Celebrate the Large and Long Program – Gemini Observations of Galaxies in Rich Early ENvironments (GOGREEN) Survey

Celebrate the Large and Long Program! is a series of blog posts which showcase the high-impact science under the Large and Long Program of Gemini Observatory.

What is the Large and Long Program?

The Large and Long Program (LLP) is one of five observing modes Gemini offers to users of our telescopes. These five modes categorize projects based on length and weather conditions required for the observations. Classically, Gemini accepts proposals on a six month basis and recipients awarded with observing time complete their observations within that given semester. Large and Long Programs, on the other hand, provide more flexibility for long term research and last anywhere from one to three years. This extended time frame promotes collaboration across communities and produces significant and high-impact science. Here, we ask past and present Large and Long Programs to share a little about their research and experience with Gemini Observatory.

Gemini Observations of Galaxies in Rich Early ENvironments (GOGREEN) Survey

1. Principal Investigator: Name and Affiliation?

Michael Balogh, Department of Physics and Astronomy, University of Waterloo

2. How would you describe your Large and Long Program?

We are obtaining spectra for hundreds of faint galaxies in 21 dense environments at 1<z<1.5.  This redshift range represents an epoch where the growth of large scale structure is just beginning to affect the evolution of galaxies.  With spectroscopy we will measure the ages, dynamics and growth rates (via star formation and mergers) for the low-mass galaxies that are the building-blocks for more massive cluster galaxies we observe today.  The homogeneous sample selection allows us to construct a robust statistical description of how the galaxy population has evolved over the last ~9.5 billion years.

3. Why is Gemini best suited for this research?

The GMOS instruments on Gemini are perfectly suited for this research, as the field of view is perfectly matched to the size of the dense structures we are observing (several Mpc at z~1).  The good red sensitivity of the detectors, with good response out to 1 micron, allows optical spectroscopy out to z=1.5.  The nod-and-shuffle capability allows us to obtain the residual-free sky subtraction that is critical to working at these red wavelengths, and also provides the ability to closely pack slits in the dense environments of galaxy clusters and groups.

4. What has been the best part of your experience with the Large and Long Program?

The opportunity to actually observe at Gemini, to see firsthand how the queue works and also to take advantage of the best weather conditions during priority visitor mode, has been a highlight of our Large and Long Program.

You can learn more about the GOGREEN Survey here.

Celebrate the Large and Long Program! is a series of blog posts which showcase the high-impact science under the Large and Long Program of Gemini Observatory.