IMPACT OF CLUSTER PHYSICS ON THE SUNYAEV-ZEL'DOVICH POWER SPECTRUM

Journal Article · Mon Dec 20 00:00:00 EST 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/725/2/1452· OSTI ID:21476710

Shaw, Laurie D; Nagai, Daisuke ^[1]; Bhattacharya, Suman ^[2]

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1. Department of Physics, Yale University, New Haven, CT 06520 (United States)
2. T-2, Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

We use an analytic model to investigate the theoretical uncertainty on the thermal Sunyaev-Zel'dovich (SZ) power spectrum due to astrophysical uncertainties in the thermal structure of the intracluster medium. Our model accounts for star formation and energy feedback (from supernovae and active galactic nuclei) as well as radially dependent non-thermal pressure support due to random gas motions, the latter calibrated by recent hydrodynamical simulations. We compare the model against X-ray observations of low-redshift clusters, finding excellent agreement with observed pressure profiles. Varying the levels of feedback and non-thermal pressure support can significantly change both the amplitude and shape of the thermal SZ power spectrum. Increasing the feedback suppresses power at small angular scales, shifting the peak of the power spectrum to lower l. On the other hand, increasing the non-thermal pressure support has the opposite effect, significantly reducing power at large angular scales. In general, including non-thermal pressure at the level measured in simulations has a large effect on the power spectrum, reducing the amplitude by 50% at angular scales of a few arcminutes compared to a model without a non-thermal component. Our results demonstrate that measurements of the shape of the power spectrum can reveal useful information on important physical processes in groups and clusters, especially at high redshift where there exists little observational data. Comparing with the recent South Pole Telescope measurements of the small-scale cosmic microwave background power spectrum, we find our model reduces the tension between the values of {sigma}{sub 8} measured from the SZ power spectrum and from cluster abundances.

• OSTI ID: 21476710
• Journal Information: Astrophysical Journal, Vol. 725, Issue 2; Other Information: DOI: 10.1088/0004-637X/725/2/1452; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ABUNDANCE
ASTROPHYSICS
BACKGROUND RADIATION
GALAXY CLUSTERS
GALAXY NUCLEI
RANDOMNESS
RELICT RADIATION
SIMULATION
SPECTRA
SUPERNOVAE
TELESCOPES
UNIVERSE
X RADIATION
BINARY STARS
ELECTROMAGNETIC RADIATION
ERUPTIVE VARIABLE STARS
IONIZING RADIATIONS
MICROWAVE RADIATION
PHYSICS
RADIATIONS
STARS
VARIABLE STARS