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 S = n 2Λ dl X 4 ∫ e ee 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<z<0.890.14<z<0.89 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 250 s ] 200 √ K μ 150 mit se Li Noi ntum 100 Qua 50 S ensitivity [ 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