Loading…
Probing galaxy assembly bias with LRG weak lensing observations
Abstract In Montero-Dorta et al., we show that luminous red galaxies (LRGs) from the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS) at z ∼ 0.55 can be divided into two groups based on their star formation histories. So-called fast-growing LRGs assemble 80 per cent of their stellar mass at z...
Saved in:
Published in: | Monthly notices of the Royal Astronomical Society 2018-06, Vol.477 (1), p.L1-L5 |
---|---|
Main Authors: | , , , , , , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Request full text |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | Abstract
In Montero-Dorta et al., we show that luminous red galaxies (LRGs) from the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS) at z ∼ 0.55 can be divided into two groups based on their star formation histories. So-called fast-growing LRGs assemble 80 per cent of their stellar mass at z ∼ 5, whereas slow-growing LRGs reach the same evolutionary state at z ∼ 1.5. We further demonstrate that these two subpopulations present significantly different clustering properties on scales of ∼1−30 Mpc. Here, we measure the mean halo mass of each subsample using the galaxy–galaxy lensing technique, in the ${\sim }190\deg ^2$ overlap of the LRG catalogue and the CS82 and CFHTLenS shear catalogues. We show that fast- and slow-growing LRGs have similar lensing profiles, which implies that they live in haloes of similar mass: $\log (M_{\rm halo}^{\rm fast}/h^{-1}\mathrm{M}_{{\odot }}) = 12.85^{+0.16}_{-0.26}$ and $\log (M_{\rm halo}^{\rm slow}/h^{-1}\mathrm{M}_{{\odot }}) =12.92^{+0.16}_{-0.22}$. This result, combined with the clustering difference, suggests the existence of galaxy assembly bias, although the effect is too subtle to be definitively proven, given the errors on our current weak-lensing measurement. We show that this can soon be achieved with upcoming surveys like DES. |
---|---|
ISSN: | 1745-3925 0035-8711 1745-3933 1365-2966 |
DOI: | 10.1093/mnrasl/sly041 |