Hobby-Eberly Telescope Dark Energy Experiment

1
The upgraded HET
Hobby-Eberly Telescope Dark Energy Experiment
2
You are Here
Dark Energy Dominates
Inflation??
Big Bang
3
Artist Rendition of the Multiverse
4
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

5
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 1.9ltzlt3.5
  (Ly-alpha emitters)
• about 1 million redshifts from 0ltzlt0.5 (OII
  emitters)
• upgraded HET with new top-end, including 22
  field
• new instrument VIRUS which is 150 spectrographs
  (R750 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
6
HETDEX Funding and Budget
Funding
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 2/16
156 specs 8/16
Survey 2016-2019
7
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
8
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
9
Wide Field Corrector
Focal Plane
Tracker
Optical Fibers
Spectrographs (VIRUS)
Primary Mirror
10
The Instrument for HETDEX VIRUS

• Visible Integral-field Replicable Unit
  Spectrograph
• Uses idea of industrial replication
• 150 copies of a simple spectrograph
• Were 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
11
(No Transcript)
12
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
13
The upgraded HET
Hobby-Eberly Telescope Dark Energy Experiment