Planckintermediate results

Abstract

We present the scaling relation between Sunyaev-Zeldovich (SZ) signal and stellar mass for almost 260,000 locally brightest galaxies (LBGs) selected from the Sloan Digital Sky Survey (SDSS). These are predominantly the central galaxies of their dark matter halos. We calibrate the stellar-to-halo mass conversion using realistic mock catalogues based on the Millennium Simulation. Applying a multi-frequency matched filter to the Planck data for each LBG, and averaging the results in bins of stellar mass, we measure the mean SZ signal down to M * ∼ 2 × 10 11 M , with a clear indication of signal at even lower stellar mass. We derive the scaling relation between SZ signal and halo mass by assigning halo properties from our mock catalogues to the real LBGs and simulating the Planck observation process. This relation shows no evidence for deviation from a power law over a halo mass range extending from rich clusters down to M 500 ∼ 2 × 10 13 M , and there is a clear indication of signal down to M 500 ∼ 4 × 10 12 M . Planck's SZ detections in such low-mass halos imply that about a quarter of all baryons have now been seen in the form of hot halo gas, and that this gas must be less concentrated than the dark matter in such halos in order to remain consistent with X-ray observations. At the high-mass end, the measured SZ signal is 20 % lower than found from observations of X-ray clusters, a difference consistent with the magnitude of Malmquist bias effects that were previously estimated for the X-ray sample.

Measurement of the thermal Sunyaev-Zel’dovich effect around cosmic voids

“…Moreover, as the tSZ signal in voids receives a relatively larger contribution from low-mass halos than that in high-density regions, our measurement is also useful for constraining the behavior of the tSZ -mass relation at low masses. Recent analyses have found inconclusive results regarding the consistency of this relation with the self-similar prediction (Y ∝ M 5/3 ) at low masses [21,22,25,51]. Void analyses, such as ours, may be useful in shedding light on this issue using forthcoming datasets.…”

Constraints on the redshift evolution of astrophysical feedback with Sunyaev-Zel’dovich effect cross-correlations

“…Planck Collaboration et al [17] correlated galaxies identified in SDSS data with Planck y maps. The galaxy catalog used by Planck Collaboration et al [17] was restricted to "isolated" galaxies in order to probe the pressure profiles of individual small mass halos (although note the issues with this approach pointed out by Le Brun et al [18], Greco et al [19], and Hill et al [12]). Several authors have also investigated related correlations between Compton-y and weak lensing [20,21].…”

Evidence of the Missing Baryons from the Kinematic Sunyaev-Zeldovich Effect in Planck Data

“…In Ref. [8] it is claimed that there is no apparent evidence for feedback effects in the tSZ luminosity of CGs, in contradiction to x-ray observations. Those analyses have been recently revisited by Ref.…”

“…[4,5] and the references therein). Nowadays, there is an ongoing debate [6][7][8][9][10][11] on whether a significant fraction of the latter component is present in the circumgalactic medium around halos, or if instead most of the gas has been expelled or never accreted due to feedback processes like galactic winds or active galactic nuclei activity. This connects the missing baryon issue with the complex problems of feedback and galaxy formation.…”