Gary Hill, Texas ()
"The Hobby-Eberly Telescope Dark Energy Experiment"
Abstract. The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) aims to make a direct detection of dark energy at z~3, in the case that it is a cosmological constant. HETDEX uses baryonic acoustic oscillations and the shape of the Lyman-alpha emitting (LAE) galaxy power spectrum to constrain H(z) and Da(z) to percent levels. As a result, the experiment will place tight constraints on possible dark energy evolution, complementing studies of the phenomenon at lower redshift. HETDEX will also provide the most accurate constraint on the curvature of the Universe.HETDEX will outfit the upgraded 10 m HET with a new wide field and an array of at least 150 integral-field spectrographs to survey a 400 sq. degree area in the north galactic cap. Each fiber-coupled unit spectrograph will cover 350-550 nm, simultaneously at 6 A resolution, providing more than 36,000 spectra per exposure. This instrument, called VIRUS, will enable blind spectroscopic surveys over wide area for the first time, and in particular will be used to detect ~0.8 million LAE galaxies with 1.9 < z < 3.5 and more than a million [OII] emitting galaxies with z < 0.5. The 3-D map of LAE galaxies in 9 cubic Gpc volume will be used to constrain the expansion history at this early epoch.The prototype of the VIRUS unit spectrograph (VIRUS-P) is a powerful instrument in its own right. Used on the McDonald 2.7 m Smith Telescope, it covers the largest area of any integral field spectrograph, and has coverage down to 340 nm. It is currently in use for a pilot survey to better measure the properties of LAE galaxies in support of HETDEX, among other investigations where it is uniquely powerful.I will describe the motivations for HETDEX, the engineering behind VIRUS, and results from the Pilot Survey. I will look forward to completion of VIRUS on the upgraded HET as a unique facility in astronomy and to the niche that such replicated instruments can have on future ELTs.
Held in the AAO Conference room at 03:30 PM on Friday, 26 November 2010back