GALEX science objectives
FROM NASA PRESS KIT
Posted: April 24, 2003
The primary objective of the Galaxy Evolution Explorer is to learn what factors trigger star formation inside galaxies; how quickly stars form, evolve and die; and how heavy chemical elements
form in stars.
Additional goals include:
- Determining how fast stars are forming inside each galaxy
- Determining when and how the stars we see today formed
- Creating the first map of the ultraviolet universe
- Helping scientists find and understand ultraviolet bright quasars. These objects can serve as
background sources for the Hubble Space Telescope and FUSE as it probes the gases from
which galaxies form stars
To accomplish its objectives, the Galaxy Evolution Explorer will conduct eight surveys, grouped into two broad categories - a local universe investigation and a star formation history investigation.
The local universe investigation includes the following four surveys:
- All-sky imaging survey - will look at the entire sky and develop a comprehensive catalogue
of ultraviolet galaxy images, useful to map the distribution of star formation within the local
universe
- Nearby galaxy survey - will study about 150 nearby galaxies that are familiar to scientists to
understand how stars formed in individual galaxies
- Wide-field spectroscopic survey - will analyze the light wavelengths of galaxies in a wide
swath of the sky
- Medium spectroscopic survey - will examine the light properties of galaxies within a narrower
portion of the sky
The star formation history investigation will take information gathered by the local universe investigation and apply it to more distant galaxies by looking further back in time. It includes the following four surveys:
- Deep imaging survey - will look at a portion of the sky to study the distribution of star formation in the deep universe
- Deep spectroscopic survey - will look for the most distant galaxies
- Ultra-deep imaging survey - will look as deep as possible at a very small portion of the sky
- Medium imaging survey - will study star formation in galaxies beyond our local cosmic
neighborhood, but not as deep as the deep imaging survey
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