Space Telescope Imaging Spectrograph observations of the Interstellar velocity structure and chemical composition toward the Carina nebula

摘要

We have observed the O-type star CPD - 59°2603 in the Carina Nebula with the Space Telescope Imaging Spectrograph near-UV and far-UV high-resolution echelles, at a resolving power of ～ 110,000(FWHM) and S/M ～ 30. This sight line has complex velocity and excitation structure in the interstellar absorption lines, Corresponding to three distinct regions: very high velocity components formed within the nebula; a warm, Expanding H II region; and cool, low-velocity gas near the Sun. The Mg I and Mg II profiles show many Components, with velocities extending from -235 to + 123km s~-1.