Measures of Galaxy Environment I - What is "Environment"?
By S. I. Muldrew, Darren Croton, R. Skibba, Frazer R. Pearce, H. Ann, I. Baldry, S. Brough, Yun-Young Choi, Christopher J. Conselice, N. Cowan and 12 more. 2011
176 citations recorded by the source corpus.
The influence of a galaxy’s environment on its evolution has been studied and compared extensively in the literature, although differing techniques are often used to define environment. Most methods fall into two broad groups: those that use nearest neighbours to probe the underlying density field and those that use fixed apertures. The differences between the two inhibit a clean comparison between analyses and leave open the possibility that, even with the same data, different properties are actually being measured. In this work we apply twenty published environment definitions to a common mock galaxy catalogue constrained to look like the local Universe. We find that nearest neighbour-based measures best probe the internal densities of high-mass haloes, while at low masses the inter-halo separation dominates and acts to smooth out local density variations. The resulting correlation also shows that nearest neighbour galaxy environment is largely independent of dark matter halo mass. Conversely, aperture-based methods that probe super-halo scales accurately identify high-density regions corresponding to high mass haloes. Both methods show how galaxies in dense environments tend to be redder, with the exception of the largest apertures, but these are the strongest at recovering the background dark matter environment. We also warn against using photometric redshifts to define environment in all but the densest regions. When considering environment there are two regimes: the ‘local environment’ internal to a halo best measured with nearest neighbour and ‘large-scale environment’ external to a halo best measured with apertures. This leads to the conclusion that there is no universal environment measure and the most suitable method depends on the scale being probed.
Subfields: Astronomy and Astrophysics, Electrical and Electronic Engineering, Instrumentation
View Paper: https://www.semanticscholar.org/paper/8771732c22670317eb7be116a8bd942ecba9812f
How researchers see this paper
The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.
In Astronomy and Astrophysics
In Electrical and Electronic Engineering
In Instrumentation
Citations in the corpus
- Cold gas stripping in satellite galaxies: from pairs to clusters (2016, methodology): “There are many different metrics by which one may define the environment of a galaxy, most of which have been examined extensively in the literature (see Muldrew et al. 2012, for a thorough comparison).”
- Dependence of galaxy quenching on halo mass and distance from its centre (2012, background): “For example, environment density is often measured by the distance to a galaxy’s Nth nearest neighbour (for helpful reviews of density measures see Cooper et al. 2005; Muldrew et al. 2012).”