Spitzer Wide-area Infrared Extragalactic Survey
SWIRE • Research Project • Operational
The Spitzer Wide-area Infrared Extragalactic survey is one of six very large programs undertaken as Legacy surveys during the first year of flight of the Spitzer Space Telescope. SWIRE has imaged nearly 50 square degrees (equal to the area of 250 full moons) divided among 6 different directions on the sky, detecting over 2 million galaxies by their heat radiation, some of them over 11 billion light years away.
As a survey, SWIRE's science goals are very broad and can encompass many different individual investigations. This large survey was designed with two general goals in mind. The first general goal of SWIRE is simply to observe a very large patch of sky with Spitzer, so that SWIRE can detect large numbers of galaxies across large expanses of space. Galaxies don't lie evenly across space, instead they are grouped into clusters, and clusters of clusters, or in long thin filaments, and there are large areas devoid of galaxies, called, imaginatively, voids. These structures can be extremely large across, so to map them out astronomers must chart vast areas, and that was what SWIRE was designed to do in the infrared with Spitzer. Galaxies have been charted across similar volumes before at other wavelengths, but in the infrared previous surveys have been much shallower, or much smaller.
SWIRE's second general goal is to detect galaxies far enough away that they can reveal how the Universe looked when it was 1/2 it's current age, or even younger. Since light travels at a finite speed, we see astronomical objects as they looked when the light set off, not as they are the moment that the light arrives at Earth. For the sun that time delay is only 8 minutes, but for the nearest galaxy it's over a million years! So doing astronomy is like using a time machine - to see things as they were a long time ago, just look further away! With SWIRE, we can see galaxies over 5 billion years old, or more.
The nucleus of the SWIRE team is the original Wide-field InfraRed Explorer - WIRE science team - a project for which IPAC provided science operations and data analysis. The SWIRE data team is based at IPAC, and IPAC hosts the SWIRE website.
The SWIRE team includes many past and present IPAC scientists and staff, including the PI Carol Lonsdale, Tim Conrow, Tracy Evans, Fan Fang, Joann O'Linger, Russ Laher, Frank Masci, Deborah Padgett, David Shupe, Jason Surace, and Kevin Xu.
SWIRE data is hosted by IRSA at IPAC, including the raw observations from Spitzer in the Spitzer Heritage Archive, and enhanced data products and tools.