New Galaxy Groups from the RASS Thomas Reiprich http://dark-energy.net
(Snowcluster 2010) Outer Temperature Profiles with Suzaku r 200 Abell 2204; Reiprich et al. (2009)
(Snowcluster 2015) erosita/srg Launch Date: Dec 2016 Primary Science Driver: Dark Energy with Clusters 1.5 million km from Earth erosita Update: Talk Florian P., tomorrow From Baikonur to L2 orbit Zenit-2SB rocket Fregat booster Spektr-RG mission Navigator platform ART-XC / erosita Merloni et al. (2012) 3
(Snowcluster 2018) Overview 1. Observations of large X-ray selected galaxy cluster samples a) Cosmological constraints with individual cluster masses from the best-observed sample. b) Previously missed RASS groups. c) Unexpected anisotropies in the cluster L-T relation. d) The ultimate X-ray sample before erosita: eehiflugcs. 2. Athena early galaxy groups (-> Talk Etienne P., tomorrow) 4
Latest Cosmology Results from X-ray-Selected Clusters Data analysis and L X M relation: Schellenberger & Reiprich (2017a). Cosmology: Schellenberger & Reiprich (2017b). 5
HIFLUGCS 64 Brightest Clusters Sample selection described in Reiprich & Boehringer (2002) and Hudson+10. 6
IJ ~100 ks (clean) per cluster 7
Results Robust results on Ω m and σ 8 from mass function (MF) and f gas for z > 0.05 clusters. Potential for good leverage on neutrino masses, theoretical mass function, etc. once groups are under control. 8
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Schellenberger & Reiprich (2017b) 10
Missed Groups in the RASS? Search for Them on Wavelet-Filtered Images, Detection Optimized for Very Extended Sources W. Xu, M. Ramos-Ceja, F. Pacaud, T. Reiprich, T. Erben (subm.) 11
Missed Groups in the RASS? ~1,300 candidates found, ~700 of them are not known as X-ray or SZ clusters. SDSS, ~20 arcmin W. Xu, M. Ramos-Ceja, F. Pacaud, T. Reiprich, T. Erben (subm.) Observations 12
No known X-ray/SZ cluster (but Abell) SDSS ATLAS (~20 arcmin)
RASS, ~1 deg, no known X-ray/SZ cluster (but Abell) 14
ATLAS (Klaes, Wright, Erben, ), ~0.5 deg 15
One Step Further New cluster candidates that do not have a previous X-ray detection in any RASS catalog (e.g., ROSAT faint source catalog). This means these clusters will not be found in any optical survey that follows up all known RASS sources, even including point sources. ~200 candidates, pilot sample of 13 easy ones just submitted. 16
SDSS RASS, 1 deg height 17
SDSS RASS, 1 deg height 18
SDSS RASS, 1 deg height 19
DSS RASS, 1 deg height 20
DSS RASS, 1 deg height 21
ATLAS RASS, 1 deg width 22
ATLAS RASS, 1 deg height 23
All groups: z < 0.08 Redshifts 24
All Groups: Emission detected to >10 ~6 Groups: f X > 3x10 12 erg/s/cm 2 All Groups: M < 10 14 M ~2 Groups: outside R 200 of major cluster 25
All Groups: Flat Surface Brightness Dist. Beta = 2/3 26
All Groups: Flat Surface Brightness Dist. 27
Extended nearby groups with flat SB distrib s were missed in RASS catalogs. Next step: check if it s a significant fraction, and if it s a new population. W. Xu, M. Ramos-Ceja, F. Pacaud, T. Reiprich, T. Erben (subm.) 28
Possible Quantitative Implications HIFLUGCS Example = 75% missed = 50% missed Incomplete parent catalogs at group scale? Schellenberger & Reiprich (2017b) 29
Shape of Local Mass Function Constrains both Ω m and σ 8. R. Hanson 30
Cosmological Principle The Universe is isotropic for us (and every other comoving observer) on large scales. Friedmann equations follow from this (plus GR). These simple equations are the basis for calculating the size and density evolution of the Universe. 31
New Method to Test for Luminosity Distance Anisotropies ACC ~Group A ACC (273): D. Horner (2001) XCS (364): Mehrtens+12 Migkas & Reiprich (2017) 32
L-T Relation ~Group A ~Group A Migkas & Reiprich (2017) 33
Analogous Constraints on H 0 Migkas & Reiprich (2017) 34
New Method to Test for Luminosity Distance Anisotropies Discovery of ~significant (~3σ) unexpected anisotropy of the L-T relation across the sky. Two independent samples show the same behavior (à 2x ~3σ). Now, increase homogeneous sample size and photon statistics with eehiflugcs and erosita. 35
eehiflugcs ~400 X-ray brightest clusters in sky. (Almost) complete high-quality follow-up with Chandra and/or XMM-Newton. Reiprich (AN, 2017) Ramos-Ceja, Pacaud, Lovisari, Schellenberger, Migkas, TR+, in prep. 36
The Future: Athena in >=2028 ESA Large Mission 37
Detection of High-z Groups with WFI@Athena [80ks] ß 40 à C. Zhang, M. Ramos-Ceja, F. Pacaud, TR, SIXTE simulator from C. Schmidt, T. Dauser, J. Wilms, 38
Detection of High-z Groups with WFI@Athena [80ks] ~4800 cts ~2400 cts ß 40 à C. Zhang, M. Ramos-Ceja, F. Pacaud, TR, SIXTE simulator from C. Schmidt, T. Dauser, J. Wilms, 39
Lissajous Dither Pattern C. Zhang+ 40
M = 5e13 Msun, z = 1 Dithered observation, R 500 of input clusters. C. Zhang+ Wavelet-filtered image and groups detected as extended sources, despite central AGN. 41
M = 5e13 Msun, z = 2.5 Dithered observation, R 500 of input clusters. C. Zhang+ Wavelet-filtered image and groups detected as extended sources, despite central AGN. 42
80 ks, M = 5e13Msun, including central AGN. Sources detected as extended. C. Zhang+ 43
Expect >= 10 groups at z >= 2 with M 500 >= 5e13Msun with gas temperature measurement directly from WFI survey to be discovered in first 4 years (assuming 15 mirror rows). 44
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Summary 1. Observations of large X-ray selected galaxy cluster samples a) Cosmological constraints with individual cluster masses from the best-observed sample. b) Previously missed RASS clusters. c) Unexpected anisotropies in the cluster L-T relation. d) The ultimate X-ray sample before erosita: eehiflugcs. 2. Athena early galaxy groups IJ 46