The M/L versus velocity dispersion
The dynamical mass-to-light (M/L) ratio and the strength of the higher order Balmer lines Hδ and Hγ versus the velocity dispersion of the galaxy. The M/L versus velocity dispersion relation is a representation of the Fundamental Plane. The solid blue line shows the best fit to the low-redshift samples (Coma, Perseus and A194), while the dot-dashed lines show models for formation redshifts dependent on the velocity dispersions, color-coded for each of the clusters. The M/L ratios are modeled reasonably well by these models. However, the strength of the Balmer lines is significantly weaker than expected from the models, indicating that the M/L ratios and the Balmer line measurements cannot be reconciled with a simple passive evolution model with a formation redshift depending on the galaxy velocity dispersion.
Credit:NOIRLab/Gemini Observatory/AURA
About the Image
Id: | geminiann13002a |
Type: | Chart |
Release date: | Feb. 1, 2013, 3:28 p.m. |
Related announcements: | geminiann13002 |
Size: | 500 x 764 px |
About the Object
Category: | Gemini Observatory Illustrations |