Galaxies and galaxy clusters at mm wavelengths: the view from the South Pole Telescope

1. Galaxies and galaxy clusters at mm wavelengths: the view from the South Pole Telescope Gil Holder

2. On one side: CMB/SZ, “fundamental physics” on the other side: BLAST, “astrophysics”

3. Outline • Small scale CMB anisotropy • Detection of secondary anisotropies • Limits on thermal SZ, kinetic SZ Lueker et al, Hall et al (both submitted) • Galaxies • “point sources” in SPT maps • Dusty and/or synchroton-dominated galaxies • a new class of dusty galaxies? Vieira et al (submitted)

4. Zoom in on 2 mm map ~ 4 deg2 of actual data

5. Detecting the SZ Power Spectrum • after removing bright sources, there is still small-scale contamination from residual sources • Primary CMB looks right • Poisson Point-sources as expected 150GHz SPT Measured Points (model + Gaussian scatter) primary CMB 10 K-arcmin point sources guess at SZ power spectrum (8=0.8)

6. Detecting the SZ Power Spectrum 150GHz Hall et al. (2009, arxiv:0912.4315): we report tSZ + kSZ + clustered point-source power of 10K2 at =150GHz and l=3000 SPT Measured Points (model + Gaussian scatter) primary CMB 10 K-arcmin point sources What happened to all the thermal SZ power?

7. Clustering of Point Sources • Radio and IR/submm sources presumably trace the large scale matter fluctuations • Back of the envelope: • Power spectrum contribution: mean T2 x projected clustering amplitude • Arcminute scales: few Mpc has clustering ~1 in 3D, divide by number of independent cells along line of sight => 1e-3

8. The importance of multiple frequencies

9. Frequency scaling of Dusty Galaxy Background 9 Scaling of Poisson power with frequency Hall et al 2010

10. Frequency scaling of Dusty Galaxy Backgrounds Single-SED model assumes all galaxies have same rest-frame properties (T=34 K, =2) spread over a broad range in redshift (peaking at z=2) First detection of clustered point source power from CIB sources in the mm bands 10 Hall et al 2010

11. Removing dusty galaxies • Models suggest that nearly all of the residual power (both Poisson and clustered) is from high-z dusty galaxies • To remove these, SPT constructed a map that is T150-xT220 • Subtraction factor is tuned to minimize small scale power [no noise bias in power spectrum] • New map has all of tSZ, but has subtracted some fraction of CMB+kSZ • Subtraction is imperfect: unknown and non-unique spectral behaviour of dusty sources

12. Temperature scaling • Radio sources look a lot like CMB • Dusty galaxies are much brighter at higher frequencies Dusty galaxies (z=0,2,5) dTcmb Radio galaxies Frequency (GHz)

13. Power Spectrum: Dusty Galaxy Contributions Largely Subtracted Direct subtraction of (220 GHz map)/3 from 150 GHz map to remove dusty galaxies

14. Power Spectrum: Dusty Galaxy Contributions Subtracted Best fit 150 GHz power: tSZ+0.46*kSZ=4.2 1.5 uK2 tSZ kSZ

15. What does the low SZ power mean? • If we assume the fiducial tSZ model is correct (and some fiducial kSZ template), we find 8 = 0.746 ± 0.017 • Compare to 8 = 0.794 ± 0.027 for WMAP5 + ACBAR + QUaD • Allowing the best estimate (from theory considerations) 50% uncertainty on tSZ model amplitude gives 8 = 0.779 ± 0.025

16. Not Much Room for kSZ • Thermal SZ alone is already a bit low • Using X-ray-based profiles and WMAP chains, cl 816 • covariances between parameters conspire, in particular , h • SPT analysis (Lueker et al.) used semi-analytic gas model, with cl 811 in CMB chains Best fit 150 GHz power: tSZ+0.46*kSZ=4.2 ±1.5 uK2

17. Where does SZ Power Come From? d2cl /(dlnM dz) at ell~2500 Rough SPT mass limit for detection • Broad range in z • Extends to low mass (relative to SPT SZ-detected clusters) Non-Gaussianity of statistics From Shaw et al 09

18. SPT Galaxies at 150 & 220 GHz

19. Distribution of Spectral Indices sources cleanly separate into two populations synchrotron dust

20. AGN counts AGN counts as predicted

21. 150 GHz at high flux source counts dominated by synchrotron-dominated sources at the low flux end of the 1.4 mm band where dusty sources become dominant 220 GHz

23. dust source counts red = Lagache blue = Pearson

24. BCS image of a dusty SPT source with an IRAS counterpart S1.4 = 14 mJy S2.0 = 8 mJy r band 5σ = 24.65 AB mag i band 5σ = 24.35 AB mag

25. BCS image of a dusty SPT source without any counterpart S1.4 = 17 mJy S2.0 = 5 mJy r band 5σ = 24.65 AB mag i band 5σ = 24.35 AB mag

26. dust source countsWITH IRAS SOURCES REMOVED red = Lagache blue = Pearson

27. Comparison to Negrello et al. 2007

29. Current Followup Campaign • ATCA: 3 mm 4 detections after two weeks of observing • SMA: 1.4 mm detections for ~ 10 or our most northern sources • Spitzer: 3.6 + 4.5 um observations down to 1 uJy (data taken, fully reduced) • NOAO SOAR 4m: R,I,J,K observations done, data being reduced • Gemini-S: spectroscopy for z>4 candidates in queue • BCS griz ~ 60 square degrees in the can

30. Interferometric Follow-up • ATCA at 90 GHz • Hard frequency • Good location (Australia) • SMA at 220 GHz • Easy frequency • Terrible location (Mauna Kea)

31. SMG 10 S1.4mm=21 mJy SPT,SMA,IRAC,Gemini

32. SMG 03 S1.4mm=37 mJy BCS

33. Summary • SPT has measured the small-scale CMB power spectrum, detecting secondaries • SZ power may be a bit low (or matter power spectrum is a bit low) Hall et al, Lueker et al (submitted) • interesting population of galaxies at mm wavelengths • Either nearby galaxies with very cold dust or extremely bright high-z galaxies • Lensed? • Discovered because of large area (~100 deg^2) searched compared to existing catalogs Vieira et al (submitted)

34. IR/Submm Source Clustering • Mean Tcmb~104 uK at 500 um (FIRAS) • Clustering amplitude 10-3 • => few 105 uK2 • BLAST: 106 uK2 • Mean Tcmb~50 uK at 150 GHz (FIRAS, number counts) • => few uK2 • We do actually have a clustering model BLAST: Viero et al 2009

35. Radio Source Clustering • Extrapolate ARCADE results to 150 GHz: 5uK • Extrapolate source models: less than 1 uK • => << 1uK2 clustering power at 150 GHz • Aside: ARCADE extrapolation to 30 GHz: T~200 uK • 30 GHz clustering power could be >50 uK2 • However: widely agree that ARCADE results are hard to reconcile with known populations Fixsen et al 2009