Michael Zemcov

The Epoch of Reionization

A major focus of my current research is observation of the epoch of reionization. This was the era during which the first population of stars in the Universe, seeded by the same over-densities visible in the cosmic microwave background radiation, ionized the neutral hydrogen then ubiquitously present in the Universe. The epoch of reionization is at the forefront of current cosmological research, and what little is known about it suggests it was virtually complete at the earliest times we are able to probe with today's best optical instruments. The details of the process, such as when it began, how long it took, and what class of sources produced it, are not known. The image below shows our current understanding of the process of reionization, which began roughly 500 million years after the big bang and was complete about 500 million years later.

A promising way to study the epoch of reionization is using the fluctuations it causes in the infra-red background. Several of the projects I am currently involved with are searching for these fluctuations, which will allow a much better understanding of the generation of the first galaxies in the Universe and the processes which led to them.

The Cosmic Infrared Background Experiment (CIBER) is a sounding rocket borne experiment which is optimized to search for the signatures of reionization in the near infrared background. With its first flight in early 2009 and second in the middle of 2010, the CIBER payload has been extremely successful. The continuation of this project, CIBER-2, is currently being designed and will fly in 2013. In addition, we are working on a small space mission to measure the near infrared fluctuations from a distant vantage point in the solar system such as Saturn named ZEBRA. The future of reionization studies in the infrared is promising.

CIBER Photos

At work in the clean room at Wallops Flight Facility during payload integration.

The CIBER flight team with the rocket on the rail the day before our 2009 launch.

Lifting off into the dark New Mexico sky.