MaGICC Thick Disk I: Comparing a Simulated Disk Formed with Stellar Feedback to the Milky Way

Дата и время публикации : 2013-01-22T21:00:00Z

Авторы публикации и институты :
G. S. Stinson (MPIA)
J. Bovy (IAS)
H. -W. Rix (MPIA)
C. Brook (UA Madrid)
R. Roškar (Zurich)
J. J. Dalcanton (U of Washington)
A. V. Macciò (MPIA)
J. Wadsley (McMaster)
H. M. P. Couchman (McMaster)
T. R. Quinn (U of Washington)

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 11 page, 10 figures, submitted. Comments welcome
Первичная категория: astro-ph.GA

Все категории : astro-ph.GA, astro-ph.CO

Краткий обзор статьи: We analyse the structure and chemical enrichment of a Milky Way-like galaxy with a stellar mass of 2 10^{10} M_sun, formed in a cosmological hydrodynamical simulation. It is disk-dominated with a flat rotation curve, and has a disk scale length similar to the Milky Way’s, but a velocity dispersion that is ~50% higher. Examining stars in narrow [Fe/H] and [alpha/Fe] abundance ranges, we find remarkable qualitative agreement between this simulation and observations: a) The old stars lie in a thickened distribution with a short scale length, while the young stars form a thinner disk, with scale lengths decreasing, as [Fe/H] increases. b) Consequently, there is a distinct outward metallicity gradient. c) Mono-abundance populations exist with a continuous distribution of scale heights (from thin to thick). However, the simulated galaxy has a distinct and substantive very thick disk (h_z~1.5 kpc), not seen in the Milky Way. The broad agreement between simulations and observations allows us to test the validity of observational proxies used in the literature: we find in the simulation that mono-abundance populations are good proxies for single age populations (<1 Gyr) for most abundances.

Category: Physics