Chemodynamics of barred galaxies in cosmological simulations: On the Milky Way's quiescent merger history and in-situ bulge

Abstract

We explore the chemodynamical properties of a sample of barred galaxies in the Auriga magneto-hydrodynamical cosmological zoom-in simulations, which form boxy/peanut (b/p) bulges, and compare these to the Milky Way (MW). We show that the Auriga galaxies which best reproduce the chemodynamical properties of stellar populations in the MW bulge have quiescent merger histories since redshift $z\sim 3.5$: their last major merger occurs at $t_{\mathrm{lookback}}>12\mathrm{Gyrs}$, while subsequent mergers have a stellar mass ratio of $\le$1:20, suggesting an upper limit of a few percent for the mass ratio of the recently proposed Gaia Sausage/Enceladus merger. These Auriga MW-analogues have a negligible fraction of ex-situ stars in the b/p region ($<1\%$), with flattened, thick disc-like metal-poor stellar populations. The average fraction of ex-situ stars in the central regions of all Auriga galaxies with b/p's is 3% -- significantly lower than in those which do not host a b/p or a bar. While the central regions of these barred galaxies contain the oldest populations, they also have stars younger than 5Gyrs (>30%) and exhibit X-shaped age and abundance distributions. Examining the discs in our sample, we find that in some cases a star-forming ring forms around the bar, which alters the metallicity of the inner regions of the galaxy. Further out in the disc, bar-induced resonances lead to metal-rich ridges in the $V_{\varphi }-r$ plane -- the longest of which is due to the Outer Lindblad Resonance. Our results suggest the Milky Way has an uncommonly quiet merger history, which leads to an essentially in-situ bulge, and highlight the significant effects the bar can have on the surrounding disc.

Accepted for publication in MNRAS; 19 pages, 17 figures + 6 pages of appendices; Updated figures 11 and 12 (show the relation between chemodynamics and formation history)

References in corpus (38)

• The Auriga Project: the properties and formation mechanisms of disc galaxies across cosmic time
• Structural Properties of Pseudo-Bulges, Classical Bulges and Elliptical Galaxies: an SDSS Perspective
• Rapid formation of exponential disks and bulges at high redshift from the dynamical evolution of clump cluster and chain galaxies
• A Near-Infrared Study of 2MASS Bars in Local Galaxies: An Anchor for High Redshift Studies
• The population of barred galaxies in the local universe I. Detection and characterisation of bars
• The Biggest Splash
• A First Constraint on the Thick Disk Scale Length: Differential Radial Abundances in K Giants at Galactocentric Radii 4, 8, and 12 kpc
• Image Decomposition of Barred Galaxies and AGN Hosts
• Stellar Proper Motions in the Galactic Bulge from deep HST ACS/WFC Photometry
• The GIRAFFE Inner Bulge Survey (GIBS) III. Metallicity distributions and kinematics of 26 Galactic bulge fields
• The Gaia-ESO Survey: metallicity and kinematic trends in the Milky Way bulge
• The total stellar halo mass of the Milky Way
• On the origin of rR_1 ring structures in barred galaxies
• Origin of chemically distinct discs in the Auriga cosmological simulations
• Sausage & Mash: The dual origin of the Galactic thick disc and halo from the gas-rich Gaia-Enceladus-Sausage merger
• Gas accretion and galactic fountain flows in the Auriga cosmological simulations: angular momentum and metal re-distribution
• The Fornax 3D project: unveiling the thick disk origin in FCC 170: signs of accretion?
• Peanuts, brezels and bananas: food for thought on the orbital structure of the Galactic bulge
• The Pristine Inner Galaxy Survey (PIGS) I: Tracing the kinematics of metal-poor stars in the Galactic bulge
• On the ridges, undulations & streams in Gaia DR2: Linking the topography of phase-space to the orbital structure of an N-body bar
• Resonances in Barred Galaxies
• Properties of HI discs in the Auriga cosmological simulations
• A Gaia-Enceladus Analog in the EAGLE Simulation: Insights into the Early Evolution of the Milky Way
• Age Dating the Galactic Bar with the Nuclear Stellar Disc
• Metallicity-dependendent kinematics and morphology of the Milky Way bulge
• The inner two degrees of the Milky Way. Evidence of a chemical difference between the Galactic Center and the surrounding inner bulge stellar populations
• The distribution of stellar population age in galactic bars
• Redistribution of Stars and Gas in the Star Formation Deserts of Barred Galaxies
• Clocking the assembly of double-barred galaxies with the MUSE TIMER project
• The Effects of Boxy/Peanut Bulges on Galaxy Models
• Structural and photometric properties of barred galaxies from the Auriga cosmological simulations
• SDSS-IV MaNGA: Bar pattern speed estimates with the Tremaine-Weinberg method and their error sources
• What the Milky Way bulge reveals about the initial metallicity gradients in the disc
• The central spheroids of Milky Way mass-sized galaxies
• Bars & boxy/peanut bulges in thin & thick discs: I. Morphology and line-of-sight velocities of a fiducial model
• Survival of molecular gas in a stellar feedback-driven outflow witnessed with the MUSE TIMER project and ALMA
• The chemistry of stars in the bar of the Milky Way
• Peanut-shaped metallicity distributions in bulges of edge-on galaxies: the case of NGC 4710

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