Skip to main content
The Lyman alpha reference sample. VII. Spatially resolved Hα kinematics (2015)
  • Edmund C. Herenz
  • Pieter Gruyters
  • Ivana Orlitova
  • Matthew Hayes
  • John M Cannon
"We present integral field spectroscopic observations with the Potsdam Multi Aperture Spectrophotometer of all 14 galaxies in the z∼0.1 Lyman Alpha Reference Sample (LARS). We produce 2D line of sight velocity maps and velocity dispersion maps from the Balmer α (Hα) emission in our data cubes. These maps trace the spectral and spatial properties of the LARS galaxies' intrinsic Lyα radiation field. We show our kinematic maps spatially registered onto the Hubble Space Telescope Hα and Lyman α (Lyα) images. Only for individual galaxies a causal connection between spatially resolved Hα kinematics and Lyα photometry can be conjectured. However, no general trend can be established for the whole sample. Furthermore, we compute non-parametric global kinematical statistics -- intrinsic velocity dispersion σ0, shearing velocity vshear, and the vshear0 ratio -- from our kinematic maps. In general LARS galaxies are characterised by high intrinsic velocity dispersions (54\,km\,s−1 median) and low shearing velocities (65\,km\,s−1 median). vshear0 values range from 0.5 to 3.2 with an average of 1.5. Noteworthy, five galaxies of the sample are dispersion dominated systems with vshear0<1 and are thus kinematically similar to turbulent star forming galaxies seen at high redshift. When linking our kinematical statistics to the global LARS Lyα properties, we find that dispersion dominated systems show higher Lyα equivalent widths and higher Lyα escape fractions than systems with vshear0>1. Our result indicates that turbulence in actively star-forming systems is causally connected to interstellar medium conditions that favour an escape of Lyα radiation." [Abstract from]
Publication Date
November 17, 2015
Citation Information
Edmund C. Herenz, Pieter Gruyters, Ivana Orlitova, Matthew Hayes, et al.. "The Lyman alpha reference sample. VII. Spatially resolved Hα kinematics" (2015)
Available at: