A unified scenario for the origin of spiral and elliptical galaxy structural scaling laws

Abstract

Elliptical (E) and spiral (S) galaxies follow tight, but different, scaling laws that link their stellar masses, radii, and characteristic velocities. Mass and velocity, for example, scale tightly in spirals with little dependence on galaxy radius (the "Tully-Fisher relation"; TFR). On the other hand, ellipticals appear to trace a 2D surface in size-mass-velocity space (the "Fundamental Plane"; FP). Over the years, a number of studies have attempted to understand these empirical relations, usually in terms of variations of the virial theorem for E galaxies and in terms of the scaling relations of dark matter halos for spirals. We use Lambda cold dark matter (LCDM) cosmological hydrodynamical simulations to show that the scaling relations of both ellipticals and spirals arise as the result of (i) a tight galaxy mass-dark halo mass relation and (ii) the self-similar mass profile of cold dark matter halos. In this interpretation, E and S galaxies of a given stellar mass inhabit halos of similar masses, and their different scaling laws result from the varying amounts of dark matter enclosed within their luminous radii. This scenario suggests a new galaxy distance indicator applicable to galaxies of all morphologies and provides simple and intuitive explanations for long-standing puzzles, such as why the TFR is independent of surface brightness, or what causes the "tilt" in the FP. Our results provide strong support for the predictions of LCDM in the strongly non-linear regime, as well as guidance for further improvements to cosmological simulations of galaxy formation.

17 pages, 13 figures. Accepted for publication in A&A

References in corpus (19)

• The EAGLE project: Simulating the evolution and assembly of galaxies and their environments
• Overview of the SDSS-IV MaNGA Survey: Mapping Nearby Galaxies at Apache Point Observatory
• K-corrections and filter transformations in the ultraviolet, optical, and near infrared
• The EAGLE simulations of galaxy formation: calibration of subgrid physics and model variations
• SPARC: Mass Models for 175 Disk Galaxies with Spitzer Photometry and Accurate Rotation Curves
• Ages and metallicities of early-type galaxies in the SDSS: new insight into the physical origin of the colour-magnitude and the Mg2-sigmaV relations
• Baryon effects on the internal structure of LCDM halos in the EAGLE simulations
• Scaling Relations of Spiral Galaxies
• A Survey of Galaxy Kinematics to z ~ 1 in the TKRS/GOODS-N Field. I. Rotation and Dispersion Properties
• The Tully-Fisher Relation and Its Residuals for a Broadly Selected Sample of Galaxies
• Feedback and the Structure of Simulated Galaxies at redshift z=2
• Satellite abundances around bright isolated galaxies
• The SAMI Galaxy Survey: Towards a unified dynamical scaling relation for galaxies of all types
• Size matters: abundance matching, galaxy sizes, and the Tully-Fisher relation in EAGLE
• The SAMI Galaxy Survey: Decomposed Stellar Kinematics of Galaxy Bulges and Disks
• The Spectroscopy and H-band Imaging of Virgo cluster galaxies (SHIVir) Survey: Scaling Relations and the Stellar-to-Total Mass Relation
• The SAMI Galaxy Survey: mass-kinematics scaling relations
• The Stellar Mass Fundamental Plane: The virial relation and a very thin plane for slow-rotators
• Mergers in Galaxy Groups. II. The Fundamental Plane of Elliptical Galaxies

Cited by in corpus (13)

• The Fundamental Plane in the LEGA-C Survey: unraveling the $M/L$ variations of massive star-forming and quiescent galaxies at $z\sim 0.8$
• MaNGA DynPop -- III. Stellar dynamics versus stellar population relations in 6000 early-type and spiral galaxies: Fundamental Plane, mass-to-light ratios, total density slopes, and dark matter fractions
• The SAMI -- Fornax Dwarfs Survey II: The Stellar Mass Fundamental Plane and the Dark Matter fraction of Dwarf Galaxies
• The weak dependence of velocity dispersion on disk fractions, mass-to-light ratio and redshift: Implications for galaxy and black hole evolution
• A common origin for the Fundamental Plane of quiescent and star-forming galaxies in the EAGLE simulations
• Probing galaxy evolution from $z=0$ to $z\simeq 10$ through galaxy scaling relations in three L-Galaxies flavours
• Intrinsic correlations of galaxy sizes in a hydrodynamical cosmological simulation
• A new framework for understanding the evolution of early-type galaxies
• Are there any extragalactic high speed dark matter particles in the Solar neighborhood?
• MaNGA DynPop. VII. A Unified Bulge-Disk-Halo Model for Explaining Diversity in Circular Velocity Curves of 6000 Spiral and Early-Type Galaxies
• Rotation curves and dynamical masses of MaNGA barred galaxies
• Accretion of Galaxies around Supermassive Black Holes and a Theoretical Model of the Tully-Fisher and M-Sigma Relations
• Is there a tilt in the fundamental (hyper)plane?