THE METALLICITY EVOLUTION OF INTERACTING GALAXIES

By P. Torrey, Thomas J. Cox, Lisa J. Kewley, L. Hernquist. 2011

140 citations recorded by the source corpus.

Nuclear inflows of metal-poor interstellar gas triggered by galaxy interactions can account for the systematically lower central oxygen abundances observed in local interacting galaxies. Here, we investigate the metallicity evolution of a large set of simulations of colliding galaxies. Our models include cooling, star formation, feedback, and a new stochastic method for tracking the mass recycled back to the interstellar medium from stellar winds and supernovae. We study the influence of merger-induced inflows, enrichment, gas consumption, and galactic winds in determining the nuclear metallicity. The central metallicity is primarily a competition between the inflow of low-metallicity gas and enrichment from star formation. An average depression in the nuclear metallicity of ∼0.07 is found for gas-poor disk–disk interactions. Gas-rich disk–disk interactions, on the other hand, typically have an enhancement in the central metallicity that is positively correlated with the gas content. The simulations fare reasonably well when compared to the observed mass–metallicity and separation–metallicity relationships, but further study is warranted.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/c3859ca3a4d6ce2e9d230d2d709c6bab51822175

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In Astronomy and Astrophysics

1. P. Hopkins
2. L. Hernquist
3. R. Dav'e
4. Volker Springel
5. T. Naab
6. R. Somerville
7. E. Quataert
8. Thomas J. Cox

In Instrumentation

1. P. Hopkins
2. L. Hernquist
3. R. Dav'e
4. Thomas J. Cox
5. Volker Springel
6. A. Dekel
7. T. Naab
8. R. Somerville

Citations in the corpus

• The SINS/zC-SINF Survey of z ∼ 2 Galaxy Kinematics: SINFONI Adaptive Optics–assisted Data and Kiloparsec-scale Emission-line Properties (2018, background): “…predictions from theoretical models and simulations (e.g., Rahimi et al. 2011; Kobayashi & Nakasato 2011; Few et al. 2012; Pilkington et al. 2012; Torrey et al. 2012; Gibson et al. 2013; Mott et al. 2013), these findings have been interpreted as resulting from externally-driven…”
• The structure of the interstellar medium of star‐forming galaxies (2011, methodology): “This is implemented following the methodology of Torrey et al. (2012), with a few minor modifications.”
• Metallicity evolution, metallicity gradients, and gas fractions at z ~ 3.4 (2013, background): “…at z∼3.4 from the FMR may be associated with an increased rate of mergers, which destabilize low metallicity gas in galaxy outskirts and drive it towards the central, active regions as suggested by some models (e.g. Rupke et al. 2010; Perez et al. 2011; Pilkington et al. 2012; Torrey et al. 2012).”
• Star formation sustained by gas accretion (2014, background): “Even for large returned fractions R = 0.5 (e.g., Edmunds 2005; Leitner & Kravtsov 2011; Torrey et al. 2012) and moderate outflows w = 0.2 (e.g., Zahid et al. 2012, ; see also Sect.”
• First results from the IllustrisTNG simulations: a tale of two elements - chemical evolution of magnesium and europium (2017, background): “…of SNIa (e.g., Wiersma et al. 2009; Walcher et al. 2016), nucleosynthesis yields (e.g. Tinsley 1979; Prantzos et al. 1994; Thomas 1999), and environmental parameters which determine how enriched and pristine gas is mixed before forming stars with a specific yield pattern (e.g., Torrey et al. 2012).”
• THE MASS–METALLICITY RELATION WITH THE DIRECT METHOD ON STACKED SPECTRA OF SDSS GALAXIES (2012, background): “Major mergers drive in considerable amounts of low metallicity gas from large radii, which dilutes the metallicity of the galaxy and triggers vigorous star formation (e.g., Kewley et al. 2006, 2010; Torrey et al. 2012).”
• Metallicity gradients in local field star-forming galaxies: insights on inflows, outflows, and the coevolution of gas, stars and metals (2015, background): “Both bservations and simulations confirm that mergers of disk galaxies present shallower metallicity gradients than isolated disk galaxies due to effective gas mixing (e.g.,Kewley et al. 2010; Rupke et al. 2008, 2010a,b; Torrey et al. 2012; Rich et al. 2012).”
• THEORETICAL EVOLUTION OF OPTICAL STRONG LINES ACROSS COSMIC TIME (2013, background): “Theory indicates that metallicity gradients systematically flatten after first pericenter and flatten again during final coalescence (Rupke et al. 2010a; Torrey et al. 2012).”
• Star formation in galaxy mergers with realistic models of stellar feedback and the interstellar medium (2012, background): “…that can separately follow stellar winds and SNe of Types I and II on the age, metallicity and abundance (α/Fe) gradients in the galaxies; these can place strong constraints on the merger history and role of dissipation in galaxy formation (see e.g. Torrey et al. 2012a, and references therein).”
• Gaseous Galaxy Halos (2012, background): “Perturbations by companions will result in mixing (e.g., Torrey et al., 2012) and can warp the gas disks (Binney, 1992).”
• NEW STRONG-LINE ABUNDANCE DIAGNOSTICS FOR H ii REGIONS: EFFECTS OF κ-DISTRIBUTED ELECTRON ENERGIES AND NEW ATOMIC DATA (2013, background): “…maintained (Bothun et al. 1984; Wyse & Silk 1985; Skillman et al. 1989; Vila-Costas & Edmunds 1992; Zaritsky et al. 1994; van Zee et al. 1998), and discover how abundance gradients can be removed in galaxy interactions (Kewley et al. 2010; Rupke et al. 2010; Torrey et al. 2012; Rich et al. 2012).”
• The star formation main sequence and stellar mass assembly of galaxies in the Illustris simulation (2014, methodology): “However, in higher-resolution idealised merger simulations that employed the same ISM model, SFR elevations of an order of magnitude or more have been found (e.g. Cox et al. 2008; Hayward et al. 2011, 2014; Torrey et al. 2012).”
• Galaxy pairs in the Sloan Digital Sky Survey – VIII. The observational properties of post-merger galaxies (2013, background): “…completely transform the galaxy’s morphology (e.g. Barnes & Hernquist 1996; Di Matteo, Springel & Hernquist 2005; Springel, Di Matteo & Hernquist 2005; Di Matteo et al. 2007, 2008; Cox et al. 2008; Montuori et al. 2010; Rupke, Kewley & Barnes 2010; Perez et al. 2011; Torrey et al. 2012).”
• Galaxy pairs in the Sloan Digital Sky Survey – V. Tracing changes in star formation rate and metallicity out to separations of 80 kpc (2012, methodology): “A suite of simulations based on the work in Torrey et al. (2012) is developed to allow us to analyse the trends with rp for characteristic markers of the merger stages.”
• Galaxy pairs in the Sloan Digital Sky Survey – VI. The orbital extent of enhanced star formation in interacting galaxies (2013, methodology): “…2005) which – in addition to including gravity and hydrodynamics – accounts for radiative cooling of gas (Katz, Weinberg, & Hernquist 1996), a density−driven SFR prescription with associated feedback (Springel & Hernquist 2003), and gas recycling from aging stellar populations (Torrey et al. 2012).”
• A characteristic oxygen abundance gradient in galaxy disks unveiled with CALIFA (2013, background): “This flattening is compounded as the spiral arms are stretched by tidal effects (Torrey et al. 2012).”