UC physicist turns galaxies into magnifying lens

The study was published in the journal Nature Astronomy.

Bayliss, an assistant professor in UC’s McMicken College of Arts and Sciences, collaborated with an international team of researchers in his former position at the Massachusetts Institute of Technology. The team used the famous Hubble space telescope for optical images along with the Spitzer space telescope, which provides infrared imaging. But arguably the most important tool was the Chandra X-ray Observatory, which captures X-rays from black holes and distant stars.

Unlike light from distant stars, X-rays don’t penetrate Earth’s atmosphere. So NASA in 1999 launched Chandra high above the Earth. How high? The International Space Station, which you can see at night with the naked eye, circles about 240 miles above the Earth. Chandra flies in an elliptical orbit as far as 86,500 miles away from Earth.

University of Michigan associate professor Keren Sharon, a co-author of the study, said gravitational lensing allows researchers to study galaxies that would be too faint to observe otherwise.

“We've been taking advantage of ‘cosmic telescopes’ to study faint galaxies in long wavelengths for a couple of decades now,” she said.

“Being able to observe them in the X-ray regime opens a window for new discoveries and enables detailed studies of intrinsically faint X-ray sources that would otherwise have to wait for the next generation of telescopes.”

Massive dying stars eventually collapse, ejecting their matter in a supernova explosion before becoming neutron stars or black holes. Despite vast improvements in astronomical observation, comparatively little is known about the origins of these massive stars and how they might influence each other, Bayliss said.

“We’re hoping to understand how young stars form in the distant universe,” he said.