The Lyman alpha Reference Sample: II. HST imaging results, integrated
  properties and trends
  We report upon new results regarding the Lya output of galaxies, derived from
the Lyman alpha Reference Sample (LARS), focusing on Hubble Space Telescope
imaging. For 14 galaxies we present intensity images in Lya, Halpha, and UV,
and maps of Halpha/Hbeta, Lya equivalent width (EW), and Lya/Halpha. We present
Lya and UV light profiles and show they are well-fitted by S\'ersic profiles,
but Lya profiles show indices systematically lower than those of the UV (n
approx 1-2 instead of >~4). This reveals a general lack of the central
concentration in Lya that is ubiquitous in the UV. Photometric growth curves
increase more slowly for Lya than the FUV, showing that small apertures may
underestimate the EW. For most galaxies, however, flux and EW curves flatten by
radii ~10 kpc, suggesting that if placed at high-z, only a few of our galaxies
would suffer from large flux losses. We compute global properties of the sample
in large apertures, and show total luminosities to be independent of all other
quantities. Normalized Lya throughput, however, shows significant correlations:
escape is found to be higher in galaxies of lower star formation rate, dust
content, mass, and several quantities that suggest harder ionizing continuum
and lower metallicity. Eight galaxies could be selected as high-z Lya emitters,
based upon their luminosity and EW. We discuss the results in the context of
high-z Lya and UV samples. A few galaxies have EWs above 50 AA, and one shows
f_escLya of 80%; such objects have not previously been reported at low-z.
