“文献：星系团”的版本间差异

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::Yx a simple product of TX and Mg,500 and is related to the total thermal energy of the ICM.
::Yx a simple product of TX and Mg,500 and is related to the total thermal energy of the ICM.



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*The Lx-Tvir relation in galaxy clusters: Effects of radiative cooling and AGN heating arXiv:1106.5185:HIFLUGCS samplethe non-cool-core clusters (NCCs) with long cooling times (> 7:7 Gyr) to display the shallowest (LX / T2:42�0:21 vir ). This has the simple implication that on the high-mass scale (Tvir > 2:5 keV) the steepening of the LX - Tvir relation is mainly due to the cooling of the intracluster medium gas.We propose that ICM

cooling and AGN heating are both important in shaping the LX-Tvir relation but on di�erent length-scales. While our study indicates that ICM cooling dominates on cluster scales (Tvir > 2:5 keV), we speculate that AGN heating dominates the scaling relation in poor clusters and groups (Tvir < 2:5 keV).:AGN对Lx的贡献考虑cool－core 的影响之后不明显。
*The Lx-Tvir relation in galaxy clusters: Effects of radiative cooling and AGN heating arXiv:1106.5185

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HIFLUGCS samplethe non-cool-core clusters (NCCs) with long cooling times (> 7:7 Gyr) to display the shallowest (LX / T2:42�0:21 vir ). This has the simple implication that on the high-mass scale (Tvir > 2:5 keV) the steepening of the LX - Tvir relation is mainly due to the cooling of the intracluster medium gas.We propose that ICM cooling and AGN heating are both important in shaping the LX-Tvir relation but on di�erent length-scales. While our study indicates that ICM cooling dominates on cluster scales (Tvir > 2:5 keV), we speculate that AGN heating dominates the scaling relation in poor clusters and groups (Tvir < 2:5 keV).

:AGN对Lx的贡献考虑cool－core 的影响之后不明显。

*XCS： XMM Cluster Survey Catalog
http://xcs-home.org/datareleases http://arxiv.org/abs/1106.3056
#10 clusters at high redshift (z > 1.0,including a new spectroscopically-confirmed cluster at z = 1.01);
#67 clusters with high TX (> 5 keV);
#131 clusters/groups with low TX (< 2 keV);
#27 clusters with measured TX values in the SDSS ‘Stripe 82’ co-add region;
#78 clusters with measured TX values in the Dark Energy Survey region;
#40 clusters detected with sufficient counts to permit mass measurements (under the assumption of hydrostatic equilibrium);
#105 clusters that can be used for applications such as the derivation of cosmological parameters and the measurement of cluster scaling relations.


==光学==
==光学==

2013年12月19日 (四) 07:31的版本

X-ray

  • X-ray under-luminous galaxy cluster arXiv:1109.4031 Andreon & Moretti

SDSS maxBCG选的星系团。计算swift观测的33个星系团的X射线流量 重点讨论了，background 的误差，大于Possion弥散，因此对低表面亮度的星系团的光度误差影响很大。 结论：没有显著的X-ray under-luminous galaxy cluster 原因：

  1. 误差被低估
  2. 采用的Lx-N200 的scaling relation可能是bised（比如X射线选）
  • Kravtsov 2006 A New Robust Low-Scatter X-Ray Mass Indicator for Clusters of Galaxies
Lx -Yx relation Yx 最好的星系团质量的indicator
Yx a simple product of TX and Mg,500 and is related to the total thermal energy of the ICM.


  • The Lx-Tvir relation in galaxy clusters: Effects of radiative cooling and AGN heating arXiv:1106.5185

HIFLUGCS samplethe non-cool-core clusters (NCCs) with long cooling times (> 7:7 Gyr) to display the shallowest (LX / T2:42�0:21 vir ). This has the simple implication that on the high-mass scale (Tvir > 2:5 keV) the steepening of the LX - Tvir relation is mainly due to the cooling of the intracluster medium gas.We propose that ICM cooling and AGN heating are both important in shaping the LX-Tvir relation but on di�erent length-scales. While our study indicates that ICM cooling dominates on cluster scales (Tvir > 2:5 keV), we speculate that AGN heating dominates the scaling relation in poor clusters and groups (Tvir < 2:5 keV).

AGN对Lx的贡献考虑cool－core 的影响之后不明显。
  • XCS： XMM Cluster Survey Catalog

http://xcs-home.org/datareleases http://arxiv.org/abs/1106.3056

  1. 10 clusters at high redshift (z > 1.0,including a new spectroscopically-confirmed cluster at z = 1.01);
  2. 67 clusters with high TX (> 5 keV);
  3. 131 clusters/groups with low TX (< 2 keV);
  4. 27 clusters with measured TX values in the SDSS ‘Stripe 82’ co-add region;
  5. 78 clusters with measured TX values in the Dark Energy Survey region;
  6. 40 clusters detected with sufficient counts to permit mass measurements (under the assumption of hydrostatic equilibrium);
  7. 105 clusters that can be used for applications such as the derivation of cosmological parameters and the measurement of cluster scaling relations.

光学

  • Wen Z.L. 2009 Galaxy clusters identified from the SDSS DR6
建立了一个基于SDSS DR6的星系测光红移的星系团样本。选择的星系为了volume complete，Mr<-21和Abell团，maxBCG作了比较。也和NORAS，REFLEX的X射线星系团作了比较。

得到的Lx-Lr的斜率是2.8（Section5.1)和Rykoff（2008）的基于RASS的星系团的结果（1.72）差别较大。

细节：文中定义了一个gross galaxy number，GGN，星系到r_{GGN}范围内的总数目（去除背景）。

r_{GGN}是星系数目降到背景程度处的半径，可能大于1Mpc。

GGN和Richness 相关,Richnes定义为1Mpc范围内星系的数目。
  • Tavasoli S. A statistical study of the luminosity gap in galaxy groups
讨论了星系群中的luminosity gap。gap较大的定义为fossil group，对比研究fossil group中的BCG的性质。
通过观测，随机，模拟各种不同情况下的Gap，得出1,4之间的Gap比1,2更好的结论。
  • Barkhouse W. The Luminosity Function of Low-Redshift Abell Galaxy Clusters
研究了Abell星系团中星系的光度函数。结果M*基本是个普适常数，暗段的alpha在星系外围比中心更更陡。
蓝星系比红星系的alpha更陡（-1.7），但和中心距离的相关性较弱。
M*和星系团的BM type弱相关。
细节: Bgc: cluster center-galaxy correlation amplitude 可以近似为星系团的richness （Yee & Ellingson 2003）
BM type （Bautz Morgan， 1970）：星系团的形态 I - II -III，从早到晚型，从完全动力学年老到年轻，BCG从显著到不显著。
BM type早的星系团中M*稍暗，这与星系动力学充分演化后，BCG吃掉一些亮星系的场景一致。
  • WINGS星系团中的red-sequence arXiv:1109.4011
WINGS (WIde-field Nearby Galaxy-cluster Survey)
78个X射线选的，近距离的星系团样本。
多波段数据（6500光谱，U,B,V,J,K星等, Halpha窄带）
从颜色，星等，光谱信息，统计上提取每个cluster的RS (red-sequence)
RS的性质（如亮／暗比），蓝星系的比例等发现和星系团的整体质量，BCG等都无相关性。
相关性最强的是local density。（surprise）

Scaling relation

  • Shaw, L.D 2010 Non-Gaussian Scatter in Cluster Scaling Relations
讨论了星系团中各种Scaling relation的非高斯性对结果的影响

理论模型

  • 流体静力学平衡arXiv 1109.2834
假设1，暗物质遵从 NFW分布
假设2，气体遵从一个号称universal的Generalized的NFW分布（ Arnnaud et al. 2010)
假设3，质量由暗物质主导由静力学平衡方程 dP/dr=-rou GM(r)/r (压力梯度=引力)

然后得到一系列解析解.

取自“http://202.127.29.3/~shen/wiki/index.php?title=文献：星系团&oldid=959”