Comparing Ultraviolet and Infrared-Selected Starburst Galaxies in Dust
  Obscuration and Luminosity
  We present samples of starburst galaxies that represent the extremes
discovered with infrared and ultraviolet observations, including 25 Markarian
galaxies, 23 ultraviolet luminous galaxies discovered with GALEX, and the 50
starburst galaxies having the largest infrared/ultraviolet ratios. These
sources have z < 0.5 and cover a luminosity range of ~ 10^4. Comparisons
between infrared luminosities determined with the 7.7 um PAH feature and
ultraviolet luminosities from the stellar continuum at 153 nm are used to
determine obscuration in starbursts and dependence of this obscuration on
infrared or ultraviolet luminosity. A strong selection effect arises for the
ultraviolet-selected samples: the brightest sources appear bright because they
have the least obscuration. Obscuration correction for the ultraviolet-selected
Markarian+GALEX sample has the form log[UV(intrinsic)/UV(observed)] =
0.07(+-0.04)M(UV)+2.09+-0.69 but for the full infrared-selected Spitzer sample
is log[UV(intrinsic)/UV(observed)] = 0.17(+-0.02)M(UV)+4.55+-0.4. The relation
of total bolometric luminosity L_{ir} to M(UV) is also determined for
infrared-selected and ultraviolet-selected samples. For ultraviolet-selected
galaxies, log L_{ir} = -(0.33+-0.04)M(UV)+4.52+-0.69. For the full
infrared-selected sample, log L_{ir} = -(0.23+-0.02)M(UV)+6.99+-0.41, all for
L_{ir} in solar luminosities and M(UV) the AB magnitude at rest frame 153 nm.
These results imply that obscuration corrections by factors of two to three
determined from reddening of the ultraviolet continuum for Lyman Break Galaxies
with z > 2 are insufficient, and should be at least a factor of 10 for M(UV)
about -17, with decreasing correction for more luminous sources.
