UW astronomy professor Mike Brotherton will be decrypting the brightest parts of the universe from one of the darkest peaks of Hawaii with a $800,000 grant from the National Science Foundation.
Brotherton and his University of North Texas colleague will collect data from the Gemini North Observatory, which sits atop a 4,200-foot dormant volcano on the island of Hawaii. Stable, dry, and rarely cloudy weather allow for Gemini North, and its twin telescope in Chile, some of the most superb viewing conditions in the field of astronomy. Brotherton aims to use this tropical vantage point to shed light on some of the brightest objects in the universe, quasars.
Quasars are, by far, some of the oldest objects in the galaxy. At the base of each quasar is a supermassive black hole, around which, a swirling disk of gas rotates. This gas feeds the black hole and is so luminous that it often outshines the surrounding galaxy.
Brotherton’s innovation in the study of quasars deals with how these objects are observed. Traditionally quasars were identified by optical spectra, the limited number of things that can be seen with human eyes. Unfortunately for humans, large bright galactic phenomena often become “red-shifted,” meaning that the light they radiate shifts to the infrared spectrum, before it gets to Earth and thus can no longer be seen with the naked eye. Brotherton’s research hopes to make up for this biological deficit by using new techniques to analyze infrared spectra.
“We’ve gotten vast quantities of data using one technique, and we know almost nothing about quasar properties using this other technique,” Brotherton said in a release. “This is a step in remedying that. Nobody has systematically been gathering infrared spectra for large numbers of these objects. What we’re really doing is jumping ahead to get a large sample with uniform data and selection.”
Quasars often sit at the center of galaxies, making them a key actor in the great cosmological play that astronomers seek to observe. Around a million quasars have been identified, but due to the issues associated with observations scientists have only been able to study a fraction of those bodies more closely. Brotherton plans to study around 400 quasars with infrared imaging and in doing so hopes to read some of the script of galactic evolution quasars have played a leading role in.
“Today, quasars barely exist,” Brotherton said. “The supermassive black holes are still around, but they are not being fed or fueled the way they used to be. When these quasars were really around and common and having a huge influence on the universe, was a long time ago.”
It’s not very often that humans have the opportunity to view galactic history, and less often they get financial support for the effort. With the National Science Foundation’s grant, Brotherton will have the opportunity to pioneer new techniques and to uncover some of the well-lit ancient secrets of the galaxy, all while seated atop a Hawaiian volcano.
