Using angular momentum maps to detect kinematically distinct galactic components

Irodotou, Dimitrios and Thomas, Peter A (2021) Using angular momentum maps to detect kinematically distinct galactic components. Monthly Notices of the Royal Astronomical Society, 501 (2). pp. 2182-2197. ISSN 0035-8711

[img] PDF - Published Version
Download (13MB)


In this work, we introduce a physically motivated method of performing disc/spheroid decomposition of simulated galaxies, which we apply to the EAGLE sample. We make use of the HEALPIX package to create Mollweide projections of the angular momentum map of each galaxy’s stellar particles. A number of features arise on the angular momentum space which allows us to decompose galaxies and classify them into different morphological types. We assign stellar particles with angular separation of less/greater than 30° from the densest grid cell on the angular momentum sphere to the disc/spheroid components, respectively. We analyse the spatial distribution for a subsample of galaxies and show that the surface density profiles of the disc and spheroid closely follow an exponential and a Sérsic profile, respectively. In addition discs rotate faster, have smaller velocity dispersions, are younger and are more metal rich than spheroids. Thus, our morphological classification reproduces the observed properties of such systems. Finally, we demonstrate that our method is able to identify a significant population of galaxies with counter-rotating discs and provide a more realistic classification of such systems compared to previous methods.

Item Type: Article
Schools and Departments: School of Mathematical and Physical Sciences > Physics and Astronomy
SWORD Depositor: Mx Elements Account
Depositing User: Mx Elements Account
Date Deposited: 06 Jan 2021 08:19
Last Modified: 06 Jan 2021 08:30

View download statistics for this item

📧 Request an update