Strong-lensing Measurement of the Mass-density Profile out to 3 Effective Radii for $z \sim 0.5$ Early-type Galaxies [GA]

http://arxiv.org/abs/1805.06624


We obtain the total mass-density profiles out to three effective radii for a sample of 63 intermediate-redshift early-type galaxies (ETGs) through a joint analysis of strong gravitational lensing and stellar dynamics. The sample is compiled from three galaxy-scale strong-lens surveys, including the Baryon Oscillation Spectroscopic Survey (BOSS) Emission-Line Lens Survey (BELLS), BELLS for GALaxy-Ly EmitteR sYstems (BELLS GALLERY) Survey, and Strong Lensing Legacy Survey (SL2S). The lens redshifts of the sample have a mean value of $0.52$, but the source redshifts span a wide range from $0.8$ to $3.5$, which leads to a wide range of Einstein radii up to three effective radii. We find that: (1) the total mass distribution is very close to isothermal one with the average logarithmic density slope $\langle\gamma\rangle=2.000_{-0.032}^{+0.033}$ ($68\%$CL) and intrinsic scatter $\delta=0.180_{-0.028}^{+0.032}$, similar with previous work. (2) we normalize the Einstein radius by the effective radius to study whether the slope $\gamma$ evolutes along radius for a fixed galaxy. We find the density profile would be steeper with increasing radius. Therefore, We conclude that the total mass-density slope have a slight increasing trend along radius for a fixed galaxy, which is consistent with previous numerical simulation depending on galactic wind and AGN feedback

Read this paper on arXiv…

R. Li, Y. Shu and J. Wang
Fri, 18 May 18
24/51

Comments: 7 pages, 4 figures, 1 table