Spectroscopy lies at the heart of astrophysical inference. Our understanding of the origin and
evolution of the cosmos critically depends on our ability to make quantitative measurements of
physical parameters such as the total mass, distribution, motions, temperatures, and composition
of matter in the Universe. Detailed information on all of these properties can be gleaned from
high-quality spectroscopic data. For distant objects, some of these properties (e.g., motions
and composition) can only be measured through spectroscopy.
Ultra-violet (UV) spectroscopy provides some of the most fundamental diagnostic data necessary
for discerning the physical characteristics of planets, stars, galaxies, and interstellar and
intergalactic matter. The UV offers access to spectral features that provide key diagnostic information
that cannot be obtained at other wavelengths.
COS will help answer some fundamental questions:
- What is the large-scale structure of matter in the Universe?
- How did galaxies form out of the intergalactic medium?
- What types of galactic halos and outflowing winds do star-forming galaxies produce?
- How were the chemical elements for life created in massive stars and supernovae?
- How do stars and planetary systems form from dust grains in molecular clouds?
- What is the composition of planetary atmospheres and comets in our Solar System (and beyond)?