  Motivated by recent detection of transiting high-density super-Earths, we
explore the detectability of hot rocky super-Earths orbiting very close to
their host stars. In the environment hot enough for their rocky surfaces to be
molten, they would have the atmosphere composed of gas species from the magma
oceans. In this study, we investigate the radiative properties of the
atmosphere that is in the gas/melt equilibrium with the underlying magma ocean.
Our equilibrium calculations yield Na, K, Fe, Si, SiO, O, and O$_2$ as the
major atmospheric species. We compile the radiative-absorption line data of
those species available in literature, and calculate their absorption opacities
in the wavelength region of 0.1--100~$\mathrm{\mu m}$. Using them, we integrate
the thermal structure of the atmosphere. Then, we find that thermal inversion
occurs in the atmosphere because of the UV absorption by SiO. In addition, we
calculate the ratio of the planetary to stellar emission fluxes during
secondary eclipse, and find prominent emission features induced by SiO at
4~$\mathrm{\mu m}$ detectable by Spitzer, and those at 10 and 100~$\mathrm{\mu
m}$ detectable by near-future space telescopes.
