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Recent measurements of the Sunyaev-Zeldovich (SZ) angular power spectrum from the South Pole Telescope (SPT) and the Atacama Cosmology Telescope (ACT) demonstrate the importance of understanding baryon physics when using the SZ power spectrum to constrain cosmology. This is challenging since roughly half of the SZ power at l=3000 is from low-mass systems with 10^13 h^-1 M_sun < M_500 < 1.5x10^14 h^-1 M_sun, which are more difficult to study than systems of higher mass. We present a study of the thermal pressure content for a sample of local galaxy groups from Sun et al. (2009). The group Y_{sph, 500} - M_500 relation agrees with the one for clusters derived by Arnaud et al. (2010). The group median pressure profile also agrees with the universal pressure profile for clusters derived by Arnaud et al. (2010). With this in mind, we briefly discuss several ways to alleviate the tension between the measured low SZ power and the predictions from SZ templates.
We analyze the radial pressure profiles, the ICM clumping factor and the Sunyaev-Zeldovich (SZ) scaling relations of a sample of simulated galaxy clusters and groups identified in a set of hydrodynamical simulations based on an updated version of the
We investigate the history of galactic feedback and chemical enrichment within a sample of 15 X-ray bright groups of galaxies, on the basis of the inferred Fe and Si distributions in the hot gas and the associated metal masses produced by core-collap
Much of the baryons in galaxy groups are thought to have been driven out to large distances ($gtrsim$$R_{500}$) by feedback, but there are few constraining observations of this extended gas. This work presents the resolved Sunyaev--Zeldovich (SZ) pro
We present IRAM 30m sensitive upper limits on CO emission in the ram pressure stripped dwarf Virgo galaxy IC3418 and in a few positions covering HII regions in its prominent 17 kpc UV/Ha gas-stripped tail. In the central few arcseconds of the galaxy,
Some observations such as those presented in Walker et al. show that the observed entropy profiles of the intra-cluster medium (ICM) deviate from the power-law prediction of adiabatic simulations. This implies that non-gravitational processes, which