The upgraded HET Hobby-Eberly Telescope Dark Energy Experiment

You are Here Dark Energy Dominates Inflation?? Big Bang

What Controls the Expansion Rate An Equation is worth a 1000 pictures: Expansion Rate Radiation Matter Universe Shape Dark Energy Observing different epochs in the Universe allows us to see the influence of different components. HETDEX probes early epochs, where shape is important. time

Artist Rendition of the Multiverse

Dark Energy Ideas Cosmological constant Modification of General Relativity Quintessence; a fifth force Leaking dimensions Big Bang is modified Hubble Bubble Leaking energy from other universes

HETDEX is: blind spectrographic survey on 9.2m Hobby-Eberly Telescope 300 square degrees in 1400 hours (140 nights) over 3 years (taken in 4000 pointings of 20 minutes each); at 1/5 fill, this provides 60 sq deg of sky with spectra about 0.7 million redshifts from 1.9<z<3.5 (Ly-alpha emitters) about 1 million redshifts from 0<z<0.5 (OII emitters) upgraded HET with new top-end, including 22’ field new instrument VIRUS which is 150 spectrographs (R=750 from 350nm – 550nm), covering 1/5th of the focal plane with 33,500 fibers one unit spectrograph has been in use since 2006 TIMELINE: 2016-2019

HETDEX Funding and Budget Private 13.0 NSF 8.0 Air Force (NESSI) 4.5 UT 11.0 Munich, AIP 4.0 TAMU 1.0 Oxford 0.5 Total 42.0 M HET upgrade 17.0 VIRUS 15.0 Software 4.0 Project Office 6.0 Total 42.0 M Schedule Take down 7/13 First light 10/15 20 spectrographs 10/16 156 specs 8/17 Survey 2016-2019

Wide Field Corrector Focal Plane Tracker Optical Fibers Spectrographs (VIRUS) Primary Mirror

ESSENCE of HETDEX 380,000 years after the Big Bang There is a characteristic scale imprinted in the distribution of matter. It acts like a fingerprint that we use to trace over cosmic time. Requires about one million galaxies in order to see it. Today: 13.7 billion years after the Big Bang

Example data from a week ago!

The Instrument for HETDEX: VIRUS Visible Integral-field Replicable Unit Spectrograph Uses idea of industrial replication 150 copies of a simple spectrograph We’re the only ones doing this Huge advantages Cost savings, schedule, low risk Build a prototype Funded by the George & Cynthia Mitchell Foundation, McDonald Observatory, MPE, and AIP VIRUS Prototype

Integral Field Unit production Each IFU is a bundle of 448 fibers split into two slits to feed a VIRUS pair Simple design maximizes throughput and minimizes cost Development in collaboration with AIP nine already delivered IFU input heads IFU input IFU output

Example data frame (2.9 million of these in total)

What Can HETDEX Do For You Detection of dark energy Shape of Universe (curvature) to 0.1% Best measure of shape of matter distribution early in the Universe. Best measure of total neutrino mass Detection of cosmic web in emission Nature of early galaxies Black Hole-Galaxy correlations Star formation at late times Dark matter in nearby galaxies Stellar populations at large radii Map nearby clusters Galactic structure from stellar kinematics Study of the first stars