Credit: Chris Taylor/CSIRO
"They are believed to be the end stage of the evolution of a very massive star, and every galaxy hosts one in its centre," says Suryashree Aniyan. She's talking about supermassive black holes, which could be several billion times heavier than our Sun.
Aniyan spends her summer analysing data collected by the world's most sensitive infrared telescope - NASA's Wide-Field Infrared Explorer (WISE) - as part of national science agency CSIRO's Vacation Scholarship Program at the Centre for Astronomy and Space Science (CASS) in Sydney.
She says the gravity of black holes is so strong, that not even light escapes - so they cannot be seen. "That makes it very difficult to study them." To learn more, researchers have to look at the motion of surrounding stars or analyse jets of radio waves, which some black holes emit.
Another problem with supermassive black holes is that they are incredibly far away, which is why their signals are very weak once they reach our Solar System. In fact, what Aniyan is looking at has happened several million years ago - that's how long it took for the signals to reach the WISE telescope. "It's like looking back in time," she says.
In order to find these distant, invisible space objects, Aniyan combined the infrared signals collected by WISE with another dataset from a radio telescope and repeatedly filtered them using the criteria believed to indicate the presence of black holes.
What this procedure came up with is a list of seven objects that the researchers are convinced are supermassive black holes. What makes Aniyan so excited about these is that this information "brings us one step closer to understanding the universe that we know so little about. It helps us to understand the physics of how things work in the universe".
After completing an undergraduate degree in her native India, majoring in physics, mathematics and computer science, Aniyan came to Australia last year to do her Masters in astrophysics at the University of Adelaide in South Australia. She now loves having the opportunity to get to know the day-to-day work at a research institution like the CSIRO. "I find the whole thing so fascinating," she says. "I have learned so much. In university you learn about all these things theoretically but you don't quite get how to analyse data from a radio telescope and how you would connect that to discovering something completely new."
