VST ATLAS Mike Irwin Nigel Metcalfe Tom Shanks

VST ATLAS Mike Irwin, Nigel Metcalfe, Tom Shanks, et al +2 QDES Michael Drinkwater, Scott Croom et al Featuring Utane Sawangwit, Ph. D

VST ATLAS Survey Ü VST ATLAS (+VHS) ➝ Southern SDSS in ugriz (+YJHK)! Ü Exposures u: 2 x 60 s, g: 2 x 50 s, riz: 2 x 45 s – one filter per hourly concatenations – ugr (dark), iz (gray. bright) Ü Newsflash – ESO Chilean VST time doubles u exposure to 4 x 60 s Ü 2 -tile dither – 84" in Dec, 24" in RA Ü Offsets 58' in RA and Dec – 2' overlap Ü 1"-1. "4 seeing – better than SDSS median 1. "4 –complements KIDS Ü No guide star needed so no overhead Ü ~45 nights per year for 2 years – accelerated! Ü Footprint ~2500 deg 2 in SGC and ~2000 deg 2 in NGC

Omega. CAM 80" gap ~20" gap

VST ATLAS Survey Area b=30 o b=-30 o

VST ATLAS Core Team Ü CASU (Mike Irwin et al, Cambridge) does the basic reduction using the VST Data Flow pipeline Ü Steve Maddox (Nottingham) leads the overall global calibration process Ü Nigel Metcalfe + Peter Draper (Durham) – OB submission + QC on the ATLAS products Ü WFAU (Bob Mann et al, Edinburgh) to provide archiving facilities, additional to the ESO archive

VST ATLAS Status – 6/2/12 ~750 deg 2 ugriz observed

SDSS-ATLAS zoom - r SDSS ATLAS

SDSS-ATLAS zoom - g SDSS ATLAS

SDSS-ATLAS zoom - u SDSS ATLAS

ATLAS CASU ids – improve! ATLAS ids ATLAS

WHDF v ATLAS + SDSS - u

WHDF v ATLAS + SDSS – b vs g D. Karagiannis et al

WHDF vs ATLAS+SDSS – i

ATLAS Science Summary Ü VST ATLAS – "Southern Sloan" – SDSS depth + ~1. "2 resolution in ugriz over ~4500 deg 2 Ü Cosmology Package to rival WFIRST! Ü 2 QDES survey of up to ~500000 QSOs Ü Ü BAO at z~1. 6 via ATLAS+2 d. F UVX QSO clustering Gravitational Growth rate at z~1. 6 via QSOs QSO Lensing vs galaxy ugriz. YJHK photo-z Probe of primordial large-scale Non-Gaussianity Ü ISW via LRGs Ü Other Science Ü Stellar Streams + Galactic Archaeology Ü Z~7 QSOs via ATLAS+VHS z dropouts Ü Beyond the Great Attractor + Fornax etc

2 QDES BAO vs BOSS Ü 80 deg-2 0. 4<z<2. 2 +3000 deg 2 Ü ~3 s BAO detection Ü ⇒± 3% BAO Ü 105 deg-2 1<z<2. 2 and 4500 deg 2 Ü ~6 s BAO detection Ü ⇒± 1. 7% BAO Sawangwit et al (2012), MNRAS, 420, 1916

2 QDES BAO vs BOSS Ü 80 deg-2 0. 3<z<2. 2 + 3000 deg 2 Ü ~3 s BAO detection Ü ⇒± 3% BAO Ü 105 deg-2 1<z<2. 2 + 4500 deg 2 Ü ~6 s BAO detection Ü ⇒± 1. 7% BAO Ü Competitive with BOSS! Sawangwit et al (2012), MNRAS, 420, 1916

2 QDES Pilot: 5 ATLAS fields → 2 d. F

ATLAS 2 QDES ugri QSO selection Ü Simple selection in ugr and gri Ü + KDE selection of Bovy et al Ü Limit g<22. 5

2 QDES 2 d. F AAOmega Pilot Ü 50 min exposure on 20 December AAT Director's night Ü ATLAS field observed at RA 2 h 30 Dec-30 Ü 176 high quality QSO spectra observed! Ü ~66% QSO in fibres 1 -200 but 38% QSO in fibres 201 -400 Ü 2 d. F fibre positional problem – no guide stars in N half Ü Assuming 66% -> already achieving ~80 deg-2 Ü Compare to ~105 deg-2 required to beat BOSS

Pilot Sample QSO Spectra

VST ATLAS 2 QDES Pilot Loss of fibre flux caused by lack of allocated guide stars in Northern half of 2 d. F field

Fibre-ATLAS mag v fibre no. Significant light loss in fibres 201 -400 caused by unallocated guide stars in half the field

2 MASS v ATLAS astrometry check

AAOmega Pilot z vs 2 QZ z

AAOmega Pilot QSO N(z)

AAOmega Pilot QSO n(g) ~50% success rate being maintained at g~22 in only 50 min exposure

Summary Ü ~750 deg 2 surveyed by ATLAS already Ü More or less achieving SDSS depth in ugriz Ü Chilean proposal to double u exposure time accepted Ü 2 d. F AAOmega pilot already hitting QSO sky density of 80 deg-2 to g~22 in 50 min exposure Ü 105 deg-2 1<z<2. 2 QSO target for April run Ü 2 QDES survey of ~0. 5 million QSOs still a possibility… Ü … for z~1. 6 6 s BAO, RSD, QSO Lensing + f. NL+ QSO BH-halo mass relation