VERITAS Education Website | adlerplanetarium.org
Welcome!
The Very Energetic Radiation Imaging Telescope Array System (VERITAS), located at the Fred Lawrence Whipple Observatory near Amado, Arizona, U.S.A., is an observatory built to study gamma rays from extreme astrophysical phenomena in the Universe. VERITAS is now scanning the night sky searching for remnants of exploded stars, distant active galaxies, powerful gamma ray bursts, and evidence of mysterious Dark Matter particles. This website is here to help you join the exploration!
If you’re a student, teacher, collaborator, or just someone interested in the fascinating field of gamma-ray astronomy, you’ll find useful information, lesson guides, photographs, and other multimedia right here!
Newsflash
Mt. Hopkins, Ariz. — VERITAS, a new array for very-high-energy gamma-ray astronomy, has just begun observations of gamma-ray air showers at the Smithsonian Institution’s Fred Lawrence Whipple Observatory in southern Arizona, U.S.A. A "first light" celebration will mark the event on April 28, 2007, at Whipple Observatory.
Meet a VERITAS Scientist!
Trevor Weekes
Trevor Weekes is a leader of the branch of astrophysics devoted to the study of very high-energy gamma rays, or TeV gamma rays. A senior researcher at the Harvard-Smithsonian Center for Astrophysics, Dr. Weekes pioneered the techniques that the VERITAS telescope uses to detect TeV gamma rays. He spoke with Christine Minerva, an educator at the Adler Planetarium & Astronomy Museum in Chicago, about the VERITAS project.
Please come back soon to read a full article about Dr. Weekes and his work on the VERITAS project.
CM: What is your role on the VERITAS project?
TW: I was the originator of the project now known as VERITAS. I have led the Smithsonian Gamma-Ray Group for the last 30 years, and about 25 years ago came up with the concept of imaging the Cherenkov light emitted by gamma rays using arrays of phototubes in the focal plane of large optical reflectors. We’ve developed the imaging technique and it is now used in the VERITAS project as well as in several observatories around the world.
In 1996, I made a proposal to build an array of very-high energy gamma-ray detectors, which we now call VERITAS, in an internal proposal to the Smithsonian Astrophysical Observatory. We formed a collaboration of ten institutions and submitted the proposal to the Department of Energy and the National Science Foundation.
CM: What is so exciting about the VERITAS project?
TW: VERITAS is an important instrument for the detection of very high-energy gamma rays. These gamma rays are very different than the ones used in medicine or come from radioactive decay, or even those that are detected by space-based telescopes. They are particularly interesting because they have such very high energies and can only be made on earth with great difficulty, for example, at the great high-energy physics laboratories like Fermilab. When we detect a very high-energy gamma-ray source, we know that is must be something exotic with the physical conditions necessary for the acceleration of high energy particles.
Because the gamma rays are very energetic, we don’t expect them to come from the Sun, planets, or normal galaxies. We do believe they might come from cosmic sources such as pulsars, exploding stars (supernovae), galaxies with massive black holes at their cores, so-called active galactic nuclei, and gamma-ray bursters, which give off short bursts of gamma-ray radiation. When we observe such sources, we are looking at unique cosmic laboratories where there are exotic physics processes going on.
CM: How did you first become interested in astronomy?
TW: I did a PhD at University College, Dublin, and joined a cosmic-ray project in 1962. I’m a physicist rather than astronomer, and entered it with the thought to pursue cosmic ray physics. Like many of the people in this field, I’ve never taken a course in astronomy. Many of the people in the field have come from high-energy physics groups. Our major funding comes from high-energy physics programs of the Department of Energy and the National Science Foundation, so these agencies consider that we are doing high-energy physics but in a cosmic setting.
CM: What were your motivations to pursue techniques for ground-based gamma ray astronomy?
TW: I started this in Ireland where the funding was [pretty] minimal, so we looked to pursue a technique that could be done pretty economically. At that time, all of the work in this field was done on low budgets using World War II surplus equipment; Only recently has it become necessary to use more sophisticated detectors.
CM: The Whipple 10-meter telescope operated for more than 20 years, from 1968 until 1989, before discovering TeV gamma rays from the Crab Nebula. What were those early years like? What was the key to its success?
TW: Actually, the Whipple telescope operated from 1968-1978, and at that stage the project was closed down because no sources had been detected. It was reopened in 1982, when we developed a new technique to take a picture of each flash of light, which allowed us greater sensitivity. The early years were extremely frustrating because there was no guarantee that there were any sources of very high-energy gamma rays.
CM: Why did you continue with the work when you could not guarantee that there were any sources of high-energy gamma rays?
TW: Lack of imagination rather than anything else! There was some stubbornness because I thought that the project had been closed down prematurely, so I wanted to prove that the effort that had gone into it was worth it.
CM: What have been the most important or personally interesting developments in astrophysics since your career began?
TW: In our particular field, I’d say that the discovery of very high-energy gamma rays FROM active galactic nuclei was the most exciting because the sources are highly variable and can increase significantly over a time-scale of minutes; Hence when we observe them we never know what to expect. On a global level, the discovery of gamma ray bursts was one of the most revolutionary discoveries in all of astrophysics because it opened up the astronomy of sources with lifetimes of just seconds.
CM: Why should the public care about VERITAS and gamma ray astronomy?
TW: There is no science as intriguing to the layperson as the science of astronomy, and hence we have a perfect tool for teaching physics. The astronomy of very high-energy gamma rays that are far beyond the detection of the human eye is intriguing and broadens our knowledge of the Universe.
CM: Is there anything you would like to add about VERITAS or your role in the project?
TW: I think this technique [for detecting gamma rays] is particularly interesting for students because it involves so many aspects of physics: atmospheric physics, space physics, particle interactions, high-energy physics, high-speed electronics, optics, and analysis of large databases. It has the promise of exciting new discoveries in astrophysics and physics.