CanariCam Science Team – Meeting in Madrid, 9/12

10.4 METER GRAN TELESCOPIO CANARIAS (GTC)

 

Two years into the commissioning process of the world’s largest infrared camera and telescope combination, the CanariCam Science Team met in Madrid, Spain, for two days in September to assess its progress and future plans. The meeting was held at facilities made available by the official Spanish government research agency, the Consejo Superior de Investigaciones Cientificas (CSIC).

Currently installed on the 10.4 meter Gran Telescopio Canarias (GTC) in the Canary Islands, CanariCam is a mid-infrared (MIR) camera designed to explore the areas around supermassive black holes, circumstellar disks where new planets may be forming, and brown dwarfs. When combined with the world’s largest optical-infrared telescope, CanariCam is at the cutting edge of MIR explorations.

UF Professor Telesco with CanariCam Installed on GTC

Designed by a team of scientists at the University of Florida, led by UF astronomer Charles Telesco, CanariCam has been put through its initial paces and passed with flying colors. Valuable GTC time has been allotted to the instrument. “We’ve got the instrument, and we’ve got the telescope time. Let’s do science!” Professor Telesco told the thirty assembled astronomers from around the world.

The University of Florida is a 5% partner in the GTC. UF is a world leader in astronomical instrumentation, and by partnering with the GTC and for having built CanariCam, UF’s Astronomy Department obtains valuable observation time to conduct its own research.

CanariCam was installed on the GTC in 2010, and has been undergoing rigorous commissioning procedures. Many aspects of CanariCam’s capabilities have been commissioned, but the marriage of CanariCam to the GTC is a work in progress, with several current issues still being ironed out. For example, strong winds (called “Calima”) in the nearby Sahara lift fine sand particles into the air and blow them across the Atlantic. Infrared imaging demands extremely clean mirrors, creating the necessity of regularly cleaning the 10.4 meter telescope, comprised of 36 separate mirrors working as one. The GTC staff astronomers present at the Madrid meeting discussed new cleaning techniques and timing to address this issue. Improving the fast guiding capabilities of the GTC is also an area where new improvements are forthcoming.

CanariCam Being Installed At Naysmyth Focus of GTC

So, what new science can we expect from CanariCam now that it has started to accumulate astrophysical data? One of its new capabilities is in the area of polarimetry, the measurement of polarization in the infrared wavelengths reaching the camera. CanariCam is the first dual-beam MIR polarimeter available at such a large telescope for astrophysical research. This mode of the camera is nearly fully commissioned.

The light from astronomical sources can become polarized (where the light “waves” become oriented in specific directions) for several reasons. For example, polarization can occur from light emitted by warm dust particles oriented like compass needles by strong magnetic fields near a star or other heating source, or by scattering of IR radiation by dust particles in disks surrounding a star. By examining the orientation and change in polarization with wavelength, astronomers can extract new information about the actual structure of distant objects. As Chris Wright, an Australian member of the team said, “Without polarization, half the information that a photon can potentially provide is thrown away.” What role do magnetic fields play in regulating star formation? Polarimetry can not only answer such questions, but also peer through obscuring layers to observe the dust near stars. CanariCam polarimetry is working as promised so far, and according to Chris Wright “opens up whole new areas for study.”

In order for the scientific community at large to use CanariCam on the GTC, it will be necessary to provide “pipelines” of software that will give astronomers the tools needed to reduce and analyze the data obtained. Dan Li, a graduate student from UF, and Omaira Gonzalez Martin, a scientist with the Institute for Astrophysics in the Canary Islands (IAC), each described the interfaces they had developed to reduce imaging and spectrographic data from CanariCam. The assembled scientists discussed ways, including development of such “pipelines,” to encourage involvement from the astrophysical community.

Chris Packham, one of the designers of CanariCam, described some preliminary polarimetry results, examining Cygnus A, an Active Galactic Nucleus (AGN) thought to be a supermassive black hole about 600 million light years from us. It was the faintest object CC has looked at so far, and showed some unusual polarization. Packham emphasized that much more data is needed before drawing any conclusions, and several of the scientists present at the meeting suggested ways of eliminating certain types of observational errors or biases in the results.

As the only non-professional present at the meeting, I was struck by the way in which real science is not someone shouting “Eureka! Look what I found!” Instead, it is a constant process of looking for errors, testing and retesting conclusions, attempting to falsify the data in as many ways as possible.

CCST Attendees in Madrid

Team member and prominent astrophysicist Rafael Rebolo of the IAC summarized the current status of CanariCam for the assembled team. “CanariCam meets the design requirements.” As further commissioning moves forward, he urged the team to help streamline the process of data reduction in order to encourage greater involvement from the astrophysical community. As current team projects begin to acquire science, data and results, “we can show what a breakthrough CanariCam is.” He suggested preliminarily planning a community-wide meeting some time in late 2013 or 2014, to highlight to the astrophysical community what CanariCam is doing, and what it can do.

As Professor Telesco said at the beginning of the two day meeting, “Let’s do science!”