2019/05/29 by Dilyar Barat, Francesco D'Eugenio, Matthew Colless +17 · 1 citation
Physics and Astronomy · #astro-ph.GA
paper · pdf · doi:10.1093/mnras/stz1439
14 pages, 8 figures, Accepted 2019 May 22. Received 2019 May 18; in original form 2019 January 6
arxiv created 2019/05/29 · arxiv updated 2019/05/31
We use data from the Sydney-AAO Multi-object Integral-field spectroscopy (SAMI) Galaxy Survey to study the dynamical scaling relation between galaxy stellar mass M_* and the general kinematic parameter SK = √K Vrot2 + σ2 that combines rotation velocity Vrot and velocity dispersion σ. We show that the log M_* - log SK relation: (1)~is linear above limits set by properties of the samples and observations; (2)~has slightly different slope when derived from stellar or gas kinematic measurements; (3)~applies to both early-type and late-type galaxies and has smaller scatter than either the Tully-Fisher relation (log M_* - log Vrot) for late types or the Faber-Jackson relation (log M_* - logσ) for early types; and (4)~has scatter that is only weakly sensitive to the value of K, with minimum scatter for K in the range 0.4 and 0.7. We compare SK to the aperture second moment (the `aperture velocity dispersion') measured from the integrated spectrum within a 3-arcsecond radius aperture (σ3′′). We find that while SK and σ3′′ are in general tightly correlated, the log M_* - log SK relation has less scatter than the log M_* - log σ3′′ relation.