Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey

The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) was the largest project ever done with the Hubble Space Telescope. It used almost 60 full days of observing time between 2010 and 2013. During this time, two special cameras on the telescope, called WFC3 and ACS, looked far into space to study how galaxies formed and grew.

CANDELS helped scientists learn about the very first galaxies that appeared in the universe. These were the earliest seeds of structure, appearing less than one billion years after the Big Bang. By studying these ancient galaxies, researchers could understand how the universe changed over time.

This project gave us amazing pictures and information about the early Universe and how galactic evolution happened. It showed scientists how galaxies like our own Milky Way began their journey billions of years ago.

Science goals

CANDELS aimed to study how galaxies changed in the early universe. It looked at more than 250,000 galaxies to see how they developed. Another goal was to find special explosions called Type Ia supernovae that happened a very long time ago. These explosions help scientists understand how the universe works. The survey also used special camera time to look at a particular area of the sky when the Hubble Space Telescope had continuous viewing opportunities.

Main article: redshifts
Main articles: deep imaging, Type Ia, supernova, standard candles, cosmology, UV/Vis, GOODS

Facility and instruments

CANDELS used the Wide Field Camera 3, a special camera that sees light that we cannot see with our eyes. This camera was added to the Hubble Space Telescope in May 2009. It worked together with another camera that sees light we can see, called the Advanced Camera for Surveys. Together, they helped scientists study galaxies from different kinds of light.