The Masses and Shapes of Dark Matter Halos from Galaxy-Galaxy Lensing in the CFHT Legacy Survey
The Masses and Shapes of Dark Matter Halos from Galaxy-Galaxy Lensing in the CFHT Legacy Survey
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DOI：
10.1086/521541
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发表时间：
2007-07
期刊：
影响因子：
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通讯作者：
L. Parker;H. Hoekstra;M. Hudson;L. van Waerbeke;Y. Mellier
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文献类型：
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作者：
L. Parker;H. Hoekstra;M. Hudson;L. van Waerbeke;Y. Mellier
我们使用加拿大-法国-夏威夷望远镜遗产巡天（CFHTLS）的早期数据提出了第一个星系-星系弱透镜结果。这些结果基于大约 22 deg2 的 i′ 数据。根据这些数据，我们估计红移为 0.3 时 L* 星系的平均速度色散为 137 ± 11 km s-1，维里质量 M200 为 (1.1 ± 0.2) × 1012 h-1 M☉，静止坐标系质光比为 173 ± 34 h M☉/L。我们还详细调查了系统误差的各种可能来源。此外，我们将镜头样本分成两个子样本，除以视星等，从而得到平均红移。从这些早期数据中，我们没有检测到红移从 0.45 到 0.27 时星系暗物质晕质光比的显着演变。最后，我们测试非球形星系暗物质晕。当对所有星系进行平均时，我们的结果支持在 2 σ 水平上椭圆率约为 0.3 的暗物质晕。如果选择前景透镜星系样本以支持椭圆星系，则平均晕椭圆率和该结果的显着性会增加。
We present the first galaxy-galaxy weak-lensing results using early data from the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS). These results are based on ~22 deg2 of i′ data. From these data, we estimate the average velocity dispersion for an L* galaxy at a redshift of 0.3 to be 137 ± 11 km s-1, with a virial mass, M200, of (1.1 ± 0.2) × 1012 h-1 M☉ and a rest-frame mass-to-light ratio of 173 ± 34 h M☉/L. We also investigate various possible sources of systematic error in detail. In addition, we separate our lens sample into two subsamples, divided by apparent magnitude and thus average redshift. From these early data we do not detect significant evolution in galaxy dark matter halo mass-to-light ratios at redshifts from 0.45 to 0.27. Finally, we test for nonspherical galaxy dark matter halos. Our results favor a dark matter halo with an ellipticity of ~0.3 at the 2 σ level when averaged over all galaxies. If the sample of foreground lens galaxies is selected to favor elliptical galaxies, the mean halo ellipticity and significance of this result increase.