UNIVERSITÄT ZU KÖLN

AG 2017 / Göttingen - Splinter Meeting: CCAT

CCAT-p (Cerro Chajnantor Atacama Telescope pathfinder) a new 6m off-axis submm telescope

(organized by Peter Schilke, Jürgen Stutzki, Universität zu Köln; Frank Bertoldi, Universität Bonn)

Date:  Tuesday, September 19th, 2017; 14:00 -- 16:30

Topic: Science Perspectives with CCAT-p     

CCAT-prime is a high-altitude submillimeter telescope dedicated to spectral line and panchromatic continuum surveys. This German-U.S.-Canadian project aims to map local star-forming regions and galaxies in [CI] and CO, trace the first population of star-forming galaxies through intensity mapping of their [CII] emission, and put new constraints on cosmology from galaxy cluster Sunyaev-Zel'dovich effect surveys. Our splinter invites the German community to discover CCAT-p capabilities and explore joint science opportunities, three years before the first data.

The CCAT-prime (CCAT-p) project featurest a 6-meter diameter telescope with a surface accuracy of 7-10 μm at 5600 meters elevation on Cerro Chajnantor in northern Chile. Implementation of a novel crossed-Dragone optical design (see figure below) will deliver a high-throughput wide-field-of-view telescope capable of illuminating >105 millimeter wavelength detectors (and many more at submm wavelengths) so that large areas of the sky can be scanned rapidly. The site at 5600 meters offers superb observing conditions yielding routine access to the 350 μm window as well as improved performance at longer wavelengths. Under the best conditions, observations in the 200 μm window will be possible. Additionally, deployment of CCAT-p on Cerro Chajnantor will provide operational experience at high altitude, thereby reducing risk for the future construction of a 25-meter (or larger) telescope at the high site.

The scientific goals of CCAT-p

The scientific goals of CCAT-p motivate its unique characteristics of wide-field, high throughput and high altitude location and are encompassed in major legacy programs:

GEco: “Galactic Ecology” studies in multiple spectral lines of the dynamic interstellar medium in a wide range of environments in the Milky Way, the Magellanic Clouds and other nearby galaxies;

Sunyaev-Zel'dovich effect (SZE): Measurement of the velocities, temperatures and transparencies of galaxy clusters via the Sunyaev-Zel’dovich effect to place new constraints on dark energy and the sum of the neutrino masses.

IM/EOR: Intensity mapping of the [CII] 158 mm line from star-forming galaxies in the epoch of reionization at redshifts of 6 to 8 to understand the topology and timescale of reionization.

GEvo: “Galaxy Evolution” studies of dusty star-forming galaxies far surpassing the Herschel results in number counts and directly resolving (and characterizing) the population of faint sources responsible for most of the FIR counts/background;

Furthermore, the crossed-Dragone design will establish the CCAT-p telescope as a next-generation Cosmic Microwave Background (CMB) platform, offering the capability to map the sky 10 times faster than current CMB facilities. While other CMB efforts focus on wavelengths longer than one mm, the availability of simultaneous submm imaging offered by CCAT-p will allow more precise removal of foreground dust contamination of the CMB signal. With its large flat focal plane, CCAT-p will be ready to exploit the anticipated future advances in detector arrays.

CCAT-p is being constructed under the framework established for the original CCAT project as a partnership of Cornell, the Universities of Bonn and Cologne and CATC, a consortium of Canadian academic institutions. Faculty and staff at several international institutes including in Chile are involved in science planning and instrumentation development. Discussions with additional potential partners are on-going.

CCAT-p construction will start in Q2 2017 and is expected to take four years to complete.

Optical layout of a crossed-Dragone telescope. Light from the sky is reflected first off a primary mirror, then off a nearly-flat secondary (almost as large as the primary) and finally off a smaller tertiary. The combination permits a high throughput of the light over a very wide field of view and delivers a flat focal plane that can accommodate hundreds of thousands to millions of detectors. From Niemack (2016, Appl. Optics, 55, pp. 1688-1696; arXiv:1511.04506).

The partners of the CCAT-prime project are: University Cornell, Ithaca, NY, USA; a Canadian consortium of 5 universities; the German CCAT consortium, consisting at, present, of Universität zu Köln, Institut für Astrophysik (former I. Physik. Institut), and Universität Bonn, Argelander Institut für Astronomie, and soon to join: the cosmology group at the MPI für Astrophysik, Garching, and Joe Mohr's group at the LMU, Munich (CHECK). Chilean astronomers will participate both in the instrumentation development in the science with CCAT-prime.

First-light instrumentation

Two instruments are in development for first light:

• a multiwavelenght large format camera tuned for several cosmology science applications
• a dual frequency band, large format heterodyne array to study the interstellar medium in the Milky Way and nearby galaxies in the submm- and sub-THz fine structure and molecular lines that are uniquely accesible from the high site.

Scope of the Splinter Meeting

The CCAT-prime project is going to be presented at the AG-Meeting in a highlight talk by Frank Bertoldi on Wednesday, September 20th. With the splinter meeting, we want to bring interested members of the astronomy community together to discuss the perspectives of CCAT-prime science. We anticipate to start with a series of short talks on the details of the telescope and the planned first-light instrumentation, followed by presenting the presently planned key-programm surveys in the four science areas listed above.

We invite interested members of the community, who are interested in the potential of CCAT-prime and have particular science cases in mind, to submit abstracts for talks and poster presentations. The goal of the splinter is to get an as broad as possible feedback from the community. The project is open for discussion of new and additional science cases, leading potentially also to additional collaborations and extending the CCAT partnership to new groups.

Agenda

Abstracts of the talks can be found on the AG Splinter Meetings page.

Related contributions:

Registration

Please register on the AG webpage http://ag2017.uni-goettingen.de/registration.php for this splinter meeting.

Contact

Main contact are Prof. Dr. F. Bertoldi, Universität Bonn, and   Prof. Dr. J. Stutzki, Universität zu Köln