标题： 弱引力透镜对室女座星系团的研究 显示英文标题

标题： A weak lensing study of the Coma cluster

摘要： 由于观测限制，基于弱引力透镜的附近星系团暗物质测定仍然极为罕见，尽管它们对于独立于其他方法确定星系团特性非常重要。 我们基于在加拿大-法国-夏威夷望远镜（CFHT）获得的深场图像，对室女座星系团（红移0.024）进行了弱引力透镜研究。 在基于u (1x1 deg2)波段以及B、V、R和I波段（42'x52'）的深场图像获得我们视野中星系的光度红移后，使我们能够消除前景星系，然后我们在u图像中进行形状测量并应用弱引力透镜计算。 我们得到了室女座星系团的质量分布图，以及径向剪切轮廓，以及不同半径处的质量和集中参数。 我们得到M_200c = 5.1+4.3-2.1 x10^14 Msun 和 c_200c=5.0+3.2-2.5，与之前的测量结果一致。 利用深场大视场图像，现在可以使用弱引力透镜技术分析附近的星系团，从而开辟了一个新的广泛研究领域。 显示英文摘要

摘要： Due to observational constraints, dark matter determinations in nearby clusters based on weak lensing are still extremely rare, in spite of their importance for the determination of cluster properties independent of other methods. We present a weak lensing study of the Coma cluster (redshift 0.024) based on deep images obtained at the CFHT. After obtaining photometric redshifts for the galaxies in our field based on deep images in the u (1x1 deg2), and in the B, V, R and I bands (42'x52'), allowing us to eliminate foreground galaxies, we apply weak lensing calculations on shape measurements performed in the u image. We derive a map of the mass distribution in Coma, as well as the radial shear profile, and the mass and concentration parameter at various radii. We obtain M_200c = 5.1+4.3-2.1 x10^14 Msun and c_200c=5.0+3.2-2.5, in good agreement with previous measurements. With deep wide field images it is now possible to analyze nearby clusters with weak lensing techniques, thus opening a broad new field of investigation.