Bulgeless Evolution And the Rise of Discs (BEARD) I. Physical drivers of the mass-size relation for Milky Way-like galaxies

Abstract

In the standard $\Lambda$ cold dark matter ($\Lambda$CDM) cosmology, the existence of massive pure-disc galaxies remains challenging within the hierarchical framework and is key to understanding the evolutionary history of Milky Way-like systems. In this work, we investigate the physical origin of the scatter in the stellar mass-size relation of massive spiral galaxies, with a particular focus on bulgeless systems. We analyse 22 nearby bulgeless galaxies from the Bulgeless Evolution And the Rise of Discs (BEARD) survey using deep $g$- and $r$-band imaging obtained with the 2.5 m Isaac Newton Telescope Wide Field Camera. We derive surface-brightness, colour, and stellar-mass-density radial profiles to measure $R_1$, the radius where ${\Sigma }_{\ast }=1{\mathrm{M}}_{\odot }{\mathrm{pc}}^{-2}$, adopted here as a physically motivated size proxy. Point spread function (PSF) effects are corrected through star subtraction and wavelet deconvolution. BEARD bulgeless galaxies follow the tight stellar mass-$R_1$ relation defined in previous studies, with a similar scatter of $\sim 0.1$ dex. Using galaxies from the IllustrisTNG50 simulation, we find that the scatter is linked to morphology, with bulgeless, BEARD-like analogues and bulge-dominated galaxies tracing the upper and lower envelopes of the relation, respectively. This trend correlates with the specific central stellar mass density, ${\Sigma }_{1,\mathrm{kpc}}^{\mathrm{spec}}$, suggesting that differences between observations and simulations reflect the broader central-density range spanned by BEARD bulgeless galaxies. A deeper analysis of the physical driver of this morphological segregation reveals that the scatter in the mass-size relation is also related to the spatial configuration of merger events, rather than their frequency, with bulgeless systems tending to inhabit halos with a slightly higher spin. (abridged)

18 pages, 9 figures. Published in A&A

References in corpus (35)

• The Gaia mission
• Gaia Data Release 3: Summary of the content and survey properties
• 3D-HST+CANDELS: The Evolution of the Galaxy Size-Mass Distribution since $z=3$
• HyperLEDA. III. The catalogue of extragalactic distances
• The population of barred galaxies in the local universe I. Detection and characterisation of bars
• Evidence for Mature Bulges and an Inside-out Quenching Phase 3 Billion Years After the Big Bang
• Galactic Angular Momentum in the Illustris Simulation: Feedback and the Hubble Sequence
• The role of mergers and halo spin in shaping galaxy morphology
• Color Profiles of Spiral Galaxies: Clues on Outer-Disk Formation Scenarios
• Sparsity Averaging Reweighted Analysis (SARA): a novel algorithm for radio-interferometric imaging
• Dense cores in galaxies out to z=2.5 in SDSS, UltraVISTA, and the five 3D-HST/CANDELS fields
• Satellite abundances around bright isolated galaxies
• The influence of diffuse scattered light I. The PSF and its role to observations of the edge-on galaxy NGC 5907
• A physically motivated definition for the size of galaxies in an era of ultra-deep imaging
• The Fornax Deep Survey with VST. VIII. Connecting the accretion history with the cluster density
• The Sloan Digital Sky Survey extended point spread functions
• Frequency and properties of bars in cluster and field galaxies at intermediate redshifts
• Expectations of the size evolution of massive galaxies at $3\le z\le 6$ from the TNG50 simulation: the CEERS/JWST view
• NIHAO XXI: The emergence of Low Surface Brightness galaxies
• ERGO-ML I: Inferring the assembly histories of IllustrisTNG galaxies from integral observable properties via invertible neural networks
• The edges of galaxies: Tracing the limits of star formation
• Are ultra-diffuse galaxies Milky Way-sized?
• CAVITY, Calar Alto Void Integral-field Treasury surveY and project extension
• The evolutionary pathways of disk galaxies with different sizes
• The Physical Origin of the Mass-Size Relation and Its Scatter of Disk Galaxies
• Dynamical structure of small bulges reveals their early formation in ΛCDM paradigm
• The AMIGA sample of isolated galaxies. XIV. Disc breaks and interactions through ultra-deep optical imaging
• A giant thin stellar stream in the Coma Galaxy Cluster
• Evolution of central galaxy alignments in simulations
• A physically motivated galaxy size definition across different state-of-the-art hydrodynamical simulations
• Deep view of the intracluster light in the Coma cluster of galaxies
• LIGHTS. A robust technique to identify galaxy edges
• The weak connection between the stellar haloes and merger histories of Milky Way-mass galaxies
• LIGHTS. The extended point spread functions of the LIGHTS survey at the LBT
• Bulgeless Evolution And the Rise of Discs (BEARD) II. The role of mergers in shaping the Milky Way analogues in TNG50

Cited by in corpus (2)

• Bulgeless Evolution And the Rise of Discs (BEARD) II. The role of mergers in shaping the Milky Way analogues in TNG50
• Bulgeless Evolution And the Rise of Discs (BEARD) III. A numerical simulation view of satellites around Milky-Way analogues