Optical-to-virial velocity ratios of local disc galaxies from combined kinematics and galaxy–galaxy lensing
Optical-to-virial velocity ratios of local disc galaxies from combined kinematics and galaxy–galaxy lensing
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DOI：
10.1111/j.1365-2966.2012.21472.x
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发表时间：
2011-10
影响因子：
4.8
通讯作者：
R. Reyes;R. Mandelbaum;J. Gunn;R. Nakajima;U. Seljak;C. Hirata
中科院分区：
文献类型：
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作者：
R. Reyes;R. Mandelbaum;J. Gunn;R. Nakajima;U. Seljak;C. Hirata
本文测量了Sloan数字巡天（SDSS）中平均红移为0.07、恒星质量为10^9 < M* < 10^（11）M_xm的盘星系的光维里速度比V_（opt）/V_（200 c）。V_（opt）/V_（200 c）是在盘状星系光学半径（100 kpc）处测得的圆速度与暗物质晕维里半径（150 kpc）处测得的圆速度之比，是盘状星系形成的一个强有力的观测约束。它动态地将星系与它们的暗物质晕联系起来，并将盘星系的总质量分布约束在一个数量级的长度尺度上。对于这个测量，我们结合联合收割机Vopt从塔利-费舍尔关系（TFR）从雷耶斯等人。与V200 c来自晕质量测量星系-星系透镜。在这种组合的预期中，我们使用类似的选择星系样本的TFR和透镜分析。对于透镜加权平均质量分别为0.6、2.7和6.5 × 10^（10）M_∞的三个M* 仓，我们得到晕-星质量比M_（200 c）/M_* = 41，23和26，1σ统计不确定度约为0.1 dex，V_（opt）/V_（200 c）= 1.27 ± 0.08，1.39 ± 0.06和1.27 ± 0.08（1σ）。我们的结果表明，暗物质和重子的贡献的质量内的光学半径是可比的，如果暗物质晕配置文件没有被重子显着修改。在这项工作中获得的结果将作为盘星系形成模型的输入和限制，这将在未来的工作中进行探讨。最后，我们注意到，本文提出了一个新的和改进的星系形状目录弱透镜，涵盖了完整的SDSS数据发布7足迹。
In this paper, we measure the optical-to-virial velocity ratios V_(opt)/V_(200c) of disc galaxies in the Sloan Digital Sky Survey (SDSS) at a mean redshift of 〈z〉 = 0.07 and with stellar masses 10^9 < M* < 10^(11) M_⊙. V_(opt)/V_(200c), the ratio of the circular velocity measured at the optical radius of the disc (∼10 kpc) to that at the virial radius of the dark matter halo (∼150 kpc), is a powerful observational constraint on disc galaxy formation. It links galaxies to their dark matter haloes dynamically and constrains the total mass profile of disc galaxies over an order of magnitude in length scale. For this measurement, we combine Vopt derived from the Tully–Fisher relation (TFR) from Reyes et al. with V200c derived from halo masses measured with galaxy–galaxy lensing. In anticipation of this combination, we use similarly selected galaxy samples for both the TFR and lensing analysis. For three M* bins with lensing-weighted mean stellar masses of 0.6, 2.7 and 6.5 × 10^(10) M_⊙, we find halo-to-stellar mass ratios M_(200c)/M_* = 41, 23 and 26, with 1σ statistical uncertainties of around 0.1 dex, and V_(opt)/V_(200c) = 1.27 ± 0.08, 1.39 ± 0.06 and 1.27 ± 0.08 (1σ), respectively. Our results suggest that the dark matter and baryonic contributions to the mass within the optical radius are comparable, if the dark matter halo profile has not been significantly modified by baryons. The results obtained in this work will serve as inputs to and constraints on disc galaxy formation models, which will be explored in future work. Finally, we note that this paper presents a new and improved galaxy shape catalogue for weak lensing that covers the full SDSS Data Release 7 footprint.