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

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

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)

Zoom in on 2 mm map ~ 4 deg 2 of actual data

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

Detecting the SZ Power Spectrum SPT Measured Points (model + Gaussian scatter) 10  K-arcmin point sources Hall et al. (2009, arxiv: ): we report tSZ + kSZ + clustered point-source power of 10  K 2 at =150GHz and l=3000 primary CMB 150GHz What happened to all the thermal SZ power?

Clustering of Point Sources Radio and IR/submm sources presumably trace the large scale matter fluctuations Back of the envelope: –Power spectrum contribution: mean T 2 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

The importance of multiple frequencies

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

10 First detection of clustered point source power from CIB sources in the mm bands Hall et al 2010 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)

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 T x T 220 –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

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

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

Power Spectrum: Dusty Galaxy Contributions Subtracted Best fit 150 GHz power: tSZ+0.46*kSZ=4.2  1.5 uK 2 tSZ kSZ

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

Not Much Room for kSZ Thermal SZ alone is already a bit low Using X-ray-based profiles and WMAP chains, c l   8 16 covariances between parameters conspire, in particular , h SPT analysis (Lueker et al.) used semi- analytic gas model, with c l  8 11 in CMB chains Best fit 150 GHz power: tSZ+0.46*kSZ=4.2 ±1.5 uK2

Where does SZ Power Come From? Broad range in z Extends to low mass (relative to SPT SZ- detected clusters) From Shaw et al 09 Rough SPT mass limit for detection Non-Gaussianity of statistics d 2 c l /(dlnM dz) at ell~2500

SPT Galaxies at 150 & 220 GHz

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

AGN counts AGN counts as predicted

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

dust source counts red = Lagache blue = Pearson

BCS image of a dusty SPT source with an IRAS counterpart r band 5σ = AB mag i band 5σ = AB mag S 1.4 = 14 mJy S 2.0 = 8 mJy

BCS image of a dusty SPT source without any counterpart r band 5σ = AB mag i band 5σ = AB mag S 1.4 = 17 mJy S 2.0 = 5 mJy

dust source counts WITH IRAS SOURCES REMOVED red = Lagache blue = Pearson

Comparison to Negrello et al. 2007

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: 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

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

SMG 10 S 1.4mm =21 mJy SPT,SMA,IRAC,Gemini

SMG 03 S 1.4mm =37 mJy BCS

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)

IR/Submm Source Clustering Mean T cmb ~10 4 uK at 500 um (FIRAS) Clustering amplitude => few 10 5 uK2 BLAST: 10 6 uK 2 Mean T cmb ~50 uK at 150 GHz (FIRAS, number counts) => few uK 2 We do actually have a clustering model BLAST: Viero et al 2009

Extrapolate ARCADE results to 150 GHz: 5uK Extrapolate source models: less than 1 uK –=> << 1uK 2 clustering power at 150 GHz Aside: ARCADE extrapolation to 30 GHz: T~200 uK 30 GHz clustering power could be >50 uK 2 However: widely agree that ARCADE results are hard to reconcile with known populations Radio Source Clustering Fixsen et al 2009