__smbhome.uscs.susx.ac.uk_bw233_Desktop_SRO_SRO - Kathy Romer_sty1284.pdf (13.78 MB)
Baryon content in a sample of 91 galaxy clusters selected by the South Pole Telescope at 0.2
journal contribution
posted on 2023-06-09, 13:58 authored by I Chiu, J J Mohr, M McDonald, S Bocquet, S Desai, M Klein, H Israel, M L N Ashby, A Stanford, B A Benson, M Brodwin, Kathy RomerKathy Romer, The DES CollaborationWe estimate total mass (M500), intracluster medium (ICM) mass (MICM), and stellar mass (M) in a Sunyaev–Zel’dovich effect (SZE) selected sample of 91 galaxy clusters with masses M500 2.5 × 1014 M and redshift 0.2 < z < 1.25 from the 2500 deg2 South Pole Telescope SPT-SZ survey. The total masses M500 are estimated from the SZE observable, the ICM masses MICM are obtained from the analysis of Chandra X-ray observations, and the stellar masses M are derived by fitting spectral energy distribution templates to Dark Energy Survey griz optical photometry and WISE or Spitzer near-infrared photometry. We study trends in the stellar mass, the ICM mass, the total baryonic mass, and the cold baryonic fraction with cluster halo mass and redshift. We find significant departures from self-similarity in the mass scaling for all quantities, while the redshift trends are all statistically consistent with zero, indicating that the baryon content of clusters at fixed mass has changed remarkably little over the past ˜9 Gyr. We compare our results to the mean baryon fraction (and the stellar mass fraction) in the field, finding that these values lie above (below) those in cluster virial regions in all but the most massive clusters at low redshift. Using a simple model of the matter assembly of clusters from infalling groups with lower masses and from infalling material from the low-density environment or field surrounding the parent haloes, we show that the measured mass trends without strong redshift trends in the stellar mass scaling relation could be explained by a mass and redshift dependent fractional contribution from field material. Similar analyses of the ICM and baryon mass scaling relations provide evidence for the so-called ‘missing baryons’ outside cluster virial regions.
Funding
University of Sussex Astronomy Consolidated Grant 2017-2020; G2050; STFC-SCIENCE AND TECHNOLOGY FACILITIES COUNCIL; ST/P000525/1
History
Publication status
- Published
File Version
- Published version
Journal
Monthly Notices Of The Royal Astronomical SocietyISSN
0035-8711Publisher
Oxford University PressExternal DOI
Issue
3Volume
478Page range
3072-3099Department affiliated with
- Physics and Astronomy Publications
Research groups affiliated with
- Astronomy Centre Publications
Full text available
- Yes
Peer reviewed?
- Yes
Legacy Posted Date
2018-06-27First Open Access (FOA) Date
2018-06-27First Compliant Deposit (FCD) Date
2018-06-26Usage metrics
Categories
No categories selectedKeywords
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC