Celebrate the Large and Long Program: A GNIRS Near-IR Spectroscopic Survey of z>5.7 Quasars

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.

A GNIRS Near-IR Spectroscopic Survey of z>5.7 Quasars

1. Principal Investigator: Name and Affiliation?

Yue Shen, University of Illinois at Urbana-Champaign

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

Our program focuses on the characterization of the physical properties of the first generation of supermassive black holes (SMBHs) at redshift greater than ~6. Powered by mass accretion onto these black holes, these objects are seen as luminous quasars when the Universe is less than one tenth of its current age, and are among the most distant objects within the reach of our most powerful observing facilities. It is the first systematic survey of these earliest SMBHs with dedicated spectroscopic observations conducted in the near-infrared wavelength range. With Gemini’s superb capabilities, we are putting together the largest near-IR spectroscopic data set for the these objects, and will study in detail their physical properties such as the mass of their black holes, the emission properties of these accreting SMBHs, and outflows traced by absorption features imprinted on their spectra. This sample will give us a glance of the earliest assembly of massive black holes in the Universe, and will shed light on their formation scenarios, as well as their co-evolution with their host galaxies at cosmic dawn.

3. Why is Gemini best suited for this research?

These highest-redshift quasars are extremely faint. To observe them in the near-infrared we really require large-aperture telescopes. Gemini and its near-IR spectragrah (GNIRS) provide one of the best facilities, and is publicly accessible, to perform such demanding observations. Indeed Gemini was used to provide near-IR spectroscopy for a handful of high-redshift quasars in the past, and with this new large Gemini program we are pushing this effort on a higher level.

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

I think the best part is the efficient query-mode execution of the program by the Gemini team. For our program with a large sample of objects spread over the year to be observed, the query-mode observations make it a lot easier to obtain the data and minimize weather impact, and the Gemini team has been great in executing the program for us.