I’m a high energy physicist. I work at Clemson University in Clemson, South Carolina, as a Professor in the Astrophysics Department. My focus is on the high energy Universe. You could also call me a gamma ray astronomer because I look at phenomena in the sky – supernovae – to make sense of the physical processes that cause them. As a result of supernova explosions, we have gamma radiation. But gamma rays are also generically associated with nuclear phenomena. Gamma rays are generated by radioactive atoms and in collisions of ions in nuclear explosions.

You know that the electromagnetic spectrum is divided into broad categories of gamma rays, X-rays, ultraviolet, optical, infrared, millimeter and radio. These categories are arranged in decreasing order of energy and increasing order of wavelength. Gamma ray photons have the most energy and smallest wavelengths of any other energy in the EM spectrum, in the range of 100 eV to 100,000 eV and wavelengths of 0.01 nanometers and 1012 nanometers.

Space scientists – physicists and astronomers – study different phenomena in space to understand different physical properties. Gamma ray astronomers talk about very high frequency and very short wavelengths. In fact, we prefer to think in terms of energy. People who work in the infrared region like to think in terms of wavelengths. Astronomy that looks at lower energy levels is usually interested in atomic physics, but in the gamma ray spectrum the energy scale is at the MeV region, so we are talking about things that happen in nuclei. Gamma ray astronomy is really about answering questions about nuclear physics using the incredibly violent, incredibly high-temperature laboratory that is space.

Why does it matter that we look at the sky in different energy bands? Let me give you an analogy. Do you like art? Let’s say you go to a museum to understand your favorite artist – from Salvador Dali to Rembrandt. But the museum you go to makes you look at all of these beautiful paintings wearing glasses that only let through red light. All you can see is the red in the picture, not all of the other colors or details that aren’t in the red region. How much do you think you would understand about that work of art if you only could see part of it?

When we look at the sky through all of its various energies, when we have the actual multiwavelength coverage, then all of a sudden you can appreciate the whole picture. It’s a very narrow picture if you’re looking at the optical region, or ultraviolet only, or just the blue in a painting. It’s by having all the information that you figure out the story of that phenomenon in space. Just like with art, if you don’t get to see all the colors, you’re not getting the complete picture. Of course our eyes are limited to seeing only a narrow band of visible light, the spectrum of the rainbow. But there is so much more to see with telescopes and instruments that can detect various energy levels.

This is what multiwavelength astronomy is all about – getting a complete picture. In order for us to understand the world, astronomers want to see phenomena in space at all energy bands.
Each of these energy bands have unique characteristics that contribute to the big picture.
And as I said, I like explosives, so I am into the high energy phenomena like nucleosynthesis, supernovae, and gamma ray bursts.