Erik D. Reese

Cosmology with the Sunyaev-Zel’dovich Effect

▪ Abstractu2002The Sunyaev-Zeldovich effect (SZE) provides a unique way to map the large-scale structure of the universe as traced by massive clusters of galaxies. As a spectral distortion of the cosmic microwave background, the SZE is insensitive to the redshift of the galaxy cluster, making it well-suited for studies of clusters at all redshifts, and especially at reasonably high redshifts (z > 1) where the abundance of clusters is critically dependent on the underlying cosmology. Recent high signal-to-noise detections of the SZE have enabled interesting constraints on the Hubble constant and on the matter density of the universe using small samples of galaxy clusters. Upcoming SZE surveys are expected to find hundreds to thousands of new galaxy clusters, with a mass selection function that is remarkably uniform with redshift. In this review we provide an overview of the SZE and its use for cosmological studies, with emphasis on the cosmology that can, in principle, be extracted from SZE survey yields. We ...

Determining the Cosmic Distance Scale from Interferometric Measurements of the Sunyaev-Zeldovich Effect

We determine the distances to 18 galaxy clusters with redshifts ranging from z ~ 0.14 to 0.78 from a maximum likelihood joint analysis of 30 GHz interferometric Sunyaev-Zeldovich effect (SZE) and X-ray observations. We model the intracluster medium (ICM) using a spherical isothermal β model. We quantify the statistical and systematic uncertainties inherent to these direct distance measurements, and we determine constraints on the Hubble parameter for three different cosmologies. These distances imply a Hubble constant of 60 km s-1 Mpc-1 for an ΩM = 0.3, ΩΛ = 0.7 cosmology, where the uncertainties correspond to statistical followed by systematic at 68% confidence. With a sample of 18 clusters, systematic uncertainties clearly dominate. The systematics are observationally approachable and will be addressed in the coming years through the current generation of X-ray satellites (Chandra and XMM-Newton) and radio observatories (Owens Valley Radio Observatory, Berkeley-Illinois-Maryland Association, and Very Large Array). Analysis of high-redshift clusters detected in future SZE and X-ray surveys will allow a determination of the geometry of the universe from SZE-determined distances.

Galaxy Cluster Gas Mass Fractions from Sunyaev-Zeldovich Effect Measurements: Constraints on ΩM

Using sensitive centimeter-wave receivers mounted on the Owens Valley Radio Observatory and Berkeley-Illinois-Maryland-Association millimeter arrays, we have obtained interferometric measurements of the Sunyaev-Zeldovich (SZ) effect toward massive galaxy clusters. We use the SZ data to determine the pressure distribution of the cluster gas and, in combination with published X-ray temperatures, to infer the gas mass and total gravitational mass of 18 clusters. The gas mass fraction, fg, is calculated for each cluster and is extrapolated to the fiducial radius r500 using the results of numerical simulations. The mean fg within r500 is 0.081 h (statistical uncertainty at 68% confidence level, assuming ΩM = 0.3, ΩΛ = 0.7). We discuss possible sources of systematic errors in the mean fg measurement. We derive an upper limit for ΩM from this sample under the assumption that the mass composition of clusters within r500 reflects the universal mass composition: ΩMh ≤ ΩB/fg. The gas mass fractions depend on cosmology through the angular diameter distance and the r500 correction factors. For a flat universe (ΩΛ ≡ 1 - ΩM) and h = 0.7, we find the measured gas mass fractions are consistent with ΩM < 0.40, at 68% confidence. Including estimates of the baryons contained in galaxies and the baryons which failed to become bound during the cluster formation process, we find ΩM ~ 0.25.

Detection of the Cosmic Infrared Background at 2.2 and 3.5 Microns Using DIRBE Observations

We compare data from the Diffuse Infrared Background Experiment (DIRBE) on COBE to the model of the infrared sky provided by Wainscoat and colleagues in 1992. The model is first compared with broadband K (2.2 ?m) star counts. Its success at K band lends credence to its physical approach, which is extrapolated to the L band (3.5 ?m). We have analyzed the histograms of the pixel-by-pixel intensities in the 2.2 and 3.5 ?m maps from DIRBE after subtracting the zodiacal light. The shape of these histograms agrees quite well with the histogram shape predicted using the Wainscoat model of the infrared sky, but the predicted histograms must be displaced by a constant intensity in order to match the data. This shift is the cosmic infrared background, which is 16.9 ? 4.4 kJy sr-1 or 23.1 ? 5.9 nW m-2 sr-1 at 2.2 ?m and 14.4 ? 3.7 kJy sr-1 or 12.4 ? 3.2 nW m-2 sr-1 at 3.5 ?m. Combining our near-IR results with the far-IR background detected by Hauser and colleagues in 1998 suggests that roughly half of the radiation produced by galaxies is absorbed by dust and reradiated in the far-IR.

Sunyaev-Zeldovich Effect-derived Distances to the High-Redshift Clusters MS 0451.6–0305 and Cl 0016+16

We determine the distances to the z~0.55 galaxy clusters MS 0451.6-0305 and CL 0016+16 from a maximum likelihood joint fit to interferometric Sunyaev-Zeldovich effect (SZE) and X-ray observations. We model the intracluster medium (ICM) using a spherical isothermal beta-model. We quantify the statistical and systematic uncertainties inherent to these direct distance measurements, and we determine constraints on the Hubble parameter for three different cosmologies. For an OmegaM = 0.3, OmegaL = 0.7 cosmology, these distances imply a Hubble constant of 63 ^{+12}_{- 9} ^{+21}_{-21} km/s/Mpc, where the uncertainties correspond to statistical followed by systematic at 68% confidence. The best fit Ho is 57 km/sec/Mpc for an open OmegaM = 0.3 universe and 52 km/s/Mpc for a flat Omega = 1 universe.We determine the distances to the z approximately equals 0.55 galaxy clusters MS 0451.6 - 0305 and Cl 0016 + 16 from a maximum-likelihood joint fit to interferometric Sunyaev-Zeldovich effect (SZE) and X-ray observations. We model the intracluster medium (ICM) using a spherical isothermal beta model. We quantify the statistical and systematic uncertainties inherent to these direct distance measurements, and we determine constraints on the Hubble parameter for three different cosmologies. For an Omega(sub M) = 0.3, Omega(sub lambda) = 0.7 cosmology, these distances imply a Hubble constant of 63(sup +12) (sub -9) (sup + 21) (sub -21) km/s Mp/c, where the uncertainties correspond to statistical followed by systematic at 68% confidence. The best-fit H(sub 0) is 57 km/s Mp/c for an open (Omega(sub M) = 0.3) universe and 52 km/s Mp/c for a flat (Omega(sub M) = 1) universe.

Sunyaev-Zeldovich Effect Imaging of Massive Clusters of Galaxies at Redshift z > 0.8

We present Sunyaev-Zeldovich effect (SZE) imaging observations of three distant (z > 0.8) and highly X-ray luminous clusters of galaxies, Cl J1226.9+3332, Cl J0152.7-1357, and MS 1054.4-0321. Two of the clusters, Cl J1226.9+3332 and Cl J0152.7-1357, were recently discovered in deep ROSAT X-ray images. Their high X-ray luminosity suggests that they are massive systems, which, if confirmed, would provide strong constraints on the cosmological parameters of structure formation models. Our SZE data provide confirmation that they are massive clusters similar to the well-studied cluster MS 1054.4-0321. Assuming the clusters have the same gas mass fraction as that derived from SZE measurements of 18 known massive clusters, we are able to infer their mass and electron temperature from the SZE data. The derived electron temperatures are 9.8, 8.7, and 10.4 keV, respectively, and we infer total masses of ~2 × 1014 h M☉ within a radius of 65 (340 h kpc) for all three clusters. For Cl J0152.7-1357 and MS 1054.4-0321, we find good agreement between our SZE-derived temperatures and those inferred from X-ray spectroscopy. No X-ray-derived temperatures are available for Cl J1226.9+3332, and thus the SZE data provide the first confirmation that it is indeed a massive system. The demonstrated ability to determine cluster temperatures and masses from SZE observations without access to X-ray data illustrates the power of using deep SZE surveys to probe the distant universe.

The Sunyaev-Zeldovich Effect in Abell 370

We present interferometric measurements of the Sunyaev-Zeldovich (SZ) eUect toward the galaxy cluster Abell 370. These measurements, which directly probe the pressure of the clusters gas, show the gas distribution to be strongly aspherical, as do the X-ray and gravitational lensing observations. We calculate the clusters gas mass fraction in two ways. We —rst compare the gas mass derived from the SZ measurements to the lensing-derived gravitational mass near the critical lensing radius. We also calculate the gas mass fraction from the SZ data by deprojecting the three-dimensional gas density distribution and deriving the total mass under the assumption that the gas is in hydrostatic equilibrium (HSE). We test the assumptions in the HSE method by comparing the total cluster mass implied by the two methods and —nd that they agree within the errors of the measurement. We discuss the possible system- atic errors in the gas mass fraction measurement and the constraints it places on the matter density parameter, ) M. Subject headings: cosmic microwave backgroundcosmology: observations ¨ galaxies: clusters: individual (Abell 370) ¨ techniques: interferometric

SUNYAEV-ZELDOVICH EFFECT IMAGING OF MACS GALAXY CLUSTERS AT z >0 .5

We present 30 GHz interferometric Sunyaev-Zeldovich effect (SZE) measurements of a redshift-limited, X-ray–selected cluster sample from the Massive Cluster Survey (MACS). All eight of the high-redshift (z > 0:5, �> � 15 � ) galaxy clusters were detected. Additional observations were made at 4.8 GHz with the Very Large Array to help constrain the amount of point source contamination to the SZE decrements. From SZE data alone, we derive electron temperatures in the range 5.5–18.5 keV and total masses between 1.5 and

Imaging the sunyaev-zel'dovich effect

We report on results of interferometric imaging of the Sunyaev–Zeldovich Effect (SZE) with the OVRO and BIMA mm-arrays. Using low-noise cm-wave receivers on the arrays, we have obtained high quality images for 27 distant galaxy clusters. We review the use of the SZE as a cosmological tool. Gas mass fractions derived from the SZE data are given for 18 of the clusters, as well as the implied constraint on the matter density of the universe, ΩM. We find ΩMh100 ≤ 0.22+0.05-0.03. A best guess for the matter density obtained by assuming a reasonable value for the Hubble constant and also by attempting to account for the baryons contained in the galaxies as well as those lost during the cluster formation process gives ΩM ~ 0.25. We also give preliminary results for the Hubble constant. Lastly, the power for investigating the high redshift universe with a non-targeted high sensitivity SZE survey is discussed and an interferometric survey is proposed.

THE X-RAY SIZE-TEMPERATURE RELATION FOR INTERMEDIATE REDSHIFT GALAXY CLUSTERS

We present the first measurements of the X-ray size-temperature (ST) relation in intermediate-redshift (z ~ 0.30) galaxy clusters. We interpret the local ST relation (z ~ 0.06) in terms of underlying scaling relations in the cluster dark matter properties, and then we use standard models for the redshift evolution of those dark matter properties to argue that the ST relation does not evolve with redshift. We then use ROSAT HRI observations of 11 clusters to examine the intermediate-redshift ST relation; for currently favored cosmological parameters, the intermediate-redshift ST relation is consistent with that of local clusters. Finally, we use the ST relation and our evolution model to measure angular diameter distances; with these 11 distances we evaluate constraints on ΩM and ΩΛ that are consistent with those derived from studies of Type Ia supernovae. The data rule out a model with ΩM = 1 and ΩΛ = 0 with 2.5 σ confidence. When limited to models where ΩM + ΩΛ = 1, these data are inconsistent with ΩM = 1 with 3 σ confidence.