2018/04/30 by Keoikantse Moses Mogotsi, Alessandro B. Romeo · 2 citations
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Galaxies: Formation, Evolution, Phenomena #Galaxy #Geometry #Physics #RADIUS #Radial velocity #Scaling #Sigma #Spiral (railway) #Spiral galaxy #Star (game theory) #Star formation #Stars #Stellar mass #Velocity dispersion #astro-ph.GA
paper · pdf · doi:10.1093/mnras/stz2370
MNRAS, in press
openalex created_date 2018/05/07 · arxiv created 2019/08/09 · openalex publication_date 2019/08/24 · arxiv updated 2019/09/25 · openalex updated_date 2026/08/05
Abstract The stellar velocity dispersion, σ, is a quantity of crucial importance for spiral galaxies, where it enters fundamental dynamical processes such as gravitational instability and disc heating. Here we analyse a sample of 34 nearby spirals from the Calar Alto Legacy Integral Field Area (CALIFA) spectroscopic survey, deproject the line-of-sight σ to σR and present reliable radial profiles of σR as well as accurate measurements of ⟨σR⟩, the radial average of σR over one effective (half-light) radius. We show that there is a trend for σR to increase with decreasing R, that ⟨σR⟩ correlates with stellar mass (M⋆) and tested correlations with other galaxy properties. The most significant and strongest correlation is the one with M⋆: ⟨ σ R⟩ ∝ M⋆ 0.5. This tight scaling relation is applicable to spiral galaxies of type Sa–Sd and stellar mass M⋆ ≈ 109.5–1011.5 M⊙. Simple models that relate σR to the stellar surface density and disc scale length roughly reproduce that scaling, but overestimate ⟨σR⟩ significantly.