An analytical model to kinematically identify thin discs in MaNGA galaxies

Meng Yang*, Anne-Marie Weijmans, Matthew A. Bershady, Michael Merrifield, Nicholas F. Boardman, Niv Drory

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

2 Downloads (Pure)

Abstract

We present an analytical model to identify thin discs in galaxies, and apply this model to a sample of SDSS MaNGA galaxies. This model fits the velocity and velocity dispersion fields of galaxies with regular kinematics. By introducing two parameters ζ related to the comparison of the model’s asymmetric drift correction to the observed gas kinematics and η related to the dominant component of a galaxy, we classify the galaxies in the sample as ”disc-dominated”, ”non-disc-dominated”, or ”disc-free” indicating galaxies with a dominating thin disc, a non-dominating thin disc, or no thin disc detection with our method, respectively. The dynamical mass resulting from our model correlates with stellar mass, and we investigate discrepancies by including gas mass and variation of the initial mass function. As expected, most spiral galaxies in the sample are disc-dominated, while ellipticals are predominantly disc-free. Lenticular galaxies show a dichotomy in their kinematic classification, which is related to their different star formation rates and gas fractions. We propose two possible scenarios to explain these results. In the first scenario, disc-free lenticulars formed in more violent processes than disc-dominated ones, while in the second scenario, the quenching processes in lenticulars lead to a change in their kinematic structures as disc-dominated lenticulars evolve to disc-free ones.
Original languageEnglish
Pages (from-to)2658–2669
JournalMonthly Notices of the Royal Astronomical Society
Volume504
Issue number2
Early online date15 Apr 2021
DOIs
Publication statusPublished - Jun 2021

Keywords

  • Galaxies:kinematics and dynamics
  • Galaxies: structure
  • Galaxies: disc
  • Galaxies: evolution

Fingerprint

Dive into the research topics of 'An analytical model to kinematically identify thin discs in MaNGA galaxies'. Together they form a unique fingerprint.

Cite this