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Xiaohu Yang
Shanghai Astronomical Observatory
Beijing, 16/10/2012
十月天文论坛
Constrain cosmological parameters using observations
调和宇宙学
4% Atoms, 23% Cold Dark Matter, 73% Dark energy.
Concordance LCDM model
从调和宇宙学到精确宇宙学GalaxyDark
matter
Two types of investigations to make the link From (theoretical) halos: model the galaxy formation/distribution
The hydrodynamical simulations The semi-analytical galaxy formation models Statistical modelling: the HOD/CLF models
From (observational) galaxies: model the halo (mass) distribution Clusterings Clusters Galaxy-galaxy lensing Satellite kinamatics X-ray clusters S-Z effect
Large redshift surveys: LAMOST Using public data releases 国际合作: AS3 , BigBOSS , LSST
The correlation functions and power spectra of galaxies To constrain cosmology and galaxy formation
N-body and hydro simulations: To understanding the structure formation and galaxy
formation
Other related work 21cm, etc
伍向平等(第一缕曙光);李菂等( FAST );陈学雷等(天籁);SKA 等
Lensing毛淑德等
(I) 大尺度结构和宇宙学
LAMOST team:
(1)建设团队(2)运行团队(3)科学团队
(1)河外(2)河内
几乎所有的国内天文单位都有某种程度的参与。
HOD: understanding the clustering of galaxies
Jing et al. 1998
(1)景益鹏等( HOD );
(2)褚耀泉等(成团测量);
(3)冯珑珑等(小波)(4)詹虎等( LSST );(5)杨小虎等( CLF)(6)盘军( 3PCF )(7)李成( SDSS )(8)张骏( lensing )(9)范祖辉( lensin
g )(10)陈学雷(再电离)(11)张鹏杰(12)王慧元、王宇
Hierarchical structure formation: from C4We have a C4 ( Chinese Computational
Cosmology Consortium) collaboration in China.
Including members from: SHAO, PMO, NAOC, SCCAS
景益鹏、冯珑珑、高亮、林伟鹏、盘军、康熙、赵东海、杨小虎、张
鹏杰等
Clusters are the rarest objects in the Universe. They locate at the exponential decay region of the halo
mass function. Their clusterings show the largest bias.
They were extensively used to probe the cosmological parameters. To obtain the reliable measure of the halo masses, detailed
studies of cluster properties are necessory.
Extreme environment to probe the galaxy formation. Because of the hierarchical strucutre formation, their
member galaxies are accreted at different redshift.
Serve as the strong lens to find the highest redshift galaxies.
(II) 星系团
The halo mass function and bias
Sheth et al. (2001)
Galaxy clusters
Clusters for cosmology -- 过去
Eke et al. (1996)
精确宇宙学• 寻求和暗晕质量精确挂钩• 提高观测的完备度。• 整合多种观测结果,减小系
统误差。
Optical clusters. From spectroscopic surveys: cosmology, galaxy formation From photometric surveys: strong lensing candidates, cosmological probes
杨小虎等;文中略等 X-ray clusters
Observations: completeness? Cool core clusters? Hydrodynamical simulations to understand the gas properties
徐海光等;伍向平等;朱宗宏等;方涛涛等 Strong and weak lensing signals
Observations, model the mass distributions Giant arcs, constrain the cosmology
毛淑德等;付丽萍等;李国亮等;景益鹏等;张骏等 S-Z effect
Theoretical modellings, detectablity Stacking to get a few sigma detection
张鹏杰等;李然等;盘军等
现状: more than cosmology
每个方向都有若干课题组在从事相关研究工作;上述列表很不完全。
Giocoli et al. 2010
New App (1): Probe the galaxy formation
Question: the faint end slope of the LFs in clusters?
Rines & Geller 2008
New App (2): improve the completeness
Wang et al. 2011
(1) We extracted 1138 (RASS) X-ray clusters from liturature.
(2) About 200 are cross-matched with SDSS DR7 optical groups.
(3) The vast majority of the optical groups are not linked with any known entries.
(4) We run our own (Growth Curve Analysis) GCA code to obtain the X-ray signals from the RASS map.
(5) An additional ~10000 X-ray signals are obtained for groups with mass > 10^{13}Msun.
Optical - X-ray clusters cross-identification
New App (3): using clusters as lens to find the first galaxies
A few slides from Zheng Wei’s talk in Hefei, May 8, 2012.
Candidate Galaxy at Candidate Galaxy at zz=9.6=9.6
May 8, 2012May 8, 2012 USTCUSTC
Clusters are the rarest objects in the Universe. They locate at the exponential decay region of the halo
mass function. Their clusterings show the largest bias.
They were extensively used to probe the cosmological parameters. To obtain the reliable measure of the halo masses,
detailed studies of cluster properties are necessory. Optical clusters X-ray clusters, gas properties Strong lensing signals SZ effect
Extreme environment to probe the galaxy formation. Because of the hierarchical strucutre formation, their
member galaxies are accreted at different redshift.
Serve as the strong lens to find the first galaxies.
Summary