期刊
ASTROPHYSICAL JOURNAL
卷 727, 期 2, 页码 -出版社
IOP PUBLISHING LTD
DOI: 10.1088/0004-637X/727/2/96
关键词
dark matter; galaxies: elliptical and lenticular, cD; galaxies: evolution; galaxies: fundamental parameters; galaxies: structure; gravitational lensing: strong
资金
- Australian Postgraduate Award
- Centre National des Etudes Spatiales (CNES)
- TABASGO foundation
- Kavli foundation
- NSF [NSF-0642621]
- Packard Foundation
- NASA [GO-10876, GO-11289, GO-11588, NAS 5-26555]
- National Science Foundation [PHY99-07949]
- W. M. Keck Foundation
- Science and Technology Facilities Council [ST/H00243X/1] Funding Source: researchfish
We present a joint gravitational lensing and stellar-dynamical analysis of 11 early-type galaxies (median deflector redshift z(d) = 0.5) from Strong Lenses in the Legacy Survey (SL2S). Using newly measured redshifts and stellar velocity dispersions from Keck spectroscopy with lens models from Paper I, we derive the total mass-density slope inside the Einstein radius for each of the 11 lenses. The average total density slope is found to be = 2.16(-0.09)(+0.09) (rho(tot) proportional to r(-gamma)'), with an intrinsic scatter of 0.25(-0.07)(+0.10). We also determine the dark matter fraction for each lens within half the effective radius, R-eff/2, and find the average-projected dark matter mass fraction to be 0.42(-0.08)+(0.08) with a scatter of 0.20(-0.07)(+0.09) for a Salpeter initial mass function. By combining the SL2S results with those from the Sloan Lens ACS Survey (median z(d) = 0.2) and the Lenses Structure and Dynamics Survey (median z(d) = 0.8), we investigate cosmic evolution of gamma' and find a mild trend partial derivative /partial derivative z(d) = -0.25(-0.12)(+0.10). This suggests that the total density profile of massive galaxies has become slightly steeper over cosmic time. If this result is confirmed by larger samples, it would indicate that dissipative processes played some role in the growth of massive galaxies since z similar to 1.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据