects that fall into the fibers will be observed. We expect to observe spectroscopically about 10,00 white dwarf stars.In this paper, I will present the specifications and current status of HETDEX, which will start taking data in Fall 2014. I will also show our first results from observations of white dwarf stars using an identical spectrograph with the 2.7m HJS Telescope and discuss some of the approaches we have been working on in preparation for this exciting survey.

Mode of presentation: oral