April 8, 2017
Timothy Hamilton has been awarded telescope time at the Gemini Observatory in Hawaii.
Timothy Hamilton, Professor of Physics and Coordinator of the Clark Planetarium at Shawnee State University, has been awarded telescope time at the Gemini Observatory in Hawaii.
Hamilton is part of a research collaboration group led by Dr. Dave Turnshek, University of Pittsburgh, that focuses on studying star formation by observing cold gas clouds made up of hydrogen, which is essential in the formation of new stars. The only way astronomers can study these formations are with the help of telescopes capable of seeing millions or billions of light years away, which means the images themselves are millions or billions of years old due to the time it takes for light to travel and reach the telescope’s visibility. In this way, they can see backward in time to study the universe when it was younger.
“In each case, once we find which galaxy contains the cold gas clouds, we can determine what type of galaxy it is. It could be a spiral-shaped, elliptical, or an irregular type of galaxy, and we can find out where in the galaxy the gas cloud is,” said Hamilton.
By combining pictures taken with the Hubble Space Telescope and chemical spectra measured with the Very Large Telescope (VLT), Hamilton’s team has been looking at distant quasars (very bright galaxies with massive black holes that can be seen across the universe). But one bright galaxy seen with the Hubble wasn’t picked up at all with the VLT, even though the VLT saw many fainter galaxies.
“We believe this galaxy that the VLT can’t see is glowing from hydrogen more than starlight, and its hydrogen cloud is absorbing light and re-emitting it. Because of the prism used with the Hubble, the glowing hydrogen appears shifted off to the side from the galaxy’s actual position in the sky, tricking us into aiming the telescope in the wrong direction, which is why we could not see it the second time,” Hamilton said.
The goal is to determine if this is a “Lyman-Alpha Emitter” galaxy, named for the color of ultraviolet light emitted by its hydrogen, which forms numerous stars rapidly, and if the energy given off by the young stars causes the hydrogen gas to blast their skies with ultraviolet radiation. Many have been detected at great distances since the ultraviolet light is “redshifted” and becomes visible, but they are hard to find once they are closer since the Earth’s atmosphere blocks ultraviolet.
Hamilton hopes to have a confirmation that the galaxy his team found is a Lyman-Alpha Emitter once the staff at the Gemini Observatory send the team their pictures. The Gemini Telescope is used for special data collection, such as the one Hamilton requires, due to its Integral Field Unit camera, a new technology based on a camera that measures the chemical spectrum of the light in every pixel of the image. The information gathered helps researchers in determining the motion of the galaxy, volume of gas in question, and a better account on distance.
“If we are correct in our findings, this galaxy is the closest Lyman-Alpha Emitter that has been seen. It would be an important galaxy to study the relationship between cold hydrogen gas and newly-forming stars because it gives us the ability to see what the universe could have been when it was much younger, smaller and more crowded,” said Hamilton.