Cluster mass profiles from weak lensing II
Cluster mass profiles from weak lensing II
复制标题
弱透镜 II 的团簇质量分布
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
L. Schneider
中科院分区：
文献类型：
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作者：
L. Schneider
在Schneider，King&Erben(2000)中，我们发展了似然技术来比较使用剪切和放大信息可以获得的星系团质量轮廓的约束。这项工作考虑了红移相当低的星系团的圆对称幂定律模型，其中源星系的红移分布可以忽略。在这里，这种处理被扩展到包括NFW轮廓，它是对来自宇宙N体模拟的星团的很好的描述，以及具有更高红移的NFW星团，其中考察了各种场景对红移分布知识的影响。由于实际上绝大多数团簇都是椭球而不是球面，所以我们研究了奇异等温椭球。我们还简要地考虑了子结构对这种似然分析的影响。总体而言，我们发现剪切信息对所考虑的NFW剖面提供了更好的约束，因此这成为下文的重点。区分NFW和幂定律轮廓的能力强烈地依赖于数据场的大小，以及可以测量椭圆度的星系的数量密度。对于较高的红移NFW剖面，当光谱红移而不是光度红移可用于透镜分析中使用的星系时，参数估计的离散度几乎没有减少(~1.5%)。
In Schneider, King & Erben (2000) we developed likelihood techniques to compare the constraints on cluster mass profiles that can be obtained using the shear and magnification information. This work considered circularly symmetric power-law models for clusters at fairly low redshifts where the redshift distribution of source galaxies could be neglected. Here this treatment is extended to encompass NFW profiles which are a good description of clusters from cosmological N-body simulations, and NFW clusters at higher redshifts where the influence of various scenarios for the knowledge of the redshift distribution are examined. Since in reality the overwhelming majority of clusters have ellipsoidal rather than spherical profiles, the singular isothermal ellipsoid (SIE) is investigated. We also briefly consider the impact of substructure on such a likelihood analysis. In general, we find that the shear information provides a better constraint on the NFW profile under consideration, so this becomes the focus of what follows. The ability to differentiate between the NFW and power-law profiles strongly depends on the size of the data field, and on the number density of galaxies for which an ellipticity can be measured. For higher redshift NFW profiles, there is very little reduction (~1.5%) in the dispersion of parameter estimates when spectroscopic redshifts, as opposed to photometric redshift estimates, are available for the galaxies used in the lensing analysis.