Chandra observations of the Planck Early Sunyaev-Zeldovich sample a reexamination of masses and mass proxies. (2021)
Keywords :
Galaxy clusters ; Intracluster medium ; Sunyaev-Zeldovich effect
Abstract:Using Chandra observations, we derive the YX proxy and associated total mass measurement, M_500_^Yx^ for 147 clusters with z<0.35 from the Planck early Sunyaev-Zeldovich catalog, and for 80 clusters with z<0.22 from an X-ray flux-limited sample. We reextract the Planck Y_SZ_ measurements and obtain the corresponding mass proxy, M_500_^SZ^, from the full Planck mission maps, minimizing Malmquist bias due to observational scatter. The masses reextracted using the more precise X-ray position and characteristic size agree with the published PSZ2 values, but yield a significant reduction in the scatter (by a factor of two) in the M_500_^SZ^-M_500_^Yx^ relation. The slope is 0.93+/-0.03, and the median ratio,
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For our investigation, we make use of the following cluster samples:
1. An SZ-selected sample of clusters derived from the first catalog of
189 objects detected in the first 10 months of the Planck survey, and
released in early 2011 (Planck Collaboration VIII 2011, VIII/88).
A Chandra X-Ray Visionary Program (PI: Jones) and High Resolution
Camera (HRC) Guaranteed Time Observations (PI: Murray) were combined
to form the Chandra-Planck Legacy Program for Massive Clusters of
Galaxies. For each of the 163 ESZ Planck clusters at z<0.35, we
obtained Chandra exposures sufficient to collect at least 10000 source
counts. Figure 1 displays a mosaic of the 147 clusters from the ESZ
sample that are used in this work. See Section 2.
2. An X-ray-selected sample of high-flux clusters.
Voevodkin & Vikhlinin (2004ApJ...601..610V) compiled a sample of the
52 X-ray-brightest clusters in the local universe by selecting the
highest-flux objects detected in the ROSAT All-sky Survey at
|b|>20{deg} and z>0.025 --using the HIFLUGCS catalog as reference.
The sample used here is an extension of Voevodkin & Vikhlinin's (2004)
approach, where the flux limit in the 0.5-2.0keV band was lowered to
f_X_>7.5x10^-12^erg/s/cm2. We obtained a sample of 80 clusters which
all have Chandra observations. See Section 2.
Throughout this paper, we assume a standard {Lambda}CDM cosmology with
H_0_=70km/s/Mpc, {Omega}_M_=0.3, and {Omega}_{Lambda}_=0.7. The
variables M_500_ and R_500_ are the total mass within R_500_ and the
radius corresponding to a total density contrast {Delta}=500 as
compared to {rho}c(z), the critical density of the universe at the
cluster redshift. The SZ flux is characterized by Y_500_^SZ^ (in
square arcminutes), or simply Y_SZ_. The quantity D_A_^2^Y_SZ_ is then
the spherically integrated Compton parameter within R_500_ (in square
megaparsecs), where DA is the angular diameter distance of the
cluster. All uncertainties are quoted at the 1{sigma} (68% confidence)
level.
- B/chandra : The Chandra Archive Log (CXC, 1999-2014)
- VIII/88 : Planck Early Release Compact Source Catalogue (Planck, 2011)
- VIII/91 : Planck Catalog of Compact Sources Release 1 (Planck, 2013)
- J/ApJ/511/65 : Einstein images of galaxy clusters (Jones & Forman, 1999)
- J/A+A/536/A8 : Planck early results. VIII. ESZ sample. (Planck+, 2011)
- J/A+A/575/A30 : HIFLUGCS XMM/Chandra cross-calibration (Schellenberger+, 2015)
- J/A+A/594/A27 : Planck Sunyaev-Zeldovich sources (PSZ2) (Planck+, 2016)
- J/ApJ/843/76 : Cool-core clusters with Chandra obs. (Andrade-Santos+, 2017)
- J/MNRAS/469/3738 : Complete sample of galaxy clusters (Schellenberger+, 2017)
- J/MNRAS/468/3322 : CoMaLit. V. Mass forecasting with proxies (Sereno+, 2017)
