The Lyman Alpha Reference Sample XV. Relating Ionised Gas Kinematics with Lyman-$\alpha$ observables

• DOI: 10.48550/arxiv.2406.03956
• Publication Date: 2024-06-06
• Authors: E. C. Herenz; A. Schaible; Peter Laursen; Axel Runnholm; Jens Melinder; Alexandra Le Reste; Matthew Hayes; G. Östlin; John M. Cannon; Genoveva Micheva; M. Roth; Kanak Saha
• Keywords: Alpha (finance); Sample (material)

Gas kinematics affect the radiative transfer and escape of hydrogen Lyman-$\alpha$ (Ly$\alpha$) emission from galaxies. We investigate this interplay empirically by relating ionised gas 42 galaxies in extended Ly$\alpha$ Reference Sample with their fractions, $f_\rm{esc}$, equivalent widths, $\rm{EW}_\rm{Ly\alpha}$, luminosities, $L_\rm{Ly\alpha}$. To aim we use PMAS integral-field spectroscopic observations Balmer-$\alpha$ line. calculate shearing velocities, $v_\rm{shear}$, intrinsic velocity dispersions, $\sigma_0^\rm{obs}$ (empirically corrected for beam-smearing effects), as global kinematical measures each galaxy. The sample is characterised highly turbulent motions more than half shows dispersion dominated kinematics. uncover clear trends between observables statistics. discuss statistically importance $\sigma_0^\rm{obs}$, $v_\rm{shear}/\sigma_0^\rm{obs}$ regulating comparison to other galaxy parameters. It emerges that dominating parameter $\rm{EW}_\rm{Ly\alpha}$ important nebular extinction, covering fraction, ionising photon production efficiency $f_\rm{esc}$. A simple scenario where starburst age simultaneously turbulence, $f_\rm{esc}$ does not find support our observations. However, show small scale distribution dust appears be influenced turbulence some In observational result how theoretically expected play a significant role modulating (abridged)