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CFHTLenS: Co-evolution of galaxies and their dark matter haloes
- Source :
- MNRAS, 447, 298 (2015)
- Publication Year :
- 2013
-
Abstract
- Galaxy-galaxy weak lensing is a direct probe of the mean matter distribution around galaxies. The depth and sky coverage of the CFHT Legacy Survey yield statistically significant galaxy halo mass measurements over a much wider range of stellar masses ($10^{8.75}$ to $10^{11.3} M_{\odot}$) and redshifts ($0.2 < z < 0.8$) than previous weak lensing studies. At redshift $z \sim 0.5$, the stellar-to-halo mass ratio (SHMR) reaches a maximum of $4.0\pm0.2$ percent as a function of halo mass at $\sim 10^{12.25} M_{\odot}$. We find, for the first time from weak lensing alone, evidence for significant evolution in the SHMR: the peak ratio falls as a function of cosmic time from $4.5 \pm 0.3$ percent at $z \sim 0.7$ to $3.4 \pm 0.2$ percent at $z \sim 0.3$, and shifts to lower stellar mass haloes. These evolutionary trends are dominated by red galaxies, and are consistent with a model in which the stellar mass above which star formation is quenched "downsizes" with cosmic time. In contrast, the SHMR of blue, star-forming galaxies is well-fit by a power law that does not evolve with time. This suggests that blue galaxies form stars at a rate that is balanced with their dark matter accretion in such a way that they evolve along the SHMR locus. The redshift dependence of the SHMR can be used to constrain the evolution of the galaxy population over cosmic time.<br />Comment: 18 pages, MNRAS, in press
- Subjects :
- Astrophysics - Cosmology and Nongalactic Astrophysics
Subjects
Details
- Database :
- arXiv
- Journal :
- MNRAS, 447, 298 (2015)
- Publication Type :
- Report
- Accession number :
- edsarx.1310.6784
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1093/mnras/stu2367