Der Paul van der Werf Sterrewacht Leiden The SCUBA2 Cosmology Legacy Survey - to coldly go where no man has gone before… Xining August 20, 2007

Paul van derder Werf

Sterrewacht Leiden

The SCUBA2 Cosmology Legacy Survey -The SCUBA2 Cosmology Legacy Survey -to coldly go where no man has gone to coldly go where no man has gone

before…before…

XiningXining

August 20, 2007August 20, 2007

SCUBA-2 Cosmology Legacy SurveySCUBA-2 Cosmology Legacy Survey 2

OutlineOutline

Reasons for submm surveysReasons for submm surveys

A survey of SCUBA surveysA survey of SCUBA surveys

SCUBA-2 Cosmology Legacy SurveySCUBA-2 Cosmology Legacy Survey

850 850 m survey sciencem survey science

450 450 m survey sciencem survey science


A clear view out to reionizationA clear view out to reionization


Much of cosmic star formation Much of cosmic star formation history is obscuredhistory is obscured

(Hughes et al., 1998)


A challenge to galaxy formation modelsA challenge to galaxy formation models

Integral under green curve Integral under green curve would exceed local would exceed local stellar mass estimates stellar mass estimates for normal IMF.for normal IMF.

SFR implied by SMG’s


SCUBA surveysSCUBA surveys Many teams, many surveysMany teams, many surveys Blank field surveys Blank field surveys

(confusion-limited)(confusion-limited) Gravitationally lensed Gravitationally lensed

surveyssurveys Few 100 SMGs detectedFew 100 SMGs detected Small field Small field slow buildup slow buildup

of samplesof samples


Early surveysEarly surveys

Clusters – Smail et al. (1997) HDF – Hughes et al. (1998) Canada-UK Deep Submm Survey (CUDSS) – Eales et al. (2000) Hawaii Flanking Fields survey – Barger et al. (1998) 8-mJy survey – Scott et al. (2002) 8-mJy IRAM Mambo follow-up – Greve et al. (2004) SCUBA-Leiden Lens Survey – Knudsen et al. (2006) combined analysis of all SCUBA blank-field surveys – Scott et al. (2006)

+ enormous efforts in follow-up: IDs: K-band (Smail, Knudsen), radio (Ivison) redshifts: radio-submm (Carilli, Yun) and spectroscopic (Chapman)


A survey of SCUBA surveysA survey of SCUBA surveys

HDF SHADES

8 mJy


The submillimetre universeThe submillimetre universe

(Coppin et al., 2006)

Estimated background of sources >2mJy is ≈9700 mJy/deg2 so >20-30% of FIRB resolved

Assuming most of these lie at z≈2: co-moving number density of objects forming ≈ 103 M of stars per year is 1-3 ∙10—5 Mpc—3

Comparable to number

density of

2-3 L* ellipticals today


From SCUBA to SCUBA-2From SCUBA to SCUBA-2

Field of view 8’Field of view 8’8’: 108’: 10 SCUBA SCUBA SCUBA-2 brings rectangular array imaging to submm SCUBA-2 brings rectangular array imaging to submm

astronomyastronomy 8 arrays of 408 arrays of 4032 TES detectors – 4 arrays at 850 32 TES detectors – 4 arrays at 850 m, 4 m, 4

at 450 at 450 mm Fully sampled imaging at 850 Fully sampled imaging at 850 mm Per pixel NEP 50 (220) mJy/√Hz at 850 (450) Per pixel NEP 50 (220) mJy/√Hz at 850 (450) mm


SCUBA-2 type surveysSCUBA-2 type surveys

SCUBA-2 field-of-view

1 deg1 deg22 field, will be mapped to confusion field, will be mapped to confusion limit in 23 hours by SCUBA-2 at 850 limit in 23 hours by SCUBA-2 at 850 mm

(from Gastañaga et al.)


Legacy survey processLegacy survey process

Concept of legacy surveys proposed to JCMT boardConcept of legacy surveys proposed to JCMT board Legacy surveys can use both SCUBA-2 and HARP Legacy surveys can use both SCUBA-2 and HARP (16-pixel 350 GHz receiver)(16-pixel 350 GHz receiver) Call for proposals by the board – resulted in Call for proposals by the board – resulted in

oversubscription of oversubscription of all all assumed assumed (usable) JCMT time in 2007-2009 time by factor 5.5(usable) JCMT time in 2007-2009 time by factor 5.5 International workshop in Leiden led to coordinated International workshop in Leiden led to coordinated proposalsproposals Each proposal evaluated by a number of referees from Each proposal evaluated by a number of referees from

outside the JCMT outside the JCMT communitycommunity Process overseen by the JCMT Survey Steering Group, Process overseen by the JCMT Survey Steering Group,

which made a which made a recommendation to the JCMT board, which was adoptedrecommendation to the JCMT board, which was adopted


Outcome of the processOutcome of the process Two sets of surveys: 2-year surveys and 5-year surveysTwo sets of surveys: 2-year surveys and 5-year surveys

Two-year plan approved; 5-year plan approved in principle, but newTwo-year plan approved; 5-year plan approved in principle, but new call for surveys after 2 yearscall for surveys after 2 years

During this period, 55% of the available time on JCMT will go to theDuring this period, 55% of the available time on JCMT will go to the Legacy SurveysLegacy Surveys

Surveys are overseen by the JCMT Survey Oversight Committee,Surveys are overseen by the JCMT Survey Oversight Committee, which advises the JCMT board;which advises the JCMT board; teams will report every six months andteams will report every six months and must demonstrate progress, keeping up with the data stream, ability tomust demonstrate progress, keeping up with the data stream, ability to produce a uniform dataset, etc.produce a uniform dataset, etc.

Data initially proprietary, but obligation to release reduced data Data initially proprietary, but obligation to release reduced data


JCMT Legacy SurveysJCMT Legacy Surveys

Cosmology Legacy SurveyCosmology Legacy Survey (most highly rated): (most highly rated): 490 hours band 1490 hours band 1 (this is 90% of the expected available band 1 time!) (this is 90% of the expected available band 1 time!) and and 630 hours band 2/3630 hours band 2/3 SCUBA-2 All-Sky Survey (SASSy): 500 hours band 4 to 150 mJy depthSCUBA-2 All-Sky Survey (SASSy): 500 hours band 4 to 150 mJy depth (all-sky in 5 years)(all-sky in 5 years) Debris disks – complete set of nearby starsDebris disks – complete set of nearby stars Nearby galaxies survey – SCUBA-2 and HARPNearby galaxies survey – SCUBA-2 and HARP

Gould’s Belt survey (2Gould’s Belt survey (2ndnd highly rated) – SCUBA-2 and HARP highly rated) – SCUBA-2 and HARP Galactic Plane survey – SCUBA-2 and HARPGalactic Plane survey – SCUBA-2 and HARP

Spectral line survey – HARP only Spectral line survey – HARP only


Debris disk surveyDebris disk survey

Few hundred nearby stars,Few hundred nearby stars, mapped to the confusion limitmapped to the confusion limit at 850 at 850 mm

Will likely Will likely produce very niceproduce very nice target set for adaptive opticstarget set for adaptive optics observations of SMGsobservations of SMGs

Fomalhaut at 450m

?

850m

Size of Pluto’s orbit

Beam size

Holland et al. (2001)


SCUBA-2 Cosmology Legacy SurveySCUBA-2 Cosmology Legacy Survey 4 PIs: Jim Dunlop, Mark 4 PIs: Jim Dunlop, Mark Halpern, Halpern, Ian Smail, Paul van der Ian Smail, Paul van der Werf; Werf; + ≈ 100 co-I’s + ≈ 100 co-I’s

SCUBA-2 field-of-view

Time allocation for the 2-Time allocation for the 2-year year program: program: 41 nights band 1 41 nights band 1 weather,weather, 61 nights band 61 nights band 2/32/3

2-year program:2-year program: large survey (20 deglarge survey (20 deg22) at ) at 850 850 m, m, deep survey at 450 deep survey at 450 m m (0.5 deg(0.5 deg22)) 5-year program:5-year program: large survey (50 deglarge survey (50 deg22) at ) at 850 850 m, m, deep survey at 450 deep survey at 450 m m (1.3 deg(1.3 deg22))


Survey propertiesSurvey properties

Survey volumes are always Survey volumes are always very very longlong in the radial direction. in the radial direction. A A deeperdeeper submm survey submm survey

does not does not probe probe a larger volume, buta larger volume, but fainter galaxies at all fainter galaxies at all redshiftsredshifts..

JCMT/SCUBA-2 confusion JCMT/SCUBA-2 confusion

limit limit at 850 at 850 m is 0.8 mJy; to 3m is 0.8 mJy; to 3 we we resolve only resolve only ≈20%≈20% of of background.background. Bright sources are typically Bright sources are typically

20 mJy20 mJy limited dynamic range in limited dynamic range in fluxflux

Wide Wide 850 850 m survey of only m survey of only

1 layer1 layer

(from Andrew Blain)


Survey depths and widths (2-yr plan)Survey depths and widths (2-yr plan)

Wide 850Wide 850 m survey: 20 degm survey: 20 deg22 to 1 to 1 = 0.7 mJy = 0.7 mJy.. Comparable to a Schmidt plate to the depth of the Comparable to a Schmidt plate to the depth of the SCUBA-HDF-N map.SCUBA-HDF-N map. Expected to yield several 10Expected to yield several 1033 sources at >10 sources at >10, several , several 101044 at >3 at >3..

Deep 450Deep 450 m survey: 0.5 degm survey: 0.5 deg22 to 1 to 1 = 0.5 mJy = 0.5 mJy (expected (expected confusion limit).confusion limit). Intended area of SHADES, to average over sufficient Intended area of SHADES, to average over sufficient cosmic volume.cosmic volume. Expected to yield several 10Expected to yield several 1022 sources at >10 sources at >10, several , several 101033 at >3 at >3..

Deep 850Deep 850 m survey: 0.5 degm survey: 0.5 deg22 to 1 to 1 = 0.15 mJy = 0.15 mJy (ignoring (ignoring confusion).confusion). In parallel with 450 In parallel with 450 m map, which will be used for m map, which will be used for deconvolution.deconvolution.


Survey fieldsSurvey fields 850 850 m survey:m survey: 450 450 m survey:m survey:

fieldfield RARA areaarea

[deg[deg22]]

XMM-LSSXMM-LSS 22 55

ECDFSECDFS 33 33

CosmosCosmos 1010 22

LockmanLockman 1010 44

BootesBootes 1414 22

EGSEGS 1414 11

ELAIS-N1ELAIS-N1 1616 22

Akari-NEPAkari-NEP 1818 11

fieldfield RARA areaarea

[deg[deg22]]

UDSUDS 22 <0.25<0.25

ECDFSECDFS 33 <0.25<0.25

CosmosCosmos 1010 <0.25<0.25

GOODS-NGOODS-N 1212 0.050.05

Akari-NEPAkari-NEP 1818 0.020.02

SA22SA22 2222 0.020.02

Field selection (partly) driven by Field selection (partly) driven by complementary data complementary data of theof therequired depthrequired depth; e.g., ; e.g., KKABAB=25=25


Deep Imagingfld R.A. Dec. nuv_exp fuv_exp (deg) (deg) (sec) (sec)00 53.128 -27.87 77404 75206 01 52.012 -28.21 36432 36432 02 53.124 -26.80 8654 8653 03 54.165 -27.31 30870 29769 04 52.926 -28.90 12296 12294 05 52.111 -27.27 12973 12972 06 54.020 -28.33 4408 4406 07 52.100 -29.21 19734 18403 08 53.100 -29.40 20119 18734 09 54.100 -29.03 18746 17579 10 52.900 -27.37 19520 18353

10

87

6

5

4

3

2

10

9

Spectroscopyfld R.A. Dec. nuv_exp fuv_exp (deg) (deg) (sec) (sec)00 53.128 -27.87 183818 135445

CDFS


Deep Imagingfld R.A. Dec nuv_exp fuv_exp (deg) (deg) (sec) (sec)00 162.683 58.72 59686 2956501 160.698 58.51 32358 1527802 161.019 59.44 35054 1621703 159.002 59.20 36602 1621904 161.753 57.89 31828 1529205 163.289 56.95 81761 2875806 158.825 58.13 30102 1643707 164.190 58.27 39192 1437708 160.006 56.60 30456 1306109 163.230 59.77 34518 1551410 161.452 55.97 31870 1275311 164.997 59.19 39774 1498912 159.520 57.76 33851 1522813 157.346 57.42 34150 1465615 163.085 57.88 29738 16937

15

9

8

7 6

5

4

3

1312

11

10

Spectroscopy fld R.A. Dec nuv_exp fuv_exp (deg) (deg) (sec) (sec)00 162.683 58.72 50649 4741205 163.289 56.95 4234 0

Lockman


fld R.A. Dec. nuv_exp fuv_exp (deg) (deg) (sec) (sec)00 36.661 -4.48 69679 6369401 36.361 -4.48 62332 4193702 36.582 -5.51 1701 170103 35.472 -5.52 4860 486004 34.915 -5.10 8715 856005 36.481 -3.60 8446 844606 34.600 -3.65 8778 862207 34.100 -5.83 8502 842508 35.057 -6.30 10568 1033509 34.118 -4.64 9120 736712 33.661 -3.68 9842 960919 35.430 -3.15 8465 799120 35.650 -4.65 7603 7369

2

20

19

12

9

8

7

65

4

3

XMM-LSS


fld R.A. Dec. nuv_exp fuv_exp (deg) (deg) (sec) (sec)00 243.403 54.98 14568 1640001 241.960 55.63 16713 17902 241.722 54.58 14825 003 245.149 55.89 13963 7904 243.276 53.89 14269 4005 243.158 56.54 16173 41206 241.500 56.60 15968 18007 244.709 55.10 14272 58408 241.009 55.05 15686 18109 241.607 53.53 13341 4210 240.400 53.79 13573 011 242.820 52.90 16274 4012 244.112 54.00 16823 82

9

87

65

4

3

2

1

12

11

10

ELAIS-N1

(FUV for Tadpole in field 1 is still missing)


Science case 850 Science case 850 m surveym survey

Clustering of SMGsClustering of SMGs

Relation with other populations through massive source stackingRelation with other populations through massive source stacking

Extreme objects (>30 mJy) – how many? what are they?Extreme objects (>30 mJy) – how many? what are they?

1010 detections: easier identification, better photo- detections: easier identification, better photo-zz

Properties of host galaxies – stellar masses, Properties of host galaxies – stellar masses, KK——zz diagram, growing AGN? diagram, growing AGN?

New tests for semi-analytical modelsNew tests for semi-analytical models

Rich source of follow-up by e.g., ALMARich source of follow-up by e.g., ALMA


Clustering and evolutionClustering and evolution

Clustering signal even Clustering signal even without without any redshift informationany redshift information

Photo-Photo-zz’s ’s clustering as clustering as function of function of zz

Assign halo masses to Assign halo masses to SMGsSMGs

Same at all redshifts?Same at all redshifts?


Relations between source populationsRelations between source populations Availability of very deep data from e.g., UDS and IRAC allows recoveryAvailability of very deep data from e.g., UDS and IRAC allows recovery of submm signal from a selected population. of submm signal from a selected population.

E.g.: Lyman Break Galaxies have no detectable submm emission even afterE.g.: Lyman Break Galaxies have no detectable submm emission even after massive source stacking, but Distant Red Galaxies (DRGs) do!massive source stacking, but Distant Red Galaxies (DRGs) do!

Defined by Defined by JJss——KKss > 2.3, which brings the Balmer break between > 2.3, which brings the Balmer break between JJss and and KKss

for for zz > 2 > 2

DRGs: massive galaxies with high SFRs; source density 3 arcminDRGs: massive galaxies with high SFRs; source density 3 arcmin–2–2

for for KK<22.5 is comparable to SMGs with >0.8 mJy at 850 <22.5 is comparable to SMGs with >0.8 mJy at 850 m (as estimatedm (as estimated from lensing from lensing surveys).surveys).

1 unlensed DRG detected directly with SCUBA (5 mJy). 1 unlensed DRG detected directly with SCUBA (5 mJy).


Rest-frame SEDs: Lyman break galaxiesRest-frame SEDs: Lyman break galaxies


Rest-frame SEDs: distant red galaxiesRest-frame SEDs: distant red galaxies


SCUBA observations of MS1054SCUBA observations of MS1054–03–03

M1383M1383SS850850 = 5 mJy = 5 mJy

(Knudsen, Van der Werf & Kneib 2007) (Toft et al., 2007; Van Starkenburg& Van der Werf, in prep.)

NICMOS ACS

5"

re = 1.26” = 10.26 kpc; H < 0.4”


Stacking DRGsStacking DRGs

DRGs, EROsDRGs, EROs

random positionsrandom positions

DRGs:DRGs:SS850850 = 1.11 = 1.11 0.28 mJy 0.28 mJy

≈≈20% of background20% of background

(Knudsen (Knudsen et al.et al., 2005), 2005)


MicrowaveBackground IR/Optical

Background

X-RayBackground

Big BangBig Bang

Stars+BlackHolesStars+BlackHoles

AGNAGN

1mm 1m 1nm

(Puget et al. 1996, Hauser et al. 1998Fixsen et al. 1998)

Cosmic backgroundsCosmic backgrounds

IRBG peaks at ≈200m.At 850m, 30 lowerAt 450m, only 3 lower


Science case 450Science case 450m surveym survey Probe the IR/submm background close to its spectral peakProbe the IR/submm background close to its spectral peak

Resolve ≈ 75% of the 450Resolve ≈ 75% of the 450m background: new territory!m background: new territory!

Out to Out to zz=3: full census of ULIRGs in survey volume=3: full census of ULIRGs in survey volume Out to Out to zz=2: full census of >3=2: full census of >310101111 LL galaxies galaxies Out to Out to zz=1: full census of >2=1: full census of >210101111 LL galaxies galaxies

Connection to other populations without stackingConnection to other populations without stacking

Deconvolve confusion-limited 850Deconvolve confusion-limited 850m mapm map

Evolution of IR/submm luminosity function,Evolution of IR/submm luminosity function, obscured star formation historyobscured star formation history


Elbaz diagramElbaz diagram

SCUBA (450m)


A2218: SCUBA 850 A2218: SCUBA 850 mm

(Kneib et al. 2005)(Kneib et al. 2005)


A2218: SCUBAA2218: SCUBA

850 850 mm 450 450 mm


A2218: deep 850 A2218: deep 850 m mapm map

(Knudsen et al. 2006)(Knudsen et al. 2006)


Deep 850Deep 850m source counts m source counts

Currently from Currently from gravitationally gravitationally lensing cluster lensing cluster fieldsfields small survey small survey volumes, affected by cosmic volumes, affected by cosmic variancevariance

Deconvolved deep 850Deconvolved deep 850m m map largemap large enough to average out enough to average out cosmic cosmic variancevariance

Several 10Several 1033 sources sources expected at >10expected at >10 down to 1.5 mJy (resolves ≈ down to 1.5 mJy (resolves ≈ 40% of 40% of 850 850 m background)m background)

((Knudsen, Van der WerfKnudsen, Van der Werf & Kneib, & Kneib, 20072007))

1010


Practical challenges at 450Practical challenges at 450mm

Even in excellent weather observing at 450Even in excellent weather observing at 450m is challenging.m is challenging.

Special care needed in calibration – monitor conditions and takeSpecial care needed in calibration – monitor conditions and take beammaps several times per nightbeammaps several times per night

Need to establish a Need to establish a rigorous observing protocolrigorous observing protocol, since the data are going, since the data are going to be taken by many different persons (often not even member of theto be taken by many different persons (often not even member of the cosmology survey team).cosmology survey team).

Surface accuracy of JCMT dish <22Surface accuracy of JCMT dish <22m is needed; m is needed; this needs to be monitored and maintainedthis needs to be monitored and maintained..

Crucial requirement for 450Crucial requirement for 450m survey depth and uniformitym survey depth and uniformity


Conclusions and outlookConclusions and outlook

850 850 m survey will produce statistically accurate results, and robustm survey will produce statistically accurate results, and robust samples for easier follow-up.samples for easier follow-up.

Clustering is a key applicationClustering is a key application

The 450The 450m survey is unique in probing lower SFRsm survey is unique in probing lower SFRs

Deep complementary data is essentialDeep complementary data is essential

Follow-up is crucial: deep radio, near-IR deployable IFUs,Follow-up is crucial: deep radio, near-IR deployable IFUs, redshift machines using COredshift machines using CO

Numbers are still “low” Numbers are still “low” a next-generation instrument? a next-generation instrument?

Documents

Der Paul van der Werf Sterrewacht Leiden The SCUBA2 Cosmology Legacy Survey - to coldly go where no man has gone before… Xining August 20, 2007