Jim Geach on behalf of the S2CLS consortium The SCUBA-2 Cosmology Legacy Survey

What is the SCUBA-2 Cosmology Legacy Survey? Largest of the JCMT Legacy Surveys: 65% of all SCUBA-2 time to be spent on JLS, over half this is spent on CLS CLS (high redshift)1778 hours50.9% GBS (local star formation)412 hours11.8% SASSy (‘all/ambitious’ sky survey)480 hours13.8% NGLS (nearby galaxies)100 hours2.9% JPS (Galactic plane)450 hours12.9% SONS (stars)270 hours7.7% 3490 hours291 nights

What is the SCUBA-2 Cosmology Legacy Survey? Simple two tier strategy covering well-known fields: Wide survey at 850um in grade 2-3 conditions Target area 10 deg 2 (probably get 50% of this) Uniform coverage to 1sigma=1.2mJy. PONG mapping. ~80% complete Deep survey at 450um + 850um in grade 1 conditions Target area 0.25 deg 2 Uniform coverage 450um, confusion limited at 850um. DAISY mapping. ~50% complete

Science drivers Comprehensive survey of SMGs detected at 850um (N~10 4 ) over several ~degree scale fields ‣ measure clustering / halo properties ‣ constrain bright-end counts ‣ reliably probe properties of fainter SMGs (3-5mJy) ‣ AGN/starburst connection, transition objects ‣ ‘very’ high-z science (IR luminosity density at z>5, rare objects) ‣ cross-correlation studies ‘Keyhole’ confusion limited survey at um ‣ properties of 450um-selected SMGs below HSO confusion limit ‣ resolving CIB at 450um (closer to peak) ‣ probing very faint end of counts (P(D) analyses) ‣ joint stellar/dust/gas morphologies (CANDELS overlap, ALMA)

Targets ‣ COSMOS (2 deg) ‣ UKIDSS-UDS/SXDF (1 deg) ‣ GOODS-N ‣ Extended Groth Strip / AEGIS ‣ Akari-NEP ‣ Lockman Hole Owen ‣ SSA22 Including deep CANDELS Other wide fields

EGS UDS Lockman Hole SSA22 Akari-NEP COSMOS 1 degree

Average cost of an SMG: £400* Legacy value: priceless *don’t quote me on this

S2CLS is a ‘factory’ for detecting dusty starbursts at z>1 Excellent ancillary data (e.g. CANDELS) probing stellar emission, redshifts, morphologies ALMA offers HST-matched resolution: directly compare dust and gas to stellar emission on sub- galactic scales Pinpoint counterparts with ~few asec accuracy

Cumulative area ~3 deg 2 at rms<2mJy… improvement over SHADES by order of magnitude

Why are we doing this? Dole+06 Integrated over the history of the Universe, 1 in 2 photons generated from SF is emitted in the FIR

Dole+06 Integrated over the history of the Universe, 1 in 2 photons generated from SF is emitted in the FIR Why are we doing this?

ULIRG LIRG JEG+Papadopoulos 12 Negative k-correction at 850um provides uniform luminosity selection at fixed flux limit out to z~10! Huge volume column. At z>2, bulk of IR luminosity density is emitted by ULIRGs: epoch of formation of most massive galaxies today Why are we doing this? Observed 850um flux density Bethermin+11

Early science highlights and prospects

Cycle 1 ALMA follow-up of CLS sources at sub-arcsec resolution Cycle 1 ALMA follow-up of CLS sources at sub-arcsec resolution

First measurement of 450um number counts JEG Directly resolve ~15% of 450um Recover ~50% with MIPS stack Herschel SCUBA-2 JEG+ 2013

Average sub-mm flux of Lyman Break Galaxies Coppin, JEG arXiv: Stacked LBGs in SXDF at z=3, 4, 5 (850um) Typical S 850 ~ mJy

Cross-correlating galaxies with CLS Smith, JEG in prep

SCUBA-2 SAURON/FORS Rare objects: Lyman-alpha Blobs JEG+ 2014

Next steps… Clear need to complete COSMOS field – tremendous legacy value in this field (including HSC UD). Would require at least another winter (probably two) to reach full CLS depth. Complete the deep mapping of CANDELS fields – progress has been severely hampered by poor weather. Complement to HSC UD. Obvious continuation of CLS would be wider area – mapping of all HSC deep fields to ~30 deg 2 ? Time investment would be ~1000s hours for useful depths.