Chemical signatures of formation processes in the stellar populations of simulated galaxies

By Patricia B. Tissera, Simon D. M. White, Cecilia Scannapieco Iafe, Conicet-UBA, Argentina., Mpa, Garching, Heidelberg · Germany, Aip, Postdam. 2011

132 citations recorded by the source corpus.

We study the chemical properties of the stellar populations in eight simulations of the formation of Milky Way mass galaxies in a Λ cold dark matter universe. Our simulations include metal-dependent cooling and an explicitly multiphase treatment of the effects on the gas of cooling, enrichment and supernova feedback. We search for correlations between formation history and chemical abundance patterns. Differing contributions to spheroids and discs from in situ star formation and from accreted populations are reflected in differing chemical properties. Discs have younger stellar populations, with most stars forming in situ and with low α-enhancement from gas which never participated in a galactic outflow. Up to 15 per cent of disc stars can come from accreted satellites. These tend to be α-enhanced, older and to have larger velocity dispersions than the in situ population. Inner spheroids have old, metal-rich and α-enhanced stars which formed primarily in situ, more than 40 per cent from material recycled through earlier galactic winds. Few accreted stars are found in the inner spheroid unless a major merger occurred recently. Such stars are older, more metal-poor and more α-enhanced than the in situ population. Stellar haloes tend to have low metallicity and high α-enhancement. The outer haloes are made primarily of accreted stars. Their mean metallicity and α-enhancement reflect the masses of the disrupted satellites where they formed: more massive satellites typically have higher [Fe/H] and lower [α/Fe]. Surviving satellites have distinctive chemical patterns which reflect their extended, bursty star formation histories. These produce lower α-enhancement at given metallicity than in the main galaxy, in agreement with observed trends in the Milky Way.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/3359bd3f7a478c5d67bace03358abad0568ec447

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 Instrumentation

Citations in the corpus

Chemodynamical evolution of the Milky Way disk - I. The solar vicinity (2012, background): “…(e.g., Kobayashi et al., 2007) or the metallicity trends between the different Galactic components (e.g., Tissera et al., 2012), it is still a challenge for these simulations to match the properties of the MW (e.g., the typical metallicities of the different components – Tissera et al. 2012).”
The RAVE survey : the Galactic escape speed and the mass of the Milky Way (2013, background): “Our choice is, in addition, close to half of the distance of the Milky Way and its nearest massive neighbor, the Andromeda galaxy.”
Galactic star formation and accretion histories from matching galaxies to dark matter haloes (2012, background): “In lower-mass disk-like galaxies the accreted stars contribute to the build-up of the outer stellar halo and can also directly contribute on the order of 10 percent to the stel- lar mass of the disk (e.g. Abadi et al. 2006; Font et al. 2011; Tissera et al. 2012).”
THE CASE FOR THE DUAL HALO OF THE MILKY WAY (2011, background): “The Tissera et al. (2011) study emphasizes the contrasting chemical properties of the components they associate with an inner halo and outer halo in their suite of simulations, separated on the basis of the binding energy of the stellar particles.”
Towards a more realistic population of bright spiral galaxies in cosmological simulations (2013, methodology): “jz/(rVcirc(r)) with Vcirc = √ GM(< r)/r. Comparing Figure 3 of CS09 to Figure 2 of Tissera et al. (2012), who used the same definition as we did and analyzed the models of CS09, illustrates how the definition of circularity affects the shape of the circularity distribution. hardly any disk and…”
The cosmic baryon cycle and galaxy mass assembly in the FIRE simulations (2016, background): “…is commonly analyzed in simulations in terms of the contributions from in situ star formation and ex situ stellar growth (Oser et al. 2010; Lackner et al. 2012; Tissera et al. 2012; Naab et al. 2014; Hirschmann et al. 2015; Pillepich et al. 2015; Qu et al. 2016; Rodriguez-Gomez et al. 2016).”