The Relation between Stellar and Dynamical Surface Densities in the Central Regions of Disk Galaxies

Abstract

We use the SPARC (Spitzer Photometry & Accurate Rotation Curves) database to study the relation between the central surface density of stars Sstar and dynamical mass Sdyn in 135 disk galaxies (S0 to dIrr). We find that Sdyn correlates tightly with Sstar over 4 dex. This central density relation can be described by a double power law. High surface brightness galaxies are consistent with a 1:1 relation, suggesting that they are self-gravitating and baryon dominated in the inner parts. Low surface brightness galaxies systematically deviate from the 1:1 line, indicating that the dark matter contribution progressively increases but remains tightly coupled to the stellar one. The observed scatter is small (~0.2 dex) and largely driven by observational uncertainties. The residuals show no correlations with other galaxy properties like stellar mass, size, or gas fraction.

Accepted for publication in ApJL (6 pages, 3 figures)

References in corpus (6)

• High-resolution dark matter density profiles of THINGS dwarf galaxies: Correcting for non-circular motions
• Color--Mass-to-Light Ratio Relations for Disk Galaxies
• Weighing Galaxy Disks with the Baryonic Tully-Fisher Relation
• Dark Matter Heating and Early Core Formation in Dwarf Galaxies
• Stellar Populations and the Star Formation Histories of LSB Galaxies: III. Stellar Population Models
• The Link Between Light and Mass in Late-type Spiral Galaxy Disks

Cited by in corpus (8)

• The Radial Acceleration Relation in Rotationally Supported Galaxies
• One Law To Rule Them All: The Radial Acceleration Relation of Galaxies
• SDSS-IV MaNGA: What Shapes The Distribution Of Metals In Galaxies? Exploring The Roles Of The Local Gas Fraction And Escape Velocity
• Universal MOND relation between the baryonic and `dynamical' central surface densities of disc galaxies
• Star formation triggered by galaxy interactions in modified gravity
• The local Tully-Fisher relation for dwarf galaxies
• Radial acceleration relation and dissipative dark matter
• The Dark Matter Distributions in Low-Mass Disk Galaxies. I. H$\alpha$ Observations Using the Palomar Cosmic Web Imager