Detection of HI in Emission in the Lyman Alpha Emitting Galaxy Haro 11
  We present the first robust detection of HI 21 cm emission in the blue
compact galaxy Haro 11 using the 100m Robert C. Byrd Green Bank Telescope
(GBT). Haro 11 is a luminous blue compact galaxy with emission in both Lyman
Alpha and the Lyman continuum. We detect (5.1 $\pm$ 0.7 $\times$10$^8$)
M$_{\odot}$ of HI gas at an assumed distance of 88 Mpc, making this galaxy HI
deficient compared to other local galaxies with similar optical properties.
Given this small HI mass, Haro 11 has an elevated M$_{H2}$/M$_{HI}$ ratio and a
very low gas fraction compared to most local galaxies, and contains twice as
much mass in ionized hydrogen as in neutral hydrogen. The HI emission has a
linewidth of 71 kms$^{-1}$ and is offset 60 kms$^{-1}$ redward of the optical
line center. It is undergoing a starburst after a recent merger which has
elevated the star formation rate, and will deplete the gas supply in $<$ 0.2
Gyr. Although this starburst has elevated the SFR compared to galaxies with
similar HI masses and linewidths, Haro 11 matches a trend of lower gas
fractions toward higher star formation rates and is below the general trend of
increasing HI mass with increasing luminosity. Taken together, our results
paint Haro 11 as a standard low-mass galaxy that is undergoing an unusually
efficient star formation episode.
