The assembly of the most rotationally supported disc galaxies in the TNG100 simulations

Abstract

Disc dominated galaxies can be difficult to accommodate in a hierarchical formation scenario like $\Lambda$CDM, where mergers are an important growth mechanism. However, observational evidence indicates that these galaxies are common. We seek to characterise the conditions that lead to the formation of disc dominated galaxies within $\Lambda$CDM. We use dynamical decomposition in all galaxies with stellar mass $M_{\ast }=[10^{10}-10^{11}]{\mathrm{M}}_{\odot }$ within the simulation Illustris TNG100. We select a sample of 43 mostly-disc galaxies having less than $\sim 10\%$ of their mass into a bulge component. For comparison, we also study two additional stellar-mass matched samples: 43 intermediate galaxies having $\sim 30\%$ of their mass in the bulge and 43 with purely spheroidal-like morphology. We find that the selection based on stellar dynamics is able to reproduce the expected stellar population trends of different morphologies, with higher star-formation rates and younger stars in disc-dominated galaxies. Halo spin seems to play no role in the morphology of the galaxies. At fixed $M_{\ast }$, our mostly-disc and intermediate samples form in dark matter haloes that are $2$-$10$ times less massive than the spheroidal sample, highlighting a higher efficiency in disc galaxies to retain and condensate their baryons. On average, mergers are less prevalent in the build up of discs than in spheroidal galaxies, but there is a large scatter, including the existence of mostly-disc galaxies with $15\%$-$30\%$ of their stars from accreted origin. Discs start forming early on, settling their low vertical velocity dispersion as early as $9$-$10$ Gyr ago, although the dominance of the disc over the spheroid gets established more recently ($3$-$4$ Gyr ago). The most rotationally supported discs form in haloes with the lowest mass in the sample and best aligned distribution of angular momentum in the gas.

arXiv comment11 pages, 12 figures. Submitted to A&A. Abstract was abriged to meet arXiv requirements

References in corpus (60)

• Planck 2015 results. XIII. Cosmological parameters
• The EAGLE project: Simulating the evolution and assembly of galaxies and their environments
• Populating a cluster of galaxies - I. Results at z=0
• First results from the IllustrisTNG simulations: matter and galaxy clustering
• First results from the IllustrisTNG simulations: the stellar mass content of groups and clusters of galaxies
• First results from the IllustrisTNG simulations: the galaxy color bimodality
• Properties of galaxies reproduced by a hydrodynamic simulation
• First results from the IllustrisTNG simulations: A tale of two elements -- chemical evolution of magnesium and europium
• Substructures in hydrodynamical cluster simulations
• A universal angular momentum profile for galactic halos
• Galaxy Clustering in the Completed SDSS Redshift Survey: The Dependence on Color and Luminosity
• The merger rate of galaxies in the Illustris Simulation: a comparison with observations and semi-empirical models
• Galaxy evolution in groups and clusters: satellite star formation histories and quenching timescales in a hierarchical Universe
• Simulations of Galaxy Formation in a Lambda CDM Universe II: The Fine Structure of Simulated Galactic Disks
• How Do Disks Survive Mergers?
• The Horizon-AGN simulation: morphological diversity of galaxies promoted by AGN feedback
• The stellar mass assembly of galaxies in the Illustris simulation: growth by mergers and the spatial distribution of accreted stars
• The Aquila comparison Project: The Effects of Feedback and Numerical Methods on Simulations of Galaxy Formation
• Quantifying the Fragility of Galactic Disks in Minor Mergers
• EMERGE - An empirical model for the formation of galaxies since $z\sim 10$
• Early Evolution of Disk Galaxies : Formation of Bulges in Clumpy Young Galactic Disks
• Bulgeless Giant Galaxies Challenge our Picture of Galaxy Formation by Hierarchical Clustering
• The Formation and Survival of Discs in a Lambda-CDM Universe
• The Origin of Disks and Spheroids in Simulated Galaxies
• Angular momentum and galaxy formation revisited
• Merger Histories of Galaxy Halos and Implications for Disk Survival
• The Nearly Universal Merger Rate of Dark Matter Haloes in Lambda-CDM Cosmology
• Galactic Angular Momentum in the Illustris Simulation: Feedback and the Hubble Sequence
• From dawn till disk: Milky Way's turbulent youth revealed by the APOGEE+Gaia data
• The role of mergers and halo spin in shaping galaxy morphology
• Strong bimodality in the host halo mass of central galaxies from galaxy-galaxy lensing
• Feedback and the Structure of Simulated Galaxies at redshift z=2
• Discovery of Face-On Counterparts of Chain Galaxies in the Tadpole ACS Field
• Stellar Feedback & Bulge Formation in Clumpy Disks
• Why stellar feedback promotes disc formation in simulated galaxies
• Satellite abundances around bright isolated galaxies
• The formation and evolution of low-surface-brightness galaxies
• The origin of the diverse morphologies and kinematics of Milky Way-mass galaxies in the FIRE-2 simulations
• The impact of stellar feedback on the structure, size and morphology of galaxies in Milky Way size dark matter haloes
• Merger Rates of Dark-Matter Haloes
• A diversity of progenitors and histories for isolated spiral galaxies
• The link between the assembly of the inner dark matter halo and the angular momentum evolution of galaxies in the EAGLE simulation
• Peak star formation efficiency and no missing baryons in massive spirals
• A Catalog of Edge-on Disk Galaxies: From Galaxies with a Bulge to Superthin Galaxies
• Hot-mode accretion and the physics of thin-disk galaxy formation
• The statistical properties of LCDM halo formation
• Dynamical evidence for a morphology-dependent relation between the stellar and halo masses of galaxies
• Barred Galaxies in the IllustrisTNG Simulation
• NIHAO XXI: The emergence of Low Surface Brightness galaxies
• Born this way: thin disc, thick disc, and isotropic spheroid formation in FIRE-2 Milky-Way-mass galaxy simulations
• Origin and evolution of ultra-diffuse galaxies in different environments
• Galactic angular momentum in the IllustrisTNG simulation -- I. Connection to morphology, halo spin, and black hole mass
• Formation of the Large Nearby Galaxies
• The Three-Phase Evolution of the Milky Way
• The vertical structure of gaseous galaxy discs in cold dark matter halos
• The High Fraction of Thin Disk Galaxies Continues to Challenge ΛCDM Cosmology
• The formation of low surface brightness galaxies in the IllustrisTNG simulation
• Massive Low Surface Brightness Galaxies in the EAGLE Simulation
• The evolutionary pathways of disk galaxies with different sizes
• Untangling Stellar Components of Galaxies: Evaluation of Dynamical Decomposition Methods in Simulated Galaxies with GalaxyChop

Cited by in corpus (1)

• Bulgeless Evolution And the Rise of Discs (BEARD) II. The role of mergers in shaping the Milky Way analogues in TNG50