HET Dark Energy Experiment Bárbara G Castanheira The University of Texas at Austin Universität Wien 17 th European White Dwarf Workshop Tübingen August 1620 2010 Hobby Eberly ID: 269669
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Slide1
White Dwarfs in the HET Dark Energy Experiment
Bárbara G. Castanheira
The University of Texas at AustinUniversität Wien
17th European White Dwarf Workshop – Tübingen, August 16-20, 2010 Slide2
Hobby-
Eberly Telescope
Location: McDonald Observatory (30° 40' N)Low cost: 15-20% of the cost of a 9 m telescope
Primary mirror: 11.1 x 9.8 m (9.2 m effective aperture)91 hexagonal mirrorsFixed elevation angle of 55o (tilted Arecibo design)
Access 81% of the sky
Queue schedule
Instruments: HRS, LRS, MRS
Model for SALT
17
th
European White Dwarf Workshop –
Tübingen
, August 16-20, 2010 Slide3
HETDEX: HET Dark Energy Experiment
Goal: probe dark energy
Observations: ~ 1400 hours in 3 yearsTechnique:
expansion of the universe at 0<z<4Main targets: Lyman-α emitting galaxies
17
th European White Dwarf Workshop –
Tübingen
, August 16-20, 2010
(Hill et al. 2008)Slide4
Dark energy: 17
th European White Dwarf Workshop – Tübingen, August 16-20, 2010
Supernovae discovery of accelerated expansionWithin GR: smooth energy with large negative pressure
75% of the universeAcceleration began at z~0.4 and t~10GyrSlide5
(
Frieman et al. 2008)
17th European White Dwarf Workshop – Tübingen, August 16-20, 2010 Slide6
17
th European White Dwarf Workshop – Tübingen, August 16-20, 2010
Destiny of the universe depends critically upon the nature of dark energy!Slide7
17
th European White Dwarf Workshop – Tübingen, August 16-20, 2010
HETDEX field:Slide8
VIRUS-P Review:
Visual Integral-field Replicable Unit Spectrograph - Prototype
1.9’x1.9’ FOV at
2.7 m HJST1/3 fill
factor
Largest
FOV of any existing
IFU
4.2
’’ diameter
fibers
on
sky
3500-5800Å
wavelength
range
R=1000
@ 5000Å
17
th
European White Dwarf Workshop –
Tübingen
, August 16-20, 2010 Slide9
Flux calibrating the
pilot survey:
17th European White Dwarf Workshop – Tübingen, August 16-20, 2010
Feige 34 Slide10
17
th
European White Dwarf Workshop –
Tübingen, August 16-20, 2010 Dither 1:Slide11
17
th
European White Dwarf Workshop –
Tübingen
, August 16-20, 2010
Dither 2:Slide12
17
th
European White Dwarf Workshop –
Tübingen
, August 16-20, 2010
Dither 3:Slide13
17
th
European White Dwarf Workshop –
Tübingen
, August 16-20, 2010
Dither 4:Slide14
17
th
European White Dwarf Workshop –
Tübingen
, August 16-20, 2010
Dither 5:Slide15
17
th
European White Dwarf Workshop –
Tübingen
, August 16-20, 2010
Dither 6:Slide16
17th
European White Dwarf Workshop – Tübingen, August 16-20, 2010
Feige 34:VIRUS-P2.7m HJST
6x120sV=11.2 Slide17
17
th European White Dwarf Workshop – Tübingen
, August 16-20, 2010 HETDEX details:
150 VIRUS3500-5500Å~3400 spectraFOV 22arcminResolution ~5Å
~140 nights, 3 years
PARALLEL SURVEYSlide18
(
Drory 2010)17th
European White Dwarf Workshop – Tübingen, August 16-20, 2010 Slide19
17th European White Dwarf Workshop – Tübingen
, August 16-20, 2010 White Dwarfs in HETDEX
~20000 White DwarfsMagnitude limited sample
For V=22, S/N=3Main and Parallel surveysA powerful survey!Slide20
17th European White Dwarf Workshop – Tübingen
, August 16-20, 2010 HETDEX current status:
Schedule: late 2011VIRUS-P at HET
Replication of spectrographsSoftware (CURE or VACCINE & DIAGNOSE)Additional scienceSlide21
17th European White Dwarf Workshop –
Tübingen, August 16-20, 2010 White dwarf science goals:
WD Luminosity FunctionNew candidates of
pulsators (2.1m)New “flavors” of WDs?Slide22
17th European White Dwarf Workshop –
Tübingen, August 16-20, 2010 barbara@astro.as.utexas.edu
Danke! Obrigada
!