Molekülwolken in hohen galaktischen Breiten

Extended and very weak reflection nebulae have been observed at high galactic latitudes. Goerigk et al. (1983) have studied a nebula in the constellation Draco. The 21 cm line of atomic hydrogen was found to be in positional coincidence with the optical brightness distribution. The studied nebula, called 'Draco Nebula' or 'Dracula', is also a reflection nebula. On the basis of various observed characteristics of Dracula, including a deficiency of ionized hydrogen, it is concluded by Goerigk et al., that a predominant amount of hydrogen nuclei is present in the form of H2. The present investigation is concerned with the observation of CO, which can be used as an indicator for molecular hydrogen. The obtained results are presented in a graph. It can be seen that CO is generally found at the locations with the strongest H I emission. This correlation, however, does not apply with respect to every detail. It appears rather that the best correlation is found between CO emission and the brightness of the reflected light.