Celebrate the Large and Long Program!

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 current Large and Long Programs to share a little about their research and experience with Gemini Observatory.

Addressing a Bias in the Relation Between Galaxies and Their Black Holes

Jonelle Walsh solves the mysteries of the universe observing at Gemini North Hilo Base Facility’s Control Room.

1. Principal Investigator: Name and Affiliation?

Jonelle Walsh, Texas A&M University

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

A major achievement in the field of extragalactic astronomy over the past 15 years has been the detection of supermassive black holes in nearby galaxies. Even though the black hole’s gravitational influence is limited to a very small region at the center of a galaxy, surprisingly the masses of black holes are set by the large-scale properties of the host galaxies. Our understanding of the underlying physics driving such relations is limited by the present sample of galaxies for which dynamical black hole masses have been measured. In particular, black hole mass determinations have been preferentially made in galaxies with small sizes at a given luminosity relative to the local galaxy population. Our Gemini Large and Long Program aims to address this bias by using the Near-infrared Integral Field Spectrometer (NIFS) assisted by Laser Guide Star (LGS) adaptive optics to weigh black holes in 31 nearby galaxies. Our program will yield a more complete census of local black holes in a wider range of galaxies with diverse evolutionary histories, thereby providing a deeper understanding of the co-evolution of black holes and galaxies.

3. Why is Gemini best suited for this research?

In order to dynamically detect supermassive black holes, we need to probe the central region of galaxies, where the gravitational potential from the black hole dominates over the rest of the galaxy. This region is quite small, even for nearby galaxies, and thus we require large telescopes, like Gemini, aided by adaptive optics. Furthermore, NIFS allows us to map out the motions of stars and gas as a function of spatial location very efficiently. NIFS behind adaptive optics has a proven track record in this field, contributing some of the most massive and least massive black hole mass measurements ever made, and everything in between. The Gemini Large and Long Program in particular affords us a unique and powerful opportunity to acquire a large, homogenous dataset that will be analyzed in a consistent way. Interpreting the results of black hole studies has been severely complicated by the many different instruments utilized and the widely varying analysis/modeling practices adopted.

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

We are a new Gemini Large Program, and just started obtaining observations during the 2016B semester. Thus far though, it has been fun to travel out to Gemini and observe through the priority visiting mode. Being able to make decisions real time and see how Gemini works behind the scenes has been very beneficial and educational.

Visit us next month to celebrate another Gemini Large and Long Program!