Abstract |
The spectral absorption features due to interstellar ices, especially H2O and CO2 ices in the near-IR, provide us crucial information on present and past interstellar environments, and thus the evolutionary histories of galaxies. Before AKARI, however, few detections of the ices were reported for nearby galaxies. The AKARI's unique capability of near-IR spectroscopy with high sensitivity enables us to systematically study ices in nearby galaxies.
We explored many near-IR spectra of 520 pointed observations carried out within the framework of the AKARI nearby galaxy project. As a result, out of 200 nearby galaxies, we have significantly detected the H2O ices from 27 galaxies and the CO2 ices from 5 galaxies. We find that the CO2 ice is more compactly distributed near the galactic center than the H2O ice. In this presentation, we show initial results of our systematic studies on ices in nearby galaxies, and discuss their physical implications for the interstellar environments of the galaxies. |