Planck intermediate results: XXXVII. Evidence of unbound gas from the kinetic Sunyaev-Zeldovich effect

Research output: Contribution to journalArticle

Researchers

  • P. A. R. Ade
  • N. Aghanim
  • M. Arnaud
  • M. Ashdown
  • E. Aubourg
  • J. Aumont
  • C. Baccigalupi
  • A. J. Banday
  • R. B. Barreiro
  • N. Bartolo
  • E. Battaner
  • K. Benabed
  • A. Benoit-Levy
  • M. Bersanelli
  • P. Bielewicz
  • J. J. Bock
  • A. Bonaldi
  • L. Bonavera
  • J. R. Bond
  • J. Borrill
  • F. R. Bouchet
  • C. Burigana
  • E. Calabrese
  • J. -F. Cardoso
  • A. Catalano
  • A. Chamballu
  • H. C. Chiang
  • P. R. Christensen
  • D. L. Clements
  • L. P. L. Colombo
  • C. Combet
  • B. P. Crill
  • A. Curto
  • F. Cuttaia
  • L. Danese
  • R. D. Davies
  • R. J. Davis
  • P. de Bernardis
  • G. de Zotti
  • J. Delabrouille
  • C. Dickinson
  • J. M. Diego
  • K. Dolag
  • S. Donzelli
  • O. Doré
  • M. Douspis
  • A. Ducout
  • X. Dupac
  • J. Leon-Tavares
  • Matti Savelainen

  • Planck Collaboration

Research units

  • Ludwig Maximilian University of Munich
  • International School for Advanced Studies
  • Istituto Nazionale di Fisica Nucleare
  • University of Granada
  • Nicolaus Copernicus Astronomical Center
  • University of California at Berkeley
  • Universite Paris Sorbonne - Paris IV
  • University of Oxford
  • Telecom Paris Tech
  • University of KwaZulu-Natal
  • University of Rome La Sapienza
  • INAF, Osservatorio Astronomico di Padova
  • Instituto Nacional de Astrofisica Optica y Electronica
  • University of Turku
  • Cardiff University
  • Université Paris-Sud 11
  • Université Paris Diderot
  • Kavli Institute for Cosmology Cambridge
  • University of Cambridge
  • Université de Toulouse
  • CNRS
  • Universidad de Cantabria
  • Università Degli Studi di Padova
  • Université Pierre and Marie Curie
  • University College London
  • Università degli Studi di Milano
  • INAF/IASF Milano
  • California Institute of Technology
  • University of Manchester
  • University of Toronto
  • Lawrence Berkeley National Laboratory
  • INAF/IASF Bologna
  • University of Ferrara
  • INFN, Sezione di Bologna
  • Université Grenoble Alpes
  • CEA Saclay, CEA, DSM Irfu SPP
  • Princeton University
  • Niels Bohr Institute
  • Imperial College London
  • University of Southern California
  • Max-Planck-Institut für Astrophysik
  • European Space Agcy, European Space Agency, ESAC, Planck Sci Off
  • University of Helsinki
  • Helsinki Institute of Physics

Abstract

By looking at the kinetic Sunyaev-Zeldovich effect (kSZ) in Planck nominal mission data, we present a significant detection of baryons participating in large-scale bulk flows around central galaxies (CGs) at redshift z approximate to 0.1. We estimate the pairwise momentum of the kSZ temperature fluctuations at the positions of the Central Galaxy Catalogue (CGC) samples extracted from Sloan Digital Sky Survey (SDSS-DR7) data. For the foreground-cleaned SEVEM, SMICA, NILC, and COMMANDER maps, we find 1.8-2.5 sigma detections of the kSZ signal, which are consistent with the kSZ evidence found in individual Planck raw frequency maps, although lower than found in the WMAP-9yr W-band (3.3 sigma). We further reconstruct the peculiar velocity field from the CG density field, and compute for the first time the cross-correlation function between kSZ temperature fluctuations and estimates of CG radial peculiar velocities. This correlation function yields a 3.0-3.7 sigma detection of the peculiar motion of extended gas on Mpc scales in flows correlated up to distances of 80-100 h(-1) Mpc. Both the pairwise momentum estimates and the kSZ temperature-velocity field correlation find evidence for kSZ signatures out to apertures of 8 arcmin and beyond, corresponding to a physical radius of >1 Mpc, more than twice the mean virial radius of halos. This is consistent with the predictions from hydrodynamical simulations that most of the baryons are outside the virialized halos. We fit a simple model, in which the temperature-velocity cross-correlation is proportional to the signal seen in a semi-analytic model built upon N-body simulations, and interpret the proportionality constant as an effective optical depth to Thomson scattering. We find tau(T) = (1.4 +/- 0.5) x 10(-4); the simplest interpretation of this measurement is that much of the gas is in a diffuse phase, which contributes little signal to X-ray or thermal Sunyaev-Zeldovich observations.

Details

Original languageEnglish
Article number140
Number of pages14
JournalAstronomy and Astrophysics
Volume586
Publication statusPublished - Feb 2016
MoE publication typeA1 Journal article-refereed

    Research areas

  • cosmic background radiation, cosmology: observations, large-scale structure of Universe, galaxies: clusters: intracluster medium, PARTICLE HYDRODYNAMICS SIMULATIONS, BULK FLOW, DENSITY FIELDS, COSMOLOGICAL IMPLICATIONS, WIENER RECONSTRUCTION, PECULIAR VELOCITIES, REDSHIFT SURVEYS, GALAXY SAMPLES, IRAS-GALAXIES, DARK ENERGY

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