English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We present optical and near infrared spectroscopy obtained at Keck, VLT, andGemini for a sample of 36 secure strong gravitational lens systems and 17candidates identified as part of the SL2S survey. The deflectors are massiveearly-type galaxies in the redshift range z_d=0.2-0.8, while the lensed sourcesare at z_s=1-3.5. We combine this data with photometric and lensingmeasurements presented in the companion paper III and with lenses from theSLACS and LSD surveys to investigate the cosmic evolution of the internalstructure of massive early-type galaxies over half the age of the universe. Westudy the dependence of the slope of the total mass density profile \gamma'(\rho(r)\propto r^{-\gamma'}) on stellar mass, size, and redshift. We find thattwo parameters are sufficent to determine \gamma' with less than 6% residualscatter. At fixed redshift, \gamma' depends solely on the surface stellar massdensity \partial \gamma'/ \partial \Sigma_*=0.38\pm 0.07, i.e. galaxies withdenser stars also have steeper slopes. At fixed M_* and R_{eff}, \gamma'depends on redshift, in the sense that galaxies at a lower redshift havesteeper slopes (\partial \gamma' / \partial z = -0.31\pm 0.10). However, themean redshift evolution of \gamma' for an individual galaxy is consistent withzero d\gamma'/dz=-0.10\pm0.12. This result is obtained by combining ourmeasured dependencies of \gamma' on z,M_*,R_{eff} with the evolution of theR_{eff}-M_* taken from the literature, and is broadly consistent with currentmodels of the formation and evolution of massive early-type galaxies. Detailedquantitative comparisons of our results with theory will provide qualitativelynew information on the detailed physical processes at work.

The SL2S Galaxy-scale Lens Sample. IV. The dependence of the total mass density profile of early-type galaxies on redshift, stellar mass, and size