J,H and K maps of the Galactic centre region - II. Qualitative aspects of the interstellar absorption

Abstract

J (1.25 μm), H (1.65 μm) and K (2.2 μm) maps of a 2°×1°(α×δ) region of the sky including the galactic centre and having a resolution of a few arcsec are presented. While almost the entire J map is dominated by heavy interstellar extinction, those at H and K show progressively more detail of the inner regions of the Galaxy. Even at K, however, much of the map is dominated by dark clouds, some of which show fine filamentary structure. Most of these clouds can be associated with foreground molecular material having low radial velocity. The high-velocity clouds observed at radio wavelengths toward the galactic centre are not in general apparent and are probably embedded within the dense stellar distribution.