X-ray scaling relations from a complete sample of the richest maxBCG clusters

Journal Article · Thu Jan 10 00:00:00 EST 2019 · Monthly Notices of the Royal Astronomical Society

DOI:https://doi.org/10.1093/mnras/stz088· OSTI ID:1612350

Ge, Chong ^[1]; Sun, Ming ^[2]; Rozo, Eduardo ^[3]; Sehgal, Neelima ^[4]; Vikhlinin, Alexey ^[5]; Forman, William ^[5]; Jones, Christine ^[5]; Nagai, Daisuke ^[6]

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1. Univ. of Alabama, Huntsville, AL (United States); DOE/OSTI
2. Univ. of Alabama, Huntsville, AL (United States)
3. Univ. of Arizona, Tucson, AZ (United States)
4. Stony Brook Univ., NY (United States)
5. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)
6. Yale Univ., New Haven, CT (United States)

Here, we use a complete sample of 38 richest maxBCG clusters to study the ICM–galaxy scaling relations and the halo mass selection properties of the maxBCG algorithm, based on X-ray and optical observations. The clusters are selected from the two largest bins of optical richness in the Planck stacking work with the maxBCG richness N₂₀₀ ≥ 78. We analyse their Chandra and XMM–Newton data to derive the X-ray properties of the ICM. We then use the distribution of P(X|N), X = T_X, L_X, Y_X, to study the mass selection P(M|N) of maxBCG. Compared with previous works based on the whole richness sample, a significant fraction of blended systems with boosted richness is skewed into this richest sample. Parts of the blended haloes are picked apart by the redMaPPer, an updated red-sequence cluster finding algorithm with lower mass scatter. Moreover, all the optical blended haloes are resolved as individual X-ray haloes, following the established L_X-T_X and L_X-Y_X relations. We further discuss that the discrepancy between ICM–galaxy scaling relations, especially for future blind stacking, can come from several factors, including miscentring, projection, contamination of low-mass systems, mass bias, and covariance bias. We also evaluate the fractions of relaxed and cool core clusters in our sample. Both are smaller than those from SZ or X-ray selected samples. Moreover, disturbed clusters show a higher level of mass bias than relaxed clusters.

• Research Organization: Univ. of Arizona, Tucson, AZ (United States)
• Sponsoring Organization: National Aeronautic and Space Administration (NASA); National Science Foundation (NSF); USDOE Office of Science (SC)
• Grant/Contract Number: SC0015975
• OSTI ID: 1612350
• Journal Information: Monthly Notices of the Royal Astronomical Society, Journal Name: Monthly Notices of the Royal Astronomical Society Journal Issue: 2 Vol. 484; ISSN 0035-8711
• Publisher: Royal Astronomical Society
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
Astronomy & Astrophysics
X-rays: galaxies: clusters
galaxies: clusters: general
galaxies: clusters: intracluster medium