WFMOS KAOS concept identified via the Gemini Aspen Process and completed a Feasibility Study (Barden et al.) Proposed MOS on Subaru via an international collaboration of Gemini and Subaru 1.5deg FOV with 4500 fibres feeding 10 low-res spectrographs and 1 high-res spectrograph First-light in 2012 ~20000 spectra a night (2dfGRS at z~1 in ~10 nights) DE science, Galactic archeology, galaxy formation studies and lots of ancillary science from database Concept Design phase (2 teams) with funding decision next year? SUBARU Matthew Colless & Sam Barden

WFMOS baseline Top-level design performance guidelines for WFMOS  Wavelength range: 0.39–1.0µm  Field of view: ~1.5deg diameter  Spectral resolution: R ~ 1000–30,000 (or 40,000)  Simultaneous targets:

A bit of history….  WFMOS was a proposed second-generation Gemini instrument that emerged from the ‘Aspen’ process Before that, it was the KAOS conceptual instrument Originally for Gemini, sharing of Gemini/Subaru resources was recognized in 2004  WFMOS underwent a feasibility study (Barden et al. 2005; Bassett, Nichol & Eisenstein 2006), completed in March Fully reviewed and recommended WFMOS move to full concept design review Subaru/Gemini DE meeting in Hawaii in November 2005 (over 80 participants from Japan, UK, US, Australia, Canada). Recent GA science meeting. Two teams have formed and submitted proposals for WFMOS Concept Design; To start in earnest in 2007 PPARC Council “ commitment of up to $18M for the UK share of the Gemini 'Aspen' programme, the full commitment being contingent on the Wide Field Multi Object Spectrograph (WFMOS) instrument proceeding ”.

Baryon Acoustic Oscillation Gravity squeezes the gas, pressure pushes back! They oscillate When the Universe cools below 3000K these sound waves are frozen in Courtesy of Wayne Hu

STANDARD RULER 4.7% measurement 4.7% measurement of the distance to z=0.35 (effective redshift of LRGs) 3.7% measurement 3.7% measurement of relative distance to z=0.35 and the CMB (most robust measurement) Universe is flat to 1% Assuming w=-1, in conjunction with the WMAP & Tegmark et al. (2004), the geometry of the Universe is flat to 1% All this from a 3  detection!

KAOS purple book (Seo, Eisenstein, Blake, Glazebrook) WFMOS will measure w to <4% and dw/dz to <15% DE Science Measure BAO at z~1 and z~3 to determine w(z)

DE Physics DGP LCDM 7  difference Yamamoto et al. 2006

WFMOS Legacy Facility instrument Galaxy Evolution: Every galaxy in Coma (M r < -11) IGM and Quasars: Simultaneously observing QSOs and galaxies in the same fields Calibrate photo-z’s: LSST and DES require >10 5 unbiased redshifts z rangeR limit (AB) Volume (h - 1 Gpc) Area (sq degs) NumberNights Galaxy Archeology (Glazebrook et al. 2005)

Few thousand z~1 SNe detected via their spectroscopy Alcock-Paczsynki test (Yamamoto et al. 2004, Matsubara 2004) High-z cluster counts (Newman et al. 2002) Reciprocity relation d A /d L = (1+z) 2 (Bassett & Kunz 2004) WFMOS Legacy Archival science

Conclusion  With WiggleZ, FastSound, WFMOS can deliver tight constraints on dw/dz (testing DE beyond w=constant & modified gravity)  WFMOS is “alive and kicking” Concept Design teams eager to begin hard work of finalizing the design of science and instrument  Challenges ahead include: What targets? HSC+WFMOS looks attractive (SDSS at z~1) Cost! Clear statement from agencies helps morale. Teams will scrutinize costs.  Highly successful science meetings (lots of goodwill and students!)