ObservingObserving thethe SunyaevSunyaev--ZelZel’’dovichdovich EffectEffect

MattMatt DobbsDobbs McGill University TheThe SunyaevSunyaev--ZelZel’’dovichdovich EffectEffect

CMB photons are used to backlight structure in the universe.

(slide adapted from NASA publicity figure) [email protected], December 5, 2007 2 GalaxyGalaxy ClustersClusters Abell 1689

„ Largest gravitationally collapsed structures Ælargest clusters derived from scales that are almost linear Ætheir history traces out interplay between dark energy and matter through cosmic time.

„ ICM: Hot diffuse plasma is bulk of cluster mass z Easily seen in SZ and x-ray 7 8 z Te ≈ 10 keV ≈ 10 -10 K

„ Cluster abundance and evolution are critically dependent on cosmology. z Growth based dark energy test (complement to distance based SN tests) Chandra x-ray image of cluster

[email protected], December 5, 2007 3 TheThe SunyaevSunyaev--ZelZel’’dovichdovich EffectEffect

BIMA

SuZIE Diabolo

FREQUENCY FREQUENCY „ 1-2% of CMB photons traversing galaxy clusters are inverse Compton scattered to higher energy.

[email protected], December 5, 2007 4 GalaxyGalaxy clustercluster searchessearches

Carlstrom et al., (BIMA)

„ SZSZ observationsobservations dodo notnot fadefade awayaway overover largelarge distances.distances. „ UnbiasedUnbiased tooltool forfor selectingselecting clusters.clusters.

[email protected], December 5, 2007 5 SunyaevSunyaev--ZelZel’’dovichdovich EffectEffect

SingleSingle ClustersClusters ΔTSZ ∝ neTedl z Measure of integrated pressure T ∫ (total thermal energy) CMB z Peculiar velocities at high z 1 2 S X = 4 ne Λeedl z Distances, Ho, H(z) 4π ()1+ z ∫ z Cluster gas mass fractions, structure, etc. (compare to x-ray surface brightness)

ClusterCluster SurveysSurveys z Exploit SZ redshift independence S ∝ ΔT dΩ ∫ SZE z Measure growth of structure 1 z constrain Dark Energy ∝ n T dV 2 ∫ e e DA (z)

[email protected], December 5, 2007 6 SZSZ CosmologyCosmology ExampleExample Number count vs. redshift is very sensitive to dark energy and total matter distribution.

Simulation by M. White 10 sq. degree

Projections for 4000 sq deg SPT by Gil Holder Assuming (optimistic!) σ8=0.9 [email protected], December 5, 2007 7 SZ/CMBSZ/CMB PowerPower SpectrumSpectrum

Readhead et al. ApJ. 609 (2004)

7 Cl(SZ) ∝σ8 e.g., Komatsu & Seljak astro-ph/0205468 [email protected], December 5, 2007 8 SZSZ forfor CartographyCartography

„ CircaCirca 19951995--20052005 experimentsexperiments useuse ≤≤dozensdozens ofof detectorsdetectors „ CapableCapable ofof pointedpointed observationsobservations atat knownknown clustersclusters

„ SZSZ ForteForte isis (relatively)(relatively) unbiasedunbiased selectionselection functionfunction-- ÆÆ BlindBlind clustercluster surveyssurveys requirerequire anan orderorder ofof magnitudemagnitude increaseincrease inin sensitivity,sensitivity, oror factorfactor 100100 inin detectors.detectors.

[email protected], December 5, 2007 9 (ground(ground based)based) SZSZ InstrumentsInstruments Existing/Past:Existing/Past: „ Interferometers:Interferometers: Ryle,Ryle, OVRO/BIMA,OVRO/BIMA, CBICBI (I,II),(I,II), VSA,VSA, AmibaAmiba „ SingleSingle dishdish radio:radio: OVROOVRO 40m,40m, OVROOVRO 5m,5m, NobeyamaNobeyama 45m45m,, OCRAOCRA „ SingleSingle dishdish bolometers:bolometers: SuZIESuZIE (I,II,II)(I,II,II) andand BolocamBolocam onon CSOCSO 10m,10m, DiaboloDiabolo onon IRAMIRAM 30m,30m, SESTSEST 15m,15m, SCUBASCUBA onon JCMTJCMT 15m,15m, MITOMITO 2.62.6 m,m, ACBAR, ASTE 10m, MUSTANG on NRAO GBT 100 m

NewNew DedicatedDedicated SZSZ InstrumentsInstruments z Arcminute Microkelvin Imager (15 GHz, ten 3.6m interferometer) z The Sunyaev Zel’dovich Array (30,90 GHz, eight 3.5m interferometer) z APEX-SZ (12m, 320 pixel) z The South Pole Telescope (10m, 1000 pixel) z Atacama Cosmology Telescope (6m, 3000 pixel)

[email protected], December 5, 2007 10 Owen’s Valley Radio Observatory BIMABIMA // OVROOVRO „ ImagingImaging ofof knownknown clustersclusters z >> 6060 SZSZ clustersclusters observedobserved z correlationcorrelation withwith ChandraChandra xx-- rayray forfor 3838 clustersclusters

Color: Chandra x-ray Radial profile of x-ray surface brightness Radial profile of x-ray plasma temperatures Contours: SZ S/N from BIMA Line: best double-β model fit. Line: best fit hydrostatic equil. model

FWHM of the SZE synthesized beam

Bonamente (BIMA +Chandra), ApJ 647 (2006) 25. [email protected], December 5, 2007 11 HubbleHubble DiagramDiagram fromfrom SZSZ ++ XX--rayray

„ ΔΔTTSZ fromfrom 3838 OVRO/BIMAOVRO/BIMA Clusters,Clusters, 0.14

„ SSX,, TTe fromfrom ChandraChandra XX--rayray datadata -1 -1 „ H0=76.9 ±4 ±9 km s Mpc (assumes ΛCDM) z Relatively insensitive to cluster radial profile model (+- 3)

z Weakly sensitive of ΩM, ΩΛ. „ Agrees well with nearby universe measurements from Hubble Key Project. Bonamente et. al., ApJ 647 (2006) 25.

2 ΔT CMBΛee DA ∝ 2 S X Te

Udompraset et al. (CBI), 2004 (not used in fit)

[email protected], December 5, 2007 12 GasGas MassMass FractionsFractions fromfrom BIMA/OVROBIMA/OVRO

„ DerivedDerived fromfrom 3838 clusters,clusters, 0.140.14 << zz << 0.890.89 „ SignificantSignificant scatter,scatter, butbut nono evidenceevidence forfor redshiftredshift trend.trend. z Triangles=cool-core clusters, squares=noncool-core clusters „ (assumes(assumes ΛΛCDM)CDM)

LaRoque et al. (BIMA/OVRO), Astro J. 652 (2006) 917.

s

a

s

g

a

f

g f

[email protected], December 5, 2007 13 SZASZA atat OwensOwens ValleyValley U.Chicago/KICP, Caltech, Columbia, NASA/MSFC „ EightEight 3.5m3.5m telescopestelescopes „ 3030 && 9090 GHzGHz z X-ray selected cluster obs z 6 sq degree blind survey

„ 20082008 CARMACARMA 2323-- elementelement array:array: MergeMerge BIMABIMA ++ OVROOVRO ++ SZASZA z Detailed SZ imaging First SZA images Muchovej et. al., ApJ 663 (2007) 708 (astro-ph:0610115).

z = 0.17 z = 0.17 z = 0.69 [email protected] = 0.89, December z = 1.03 5, 2007 14 Test of SZA survey on Cl0016+0016

• 10 pointing SZA mosaic • 4.8 arcminute separation • Median rms 0.31mJy/beam • Bright radio source at > 60 sigma

Two Clusters Detected

Cl0016+0016 M ~ 1.3 x 10^15 M_solar (Hughes et al., 1995, ApJ448:L93)

RXJ0018.3+1618 M ~ 5 x 10^14 M_solar (Hughes & Birkinshaw, 1998, ApJ 497:645)

Loh et. al, in prep [email protected], December 5, 2007 15 SZASZA HighHigh--zz ClustersClusters

„ Above: x-ray in color, SZ contours „ Right: same cluster fields, before removing point sources −α ⎛ ν ⎞ ⎜ ⎟ I31GHz ⎜ ⎟ ⎝ 31GHz ⎠

Spectral index from Muchovej et. al. (SZA), Astro J., 663 (2007) 708. SZA bands alone [email protected], December 5, 2007 17 SZASZA blindblind SZSZ--surveysurvey

• ~ 6 square degrees complete (Muchovej in prep, Ph.D. Thesis) • radio source contamination is big issue at 30 GHz • both point like and extended sources present • SZA has 90 GHz follow-up, 5 & 8 GHz from VLA.

[email protected], December 5, 2007 18 EnablingEnabling TechnologyTechnology forfor SZSZ SurveysSurveys

„ ““bigbig”” bolometerbolometer arraysarrays „ readoutreadout multiplexingmultiplexing „ coolingcooling withoutwithout expendableexpendable cryogenscryogens CoherentCoherent AmplificationAmplification vs.vs. BolometersBolometers

Bolometers Projected Sensitivity 2010 HEMT s ] √ K μ 250

200 mit se Li 150 Noi ntum Qua 100

S ensitivity [ 50

0 30 40 60 90 120 150 220 350 Frequency [ GHz ]

Source: Weiss DOE/NSF/NASA CMB Taskforce, Table 7.2 [email protected], December 5, 2007 20 TransitionTransition EdgeEdge SensorSensor BolometerBolometer

Incident Radiation

Thermometer Absorber C Tbolo=Tbath+ P/G

G Thermal Conductivity Voltage biased in electro- thermal feedback Thermal Bath Tbath

Al

These detectors fabricated at UC Berkeley by Erik Shirokoff, Sherry Cho, Jared Mehl 4 mm Ti

[email protected], December 5, 2007 21 Example:Example: SPTSPT BolometerBolometer ArrayArray

180 mm; ~1 degree on sky Built at UC Berkeley

150 GHz 1 z 5 0

GH G H 0 9 z

1 5 z 0 5” H G G Apex-SZH proto 0 z 9 220 GHz

• 160 possible channels on each wedge, 8x multiplex “Spiderweb” • Transition Edge Sensor bolometers with Tc ~500mK Bolometers

Al/Ti TES ACTACT MBACMBAC ArrayArray

Niemack et al., to appear in J. Low Temp. Phys. „ 3232 xx 3232 arrayarray ofof GoddardGoddard ““poppop-- upup”” bolometersbolometers „ CloseClose packedpacked

[email protected], December 5, 2007 23 ReadoutReadout MultiplexingMultiplexing SQUID Output Time-domain multiplexer NIST / UBC for ACT, (Clover, Spider, SCUBA-II, etc.) SQUID Output

Frequency-domain multiplexer Pulse Height LBNL / Berkeley / McGill for APEX, SPT, (EBEX, …) time ReadoutReadout MultiplexingMultiplexing

Time-domain multiplexer NIST / UBC for ACT, (Clover, Spider, SCUBA-II, etc.)

Frequency-domain multiplexer LBNL/Berkeley/McGill for APEX, SPT, (EBEX, …) CoolingCooling withoutwithout ExpendableExpendable CryogensCryogens

„ MechanicalMechanical coolingcooling forfor bolometerbolometer experimentsexperiments isis challengingchallenging z microphonic pickup (vibrations) z moving parts at 4K

„ NewNew generationgeneration ofof experimentsexperiments usingusing PulsePulse TubeTube CoolersCoolers z Piston in cold head is a shock-wave of helium gas

„ EliminatesEliminates needneed forfor cryogens,cryogens, allowingallowing experimentsexperiments toto runrun longlong termterm atat remoteremote locations.locations. APEX-SZ Camera is shown z (APEX, SPT, ACT all use PTCs) mounted in cabin with pulse tube lines & ballasts visible. [email protected], December 5, 2007 27 [email protected], December 5, 2007 28 AAPEXPEX--SZSZ U.C. Berkeley/LBNL, Max Planck IfR, Bonn, Boulder, Cardiff, McGill

„ 12m ALMA prototype „ 1’ resolution

„ 320 bolometer array „ 150 GHz TES „ Frequency multiplexed readout

„ pulse tube cooler w/ 3He sorption fridge „ First light, Dec 2005 APEXAPEX--SZSZ BeamsBeams „ Mapping mars, without applying pixel offsets „ Typically ~260/320 pixels active

[email protected], December 5, 2007 30 APEXAPEX--SZSZ ClusterCluster ImageImage ExamplesExamples

„ Chandra x-ray surface brightness superimposed

BulletBullet ClusterCluster

AbellAbell 34043404

[email protected], December 5, 2007 31 AtacamaAtacama CosmologyCosmology TelescopeTelescope

[email protected], December 5, 2007 33 AtacamaAtacama CosmologyCosmology TelescopeTelescope (ACT)(ACT)

„ 6m off-axis dish „ 3000 bolometers: 145, 220, 265 GHz fabbed at Goddard „ 1.7 arcminute resolution „ Deploying near ALMA site „ 1st light achieved June 2007 with 32 detector CCAM prototype receiver. „ (new!) MBAC 1024 pixel camera 1st Light – Jupiter operating now at 145 GHz With 32 pixel CCAM (typically 900 detectors live) „ Plan to install 3 color (145,220, 265 GHz) in May 2008.

Cardiff Columbia CUNY Drexel Haverford NASA/GSFC UMASS PennPrinceton Rutgers Univ. de Catolica [email protected], December 5, 2007 34 TheThe SouthSouth PolePole TelescopeTelescope

Last flight out - australPhoto Credit Summer Steffen 07/08 Richter

[email protected], December 5, 2007 35 TheThe SouthSouth PolePole TelescopeTelescope

• 960 TES Bolometers • frequency multiplexed readout • pulse tube cooler • 90, 150, 220 GHz bands • 1 arcmin resolution at 2mm

•20 μmRMS surface over 10m • cold (10 K) secondary mirror • 1 degree FOV, 1’’ pointing

SZE and CMB Anisotropy • 4000 sq deg SZE survey • deep CMB anisotropy fields • deep CMB Polarization fields

First light achieved Feb 16, 2007 [email protected], December 5, 2007 36 Deployment:Deployment: NovNov 0606 -- FebFeb 0707

[email protected], December 5, 2007 37 SPTSPT OpticsOptics andand radiometerradiometer

250mK

10K

[email protected], December 5, 2007 38 FirstFirst LightLight andand TestTest ObservationsObservations

First light with scans across Jupiter, Feb. 16 2007!

Scanning across Mars, without correcting for pixel offsets

~400 detectors working on first days.

[email protected], December 5, 2007 39 SPT: First Cluster Observation (AS1063) April 7, 2007

(Combined 90 and 150 GHz detectors)

[email protected], December 5, 2007 40 BeginningBeginning ofof SPTSPT SurveySurvey –– BCSBCS FieldField

Co-added 150 GHz Maps, smoothed to 2’

SUM DIFFERENCE

[email protected], December 5, 2007 41 ChallengesChallenges forfor SZSZ CartographyCartography

(just(just aa twotwo examplesexamples……)) ScalingScaling RelationsRelations „ KeyKey challengechallenge forfor SZSZ surveyssurveys –– howhow toto relaterelate observationsobservations

(Y(YSZ)) toto aa quantityquantity thatthat isis wellwell predictedpredicted byby theorytheory (e.g.(e.g. totaltotal clustercluster mass)mass) z If gravitational processes dominate cluster evolution, aa selfself-similar scaling gives a simple relation

2 5/3 2/3 YSZ DA ∝ f gas M TOT E(z) Bonamente et al. (BIMA), astro-ph/0708.0815 z Numerical sim Æ on large

scales, YSZ should be a good proxy for MTOTAL. -2/3 z Agrees best with simulations

that include radiative cooling, E(z) A

star formation, and feedback. 2 SLOPE z Shaw et al., astro-ph 0710.4555 Simple Model 1.66 Y D reduce scatter by e.g. using All Clusters 1.66±.20

Y(R500) to infer MTOT(R200) 0.14

2 3 2 MTOT E (z) = ΩM (1+ z) + ΩΛ + Ωk (1+ z) [email protected], December 5, 2007 44 ScalingScaling RelationsRelations

2 5/ 2 −1 YSZ DA ∝ f gasTe E(z)

Bonamente et al. (BIMA), astro-ph/0708.0815 E(z) A 2 SLOPE Simple Model 2.5 Y D All Clusters 2.37±0.23 0.14

kTe(keV)

[email protected], December 5, 2007 45 RadioRadio PointPoint SourceSource ContaminationContamination

„ CorrelatedCorrelated withwith clusters,clusters, obscuringobscuring signal.signal. „ IfIf youyou justjust extrapolateextrapolate thethe knownknown 3030 GHzGHz sourcessources toto 150150 withwith thethe samesame frequencyfrequency relation,relation, youyou’’rere inin trouble.trouble. z But typically there’s a break point. A piece of the 30 GHz sky from SZA (from Muchovej in prep, Ph.D. Thesis) Tools:Tools: „ SZASZA 3030 ++ 9090 GHzGHz „ FirstFirst 150150 GHzGHz mapsmaps expectedexpected soonsoon fromfrom APEX,APEX, SPT,SPT, ACTACT z Combine with existing radio surveys

A (much bigger) piece of the 150 GHz sky from SPT [email protected], December 5, 2007 46 SummarySummary

„ SZ – redshift independent cluster observations z Samples of several dozen clusters (e.g. BIMA, SZA) z Consistent picture emerging from x-ray / SZ

„ Cluster surveys exploit the redshift independence to measure the growth of structure through cosmic time. z Enabling technology: large bolometer array cameras z Next generation experiments (e.g. ACT, SPT) have begun operations and producing first images. ¾ First Light Feb ’07 (SPT), May ’07 (ACT) z Stay tuned …

„ Still some challenges to conquer z Does radio spectrum ‘break’ soon enough?

z Scaling relations and ‘calibration’ of the YSZ – MTOT relation. ¾ SZ imagine machines such as SZA will have a lot to say on this in next year.

[email protected], December 5, 2007 47