THE LYMAN ALPHA REFERENCE SAMPLE. III. PROPERTIES OF THE NEUTRAL ISM FROM GBT AND VLA OBSERVATIONS

• We present new Hi imaging and spectroscopy of the 14 UV-selected star-forming galaxies in the Lyman Alpha Reference Sample (LARS), aimed for a detailed study of the processes governing the production, propagation, and escape of Ly alpha photons. New Hi spectroscopy, obtained with the 100 m Green Bank Telescope (GBT), robustly detects the Hi spectral line in 11 of the 14 observed LARS galaxies (although the profiles of two of the galaxies are likely confused by other sources within the GBT beam); the three highest redshift galaxies are not detected at our current sensitivity limits. The GBT profiles are used to derive fundamental Hi line properties of the LARS galaxies. We also present new pilot Hi spectral line imaging of five of the LARS galaxies obtained with the Karl G. Jansky Very Large Array (VLA). This imaging localizes the Hi gas and provides a measurement of the total Hi mass in each galaxy. In one system, LARS 03 (UGC 8335 or Arp 238), VLA observations reveal an enormous tidal structure that extends over 160 kpc from the main interacting systems and that contains >10(9) M-circle dot of Hi. We compare various Hi properties with global Ly alpha quantities derived from Hubble Space Telescope measurements. The measurements of the Ly alpha escape fraction are coupled with the new direct measurements of Hi mass and significantly disturbed Hi velocities. Our robustly detected sample reveals tentative correlations between the total Hi mass and linewidth, and key Ly alpha tracers. Further, on global scales, these data support a complex coupling between Ly alpha propagation and the Hi properties of the surrounding medium.

Ämnesord

NATURVETENSKAP  -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Astronomy, Astrophysics and Cosmology (hsv//eng)

Nyckelord

galaxies: ISM

galaxies: kinematics and dynamics

galaxies: starburst

radio lines: galaxies

Astronomy

astronomi

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)