Bibcode
Janz, J.; Vijayaraghavan, R.; Peletier, R.; Falcón-Barroso, J.; van de Ven, G.; Vazdekis, A.; Kuntschner, H.; Lisker, T.; Sybilska, A.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 470, Issue 1, p.815-838
Advertised on:
9
2017
Citations
26
Refereed citations
26
Description
We present the first in a series of papers in The role of Environment in
shaping Low-mass Early-type Nearby galaxies (hELENa) project. In this
paper, we combine our sample of 20 low-mass early types (dEs) with 258
massive early types (ETGs) from the ATLAS3D survey - all
observed with the SAURON integral field unit - to investigate early-type
galaxies' stellar population scaling relations and the dependence of the
population properties on local environment, extended to the low-σ
regime of dEs. The ages in our sample show more scatter at lower σ
values, indicative of less massive galaxies being affected by the
environment to a higher degree. The shape of the age-σ relations
for cluster versus non-cluster galaxies suggests that cluster
environment speeds up the placing of galaxies on the red sequence. While
the scaling relations are tighter for cluster than for the field/group
objects, we find no evidence for a difference in average population
characteristics of the two samples. We investigate the properties of our
sample in the Virgo cluster as a function of number density (rather than
simple clustrocentric distance) and find that dE ages correlate with the
local density such that galaxies in regions of lower density are
younger, likely because they are later arrivals to the cluster or have
experienced less pre-processing in groups, and consequently used up
their gas reservoir more recently. Overall, dE properties correlate more
strongly with density than those of massive ETGs, which was expected as
less massive galaxies are more susceptible to external influences.
Related projects
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