GALEX Galaxy Evolution Explorer By Jessica Hauss GALEX
GALEX: Galaxy Evolution Explorer By: Jessica Hauss
GALEX
What is GALEX? l l A small explorer class mission under NASA’s Structure and Evolution of the Universe Division Led by California Institute of Technology
Scientific Goals l Understand the evolution of star formation in galaxies from the early universe to the present. l Compare near-by galaxies to older galaxies in order to better understand how galaxies evolve. l Map a large section of the Universe
Three Basic Properties 1. Speed of light 2. Distribution of galaxies l The expansion of the Universe
Spectrum
UV light
Galaxies Spiral – M 74 Elliptical - M 87 Irregular – IC 10
What we learn from UV light? l l l Star formation rates Distance Shape of galaxy Gas content How galaxies cluster How these change with time
Surveys l All-Sky Imaging Survey – l Deep Sky Imaging – l A unique ultraviolet map of the entire sky A measure of the ultraviolet light from galaxies more than 80% of the way back to the beginning. A Survey of the 200 closest galaxies in ultraviolet.
Spectroscopic Surveys l Wide-field Spectroscopic Survey – l Medium-deep Spectroscopic Survey – l Shows how UV emission is related to star formation rates and how much gas and dust is present. Shows nearby star-forming galaxies so we can compare them to older galaxies. Deep Spectroscopic Survey – Show the faintest galaxies with the least star formation.
Cartwheel Galaxy
Cartwheel Galaxy
Cartwheel Galaxy
Cartwheel Galaxy
Cartwheel Galaxy
Thanks… l www. galex. caltech. edu
- Slides: 23