The Cosmic Origins Spectrograph (COS) is an instrument aboard the Hubble Space Telescope, designed primarily to study the large-scale structure of the universe, its origins, and its evolution. Here are some detailed insights into COS:
History and Development
Functionality and Capabilities
- COS is a high-resolution ultraviolet spectrograph, optimized for observing faint, distant objects in the ultraviolet spectrum, which is largely absorbed by Earth's atmosphere.
- Its primary science objectives include:
- Studying the cosmic web of gas, which is the raw material for stars and galaxies.
- Probing the composition and physical conditions of intergalactic medium (IGM).
- Understanding the reionization history of the universe.
- Exploring the formation and evolution of galaxies by observing their gaseous environments.
- COS has two channels:
- The Far Ultraviolet (FUV) Channel, covering wavelengths from 90 to 215 nm.
- The Near Ultraviolet (NUV) Channel, which operates between 170 to 320 nm.
- Its sensitivity is significantly higher than that of previous Hubble spectrographs, allowing for the observation of fainter objects and shorter exposure times.
Scientific Achievements
- COS has made significant contributions to our understanding of the universe:
- It has detected a large number of Lyman-Alpha Forest systems, providing clues about the distribution and composition of intergalactic gas.
- It has helped map the cosmic web, revealing the structure of dark matter through its gravitational effects on visible matter.
- COS has observed the atmospheres of exoplanets, analyzing their composition to infer details about their formation and potential habitability.
Technical Specifications
- Resolution: COS achieves a spectral resolution of R~15,000 to 20,000, depending on the mode.
- Field of View: It has a very narrow field of view, designed for point source observations.
- Sensitivity: COS is about 10 to 70 times more sensitive than earlier Hubble UV spectrographs.
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