The effect of the environment on the stellar mass-size relationship for present-day galaxies

Cebrián, M.; Trujillo, I.
Bibliographical reference

Monthly Notices of the Royal Astronomical Society, Volume 444, Issue 1, p.682-699

Advertised on:
10
2014
Number of authors
2
IAC number of authors
2
Citations
56
Refereed citations
55
Description
In order to study how the environment can influence the relationship between the stellar mass and effective radius for nearby galaxies (z < 0.12), we use a mass-complete sample extracted from the NYU-Value Added Galaxy Catalogue. This sample contains almost 232 000 objects with masses of up to 3 × 1011 M⊙. For every galaxy in our sample, we explore the surrounding density within 2 Mpc using two distinct estimators of the environment. We find that galaxies are slightly larger in the field than in high-density regions. This effect is more pronounced for late-type morphologies (˜7.5 per cent larger) and especially at low masses (M* < 2 × 1010 M⊙), although it is also measurable in early-type galaxies (˜3.5 per cent larger). The environment also leaves a subtle imprint in the scatter of the stellar mass-size relation. This scatter is larger in low-density regions than in high-density regions for both morphologies, on average ˜3.5 per cent larger for early-type and ˜0.8 per cent for late-type galaxies. Late-type galaxies with low masses (M* < 2 × 1010 M⊙) show the largest differences in the scatter among environments. The scatter is ˜20 per cent larger in the field than in clusters for these low-mass objects. Our analysis suggests that galaxies in clusters form earlier than those in the field. In addition, cluster galaxies seem to originate from a more homogeneous family of progenitors.
Related projects
Group members
Traces of Galaxy Formation: Stellar populations, Dynamics and Morphology
We are a large, diverse, and very active research group aiming to provide a comprehensive picture for the formation of galaxies in the Universe. Rooted in detailed stellar population analysis, we are constantly exploring and developing new tools and ideas to understand how galaxies came to be what we now observe.
Ignacio
Martín Navarro