ARCHIVE Most of us know that our solar system exists inside of a galaxy called the Milky Way. Our solar system is based around a star, a.k.a, the sun, and this star is one of an estimated 100 to 400 billion stars inside of the Milky Way. This idea alone is beyond our imagination—indeed, we are but a tiny spec in this one galaxy. And yet, in the universe, which is expanding, there are an estimated 170 billion galaxies.*
“Astronomers at one point in their careers sooner or later realize how little and almost nothing we are in the universe,” said Marina Vika, a post-doctoral researcher at Carnegie Mellon University in Qatar who has been working with a QNRF-funded team on a project to markedly improve the study of galaxies. “The size of the universe … I don’t think that the human mind can really comprehend it. We can understand it in numbers and in math but the actual size is something outside of what we are able to interpret.”
Over the past 50 years, research on galaxies has steadily begun to boom in tandem with the increasing power of telescopes. With this improved resolution, scientists discovered that there were too many galaxies to measure and analyze one by one. So researchers called upon computer technology to help handle the massive task.
“In the last 10 years people have developed a more automatic way of doing things, like researching galaxies stars and planets, because the amount of data is increasing so much that it’s impossible to analyze all the data that we get from satellites and telescopes with the old manual methods,” Dr. Vika said. “It takes too many human hours to do this, so we need computers to analyze this data and we have to train them. We have to create and refine the software so that they will keep up with what we are able to gather.”
Most galaxies comprise two basic features: a central spheroid and an outer disk. The study of galaxies involves determining the finer points of their structure—including features like disks, rings, bulges, spiral arms, nuclei, cores and streams. These qualities help determine its age, size, rate of growth and other properties.
The research team is an international collaboration including Dr. Vika, Dr. Steven Bamford of the University of Nottingham, UK, Dr. Boris Haeussler of the University of Oxford, UK, and Prof. Alex Rojas of Carnegie Mellon University in Qatar. Their project, named MegaMorph, has adapted existent software in order to develop a new technique that creates more sophisticated models for galaxies.
“I study how the structure changes,” Dr. Vika explained. “Do all the galaxies have the same components? And if so, are they the same size? This information has been studied for the last 20 years or so, but in the last five years we found out—by using different types of telescopes that allow us to see beyond the visible spectrum—that some galaxies are totally changing size and sometimes even shape when observed at different wavelengths, and the reason they are changing shape is because we can now see different stellar populations due to the additional wavelengths available through the different wavelength-focused lenses. For example studying the blue light emitted by a galaxy you can focus on young stars, but if you observe the red light coming from a galaxy, you may see older stars.”
NGC 1068 is a spiral galaxy about 48 million light-years away. Like most spiral galaxies, its main structure features a central bulge, an outer disk and spiral arms. At high resolution, astronomers can identify a faint ring substructure. These five pictures of the same galaxy are taken with one telescope using five different passbands.
The team based their work on existing technology that was released about ten years ago and has been cited, tested and approved to analyze galaxies based on single wavelengths, or ‘bands.’ Their research is geared toward expanding this traditional technique so that it can process multiple bands at once.
“So now, we can automatically study each galaxy according to multiple bands of light information,” Dr. Vika said. “For each galaxy, we have a better overall image of how this galaxy behaves because we are using multiple images of the same galaxy. Those multiple images are not taken with the same telescope. With this new method the user is not limited on how many images they can use. It allows images from totally different wavelengths, e.g. ultra violent, optical or near infrared, to be combined in order to create a model that can change based on wavelengths.”
The team has been working on their new software and analyzing technique to make it as generic as possible, Dr. Vika said. This will allow anyone in the field to adapt it to their own research. So far, they have demonstrated and published their success in peer-reviewed journals and presented their progress at international conferences. When the software is finalized, they will make it available to the public, only requesting that their team and QNRF be credited as the developers and supporters, respectively.
The Middle East is the home of the scientists who hundreds of years ago made the first observations about our galaxy. Until recently, Qatar was not focused, academically, on astronomy. And yet, as a discipline, it contributes greatly to the scientific culture. When Dr. Vika arrived, she found that, although they may not have been exposed to astronomy before, students were interested in the subject.
"As Qatar seeks to develop in the realm of technology—among other things—it's important that we include the "pure sciences" in that endeavor. Because pure sciences, like physics, astronomy, or mathematics, establish and develop ways of thinking that can be applied to other fields,” she said. “Some people may say that studying the structure of galaxies doesn’t really have a direct benefit to Qatar. However, having an innovative method that has the Qatar Foundation signature may spark interest in the next generation related to how this science can be applied, perhaps even in other fields.”
Dr. Vika and her team expressed many thanks to QNRF for their support in making the idea of the MegaMorph project a reality.
* “The Fabric of Reality” by David Deutsch
Automated Measurement of Galaxy Morphology