Cosmological simulations of the formation of the stellar haloes around disc galaxies

By A. Font, Ian G. McCarthy, Robert A. Crain, Tom Theuns, Joop Schaye, R. Wiersma, Claudio Dalla Vecchia. 2011

231 citations recorded by the source corpus.

We use the Galaxies-Intergalactic Medium Interaction Calculation (GIMIC) suite of cosmological hydrodynamical simulations to study the formation of stellar spheroids of Milky Way mass disc galaxies. The simulations contain accurate treatments of metal-dependent radiative cooling, star formation, supernova feedback and chemodynamics, and the large volumes that have been simulated yield an unprecedentedly large sample of ≈400 simulated ∼L∗ disc galaxies. The simulated galaxies are surrounded by low-mass, low surface brightness stellar haloes that extend out to ∼100 kpc and beyond. The diffuse stellar distributions bear a remarkable resemblance to those observed around the Milky Way, M31 and other nearby galaxies, in terms of mass density, surface brightness and metallicity profiles. We show that in situ star formation typically dominates the stellar spheroids by mass at radii of r 30 kpc, whereas accretion of stars dominates at larger radii and this change in origin induces a change in the slope of the surface brightness and metallicity profiles, which is also present in the observational data. The system-to-system scatter in the in situ mass fractions of the spheroid, however, is large and spans over a factor of 4. Consequently, there is a large degree of scatter in the shape and normalization of the spheroid density profile within r 30 kpc (e.g. when fitted by a spherical power-law profile, the indices range from −2.6 to −3.4). We show that the in situ mass fraction of the spheroid is linked to the formation epoch of the system. Dynamically, older systems have, on average, larger contributions from in situ star formation, although there is significant system-to-system scatter in this relationship. Thus, in situ star formation likely represents the solution to the long-standing failure of pure accretion-based models to reproduce the observed properties of the inner spheroid.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/7b1f48f1cc08cffd80f833ced1923f8d9ff3c170

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

Citations in the corpus

The Galaxy in Context: Structural, Kinematic, and Integrated Properties (2016, background): “…disk could have been ejected into the inner halo, and further in situ halo stars could have formed from gas stripped from infalling satellites (Font et al. 2011, McCarthy et al. 2012, Tissera et al. 2013, Cooper et al. 2015, Pillepich et al. 2015), but the quantitative importance of these…”
Evidence from the H3 Survey That the Stellar Halo Is Entirely Comprised of Substructure (2020, background): “…accreted, stripped from infalling galaxies, or ejected in outflows —are debated across simulations and may help constrain subgrid physics such as star formation and feedback prescriptions (e.g., Font et al. 2011, 2020; Cooper et al. 2015; Pillepich et al. 2018; Fattahi et al. 2020; Yu et al. 2020).”
KINEMATICS OF THE STELLAR HALO AND THE MASS DISTRIBUTION OF THE MILKY WAY USING BLUE HORIZONTAL BRANCH STARS (2012, background): “Additionally, duality in the formation history of the halo hasl o been seen in the recent smooth particle hydrodynamics and N-body simulations by Zolotov et al. (2009); McCarthy et al. (2012); Font et al. (2011).”
WIDE-FIELD PRECISION KINEMATICS OF THE M87 GLOBULAR CLUSTER SYSTEM (2011, background): “A metallicity transition with radius may be seen as a sign of a two-phase assembly scenario, with the inner component having formed in situ (Zolotov et al. 2009; Coccato et al. 2010; Font et al. 2011).”
The Aquila comparison project: the effects of feedback and numerical methods on simulations of galaxy formation (2011, methodology): “A full description of the model can be found in Crain et al. (2009) and Schaye et al. (2010) and further applications of this model can be found in Crain et al. (2010), Cui et al. (2011), Deason et al. (2011), Font et al. (2011) and McCarthy et al. (2011).”
Extragalactic science, cosmology, and Galactic archaeology with the Subaru Prime Focus Spectrograph (2012, background): “All of these processes are predicted to be controlled by hierarchical clustering of CDM via self-gravity on galactic and sub-galactic scales (e.g., Bullock & Johnston 2005; Cooper et al. 2010; Font et al. 2011).”
THE RELATIONSHIPS AMONG COMPACT STELLAR SYSTEMS: A FRESH VIEW OF ULTRACOMPACT DWARFS (2011, background): “These interpretations can be connected to a broad framework for different modes of galaxy assembly (e.g., Carollo et al. 2007; Zolotov et al. 2009; Forbes & Bridges 2010; Forbes et al. 2011; Oser et al. 2010; Arnold et al. 2011; Font et al. 2011).”
A fundamental problem in our understanding of low-mass galaxy evolution (2012, background): “…simulations have been shown to reproduce several properties of L⋆ galaxies, such as their X-ray to optical luminosity scaling relations (Crain et al. 2010), their stellar halo structure and dynamics (Font et al. 2011; McCarthy et al. 2012a) and their Tully-Fisher relation (McCarthy et al. 2012b).”
Near-Field Cosmology with Extremely Metal-Poor Stars (2015, background): “…terms on an inner component that may have formed in situ during the evolution of the Milky Way, together with a more diffuse outer one that originated from past accretion and tidal disruption of dwarf galaxies (Zolotov et al. 2009, 2010, Font et al. 2011, McCarthy et al. 2012, Tissera et al. 2014).”
METALLICITY EVOLUTION OF DAMPED Lyα SYSTEMS OUT TO z ∼ 5 (2012, background): “It is likely that the answer lies somewhere in-between, with both processes playing a role (Majewski 1993; Chiba & Beers 2000; Helmi 2008; Font et al. 2011).”
A-type stars in the Canada–France Imaging Survey – II. Tracing the height of the disc at large distances with Blue Stragglers (2018, background): “…of the Galaxy that formed in situ and the fraction that originally came from the Galactic disc (e.g. Eggen, Lynden-Bell & Sandage 1962; Searle & Zinn 1978; Carollo et al. 2007, 2010; Font et al. 2011; Rodriguez-Gomez et al. 2016; Deason et al. 2017; Belokurov et al. 2018; Pillepich et al. 2018).”
Why does the environmental influence on group and cluster galaxies extend beyond the virial radius (2012, background): “The simulations also reproduce the observed scalings of hot gas X-ray luminosity with K-band luminosity, star-formation rate and rotation velocity (Crain et al. 2010), as well as the properties of stellar haloes around Milky Way-mass disc galaxies (Font et al. 2011; McCarthy et al. 2012a).”
The stellar mass assembly of galaxies in the Illustris simulation: growth by mergers and the spatial distribution of accreted stars (2015, background): “…half-mass radius, and is larger than the in situ half-mass radius for galaxies of all masses, as expected from the accretion origin of the former (e.g. Searle & Zinn 1978; Abadi, Navarro & Steinmetz 2006; Zolotov et al. 2009; Font et al. 2011; Pillepich et al. 2014; Pillepich, Madau & Mayer 2015).”
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 Font et al. (2011) analysis emphasizes the structural characteristics of their simulations; they find remarkable similarities to the observed characteristics of the Milky Way reported by C07, C10, and de Jong et al. (2010), including the detection of “breaks” in the stellar spatial-density…”
The origin of discs and spheroids in simulated galaxies (2011, background): “The first analyses of z = 0 GIMIC galaxies (Crain et al. 2010; Font et al. 2011; McCarthy et al. 2012) show that they are fairly realistic, so we feel confident that we can use them to gain insight into the origin of galaxy morphology.”
Star formation sustained by gas accretion (2014, background): “2.5 Accretion and disk growth Accretion tends to favor the outer parts of galaxies with both stars from minor mergers (Font et al. 2011; Lackner et al. 2012) and gas from cold streams (Roškar et al. 2010; Moran et al. 2012).”
Galactic accretion and the outer structure of galaxies in the CDM model (2013, methodology): “…massive quiescent galaxies (Meza et al. 2003; Naab et al. 2009; Oser et al. 2010) and Milky Way-like galaxies (Abadi, Navarro & Steinmetz 2006; Cooper et al. 2010; Font et al. 2011; Sales et al. 2012) we emphasize the difference between in situ star formation and galactic accretion in our analysis.”