Next Generation Deep 2 Survey: Reconnoitering the Dark Ages

Jeremy Mould, Swinburne UniversityRecent Progress in theoretical and observational cosmologyBeijing, Nov 6, 2011

A vital goal of astronomy today is to understand the evolution of galaxies

The earliest galaxies emit in the infrared where for maximum sensitivity telescopes should be based in Antarctica

The End of the Dark Ages: First Light and Reionization

Until around 400 million years after the Big Bang, the Universe was a very dark place.  There were no stars, and there were no galaxies.

Scientists would like to unravel the story of exactly what happened after the Big Bang. 

The PILOT survey telescope and the James Webb Space Telescope will pierce this veil of mystery and reveal the story of the formation of the first stars and galaxies in the Universe.

Spectra and images of the first galaxies

JWST PILOT Survey Telescope

http://www.aao.gov.au/pilot/

Project Leader: John StoreyProject Manager: Roger HaynesTelescope Scientist: Will Saunders

The PILOT telescope is to be erected on a tower on the Antarctic plateau, as that is how and where the best images are obtained.

UKIDSS

•7500 square degrees of the Northern sky, extending over both high and low Galactic latitudes, in JHK to K=18.3.

•three magnitudes deeper than 2MASS.

•UKIDSS = near-infrared SDSS

•Also a panoramic atlas of the Galactic plane.

•UKIDSS = five surveys

•two deep extra-Galactic elements, one covering 35 square degrees to K=21, and the other reaching K=23 over 0.77 square degrees.

The Current State of the ArtVIKING - VISTA Kilo-Degree Infrared Galaxy

Survey. PI Will Sutherland

The VIKING survey will image the same 1500 square degrees of the sky in Z, Y, J, H, and Ks to a limiting magnitude 1.4 mag deeper than the UKIDSS Large Area Survey.

• very accurate photometric redshifts, especially at z > 1, important step in weak lensing analysis and observation of Baryon Acoustic Oscillations.

• Other science drivers include the hunt for high redshift quasars, galaxy clusters, and the study of

• galaxy stellar masses.

PILOT 2 survey• Offner relay reflective cold stop design (diffraction limited) by Jon Lawrence

• On chip guiding

• 8K x 8K arrays => 16'x 16' @ 0.125"/pixel

• Assumed K background 1mJy/ם" i.e. 14.54 mag.

• 0.2 arcsec aperture background is K = 14.54 - 2.5log(0.01) = 20.8 mag

• NICMOS sensitivity is H = 25, gives S/N = 0.5 in 900s with background adjusted for aperture.

• To reach S/N = 2 =>16 times longer, that is 4hr.

Image Quality Tip-Tilt removed PSF from SPIE 4836

D

Diffraction limited

Best 25% South Pole

arcsec

The other two curves areMK and average SP

23 nJy is K = 26.2 mag

PILOT survey NIRSpec 70 nJy 2 sr

Plan AClone the GSAOI

focal plane

TypeRockwell HAWAII-2RG HgCdTe 

Array sizes2048 x 2048 pixels each (2040 x 2040

active)

 Detector area 4080 x 4080 pixels (~ 85" x 85")

Physical Pixel size 18 μm

Pixel scale 0.02" (TBC)

Spectral Response 0.9  μm to 2.6 μm (data / plot)

Gains~ 2.8 e-/ADU (TBC)

 Dark current  ~ 0.01 e-/s/pix (~12 e- in the maximum

integration time of 20 minutes)

 Saturation ~ 48,000 ADU (TBC)

On-Detector Guide Windows (ODGW)

 One programmable ODGW per detector

6/04/11

Cost of Infrared Camera

• $750,000 per 20482

• $125,000 per ASIC (one for each chip)

• 40962 totals $3.5M (8.5 arcmin field)

• 2 x 40962 totals $7M (8.5 x 17 arcmin)

• Plus cost of dewar and filters

• Plus cost of labour

Plan BSOFRADIR SATURN SW HgCdTe SWIR

ARRAY FEATURESFormat: 1000x256Pixel pitch: 30 µmx30 µmMaterial spectral response: 0.8µm – 2.5 µmFPA Operating Temperature: up to 200 KROIC FEATURESModes: snap shot operation, integrate while read mode, programmable integration time, anti blooming systemInput stage: Capacitance TransImpedance Amplifier (CTIA)Charge handling capacity: 0.4 106 / 10.6 106 (for 100% well fill)Electrical dynamic range: > 2 V (75 dB)Readout noise: < 150 e- (for 0.4 Me- gain) and < 450 e- (for 1.6 Me- gain)Signal outputs: 4 or 8 (user selectable)

6/04/11

Science Goals

• Although there are many science goals for a survey deeper than any previous one,

• e.g. the lowest mass stars

• Star formation regions in our galaxy

• See also ARENA and Dome F proposals

• one of the most exciting is finding galaxies at redshift > 10 from the H dropout method.

• These have no flux at 1.6• But are detected at 2.2• Redshift = 1.6/0.09 – 1 = 16.8

• Spectra of these objects would be obtained with JWST

The Antarctic advantage

• Almost diffraction limited images

• Wide field

• Low 2 background

• This combination is only available from

• the Antarctic plateau

• high altitude balloons

• spaceMore details http://www.kdust.org/KDUST/KDUST.html and arXiv:1108.1992

The competition is space: WFIRST

Exoplanets and dark energy

WFIRST (or Euclid) vs PILOT

Advantages of WFIRST

•Top ranked in ASTRO 2010

•Broader band possible, e.g. 1.6-3.6

•No clouds

Disadvantages of WFIRST

•Smaller aperture, 1.5 metre

•Lower resolution

•3 year mission lifetime

•2020 launch

•Order of magnitude higher cost

•200 nJy limit vs 70 nJy with PILOT

PILOT Survey logistics• Implement 20’ field: 26 years/sr

• assuming 180 x 24 clear hours per year

• but that’s probably faster than WFIRST

• ARENA’s PLT design offers 40’, 6 years/sr

• If K background is 0.1mJy/sq” then 0.26 years/sr• other wavelengths also become doable in a 5 year ‘mission’

• ~100 Pb of data to cover 2 sr

• not a problem according to Moore’s Law

• data could be served from CAASTRO website

• Will not be obsolete until KDUST 8 is operational

• That will reach ABK = 29 mag

Stellar pops in the EOR

2 micron background

Denizens of the epoch of reionization

• 1 band dropouts at z = 1.1/0.09 -1 = 11

• J band dropouts at z = 1.4/0.09 -1 = 14

• Galaxies with 108 year old stellar pops at z = 6

• Pair production SNe (massive stars) at MK = -23

• Activity from progenitors of supermassive black holes

• Young globular clusters with 106 year free fall times and M/L approaching 10-4

• Rare bright objects require wide field survey, then JWST or GMT spectra.

The next steps

• Is this project compatible with KDUST 2.5 ?

• Finalize camera configuration

• Find LIEF partners

• Swinburne University, J. Mould

• UNSW, M. Burton

• Macquarie University, J. Lawrence

• Melbourne University, S. Wyithe

• ANU, P. McGregor

• CAASTRO and AAO ?

• Texas A & M University

ARC LIEF facts of life

• $9M is a very big proposal

• Funding spread over 2013,4,5

• But the chips need purchasing in 2013

• Most proposals are unfunded

• This proposal needs to be very strong

• Universities must contribute 25% cash

• CAASTRO may be able to contribute a postdoc

Construction and operations schedule (tentative)

• January 2013 LIEF funding

• Preliminary Design Review

• 2013 Texas A & M purchases Teledyne arrays

• ANU purchases dewar and filters

• 2014 Integrate and test focal plane at ANU

• January 2015 Integrate telescope and camera in Fremantle

• 2015-2019 operations (within the international antarctic science region) at Kunlun Station

• 2020 return of focal plane to USA