NASA engineer Ernie Wright looks on as the first six flight ready James Webb Space Telescope's primary mirror segments are prepped to begin final cryogenic testing at NASA's Marshall Space Flight Center. NASA/MSFC/David Higginbotham

 

Both Angela Adamo and Emil Rivera-Thorsen from the SU Astronomy department had proposals chosen from the more than 1000 that were submitted asking for time in the first cycle of telescope operations.
Emil will use his time to study the Suburst Arc, a galaxy whose contents have been magnified by gravitational lensing. He says, "One consequence of Einstein's general theory of relativity is that not only matter, but also light, is affected by gravity. The enormous masses of large galaxies or galaxy clusters can act like natural "telescopes", magnifying objects behind them by tens or even hundreds of times.

The Sunburst Arc is a spectacular example of such a distant, gravitationally magnified galaxy. But it is also a rare type of galaxy that leaks extreme-ultraviolet radiation, capable of ionizing hydrogen, into intergalactic Space. This radiation usually gets absorbed by the interstellar gas in a galaxy before it can escape, unless some process has created passageways out. We don't know *how* this happens, but we do know it must have happened much more often in the Universe's childhood - enough to ionize almost all gas in the Universe in a few hundred years.

Studying this escape is difficult. If a galaxy is close enough to study in detail, its ionizing radiation is extremely difficult to capture. The Milky Way blocks most of it, and our instruments are very insensitive to what remains. For more distant galaxies, cosmic expansion stretches the wavelength of the ionizing photons enough to solve these problems, but then the detail is lost to distance --- unless a gravitational lens system happens to come between and
magnify it for us. Ironically, then, the mind boggling distance helps us get a closer look at the ionizing escape than we can hope to get even in our own intergalactic neighborhood."

Angela will observe a sample of diverse galaxies in our local Universe. She says, "the formation of stars is a key event in galaxies and has fundamental implications for our Universe. With the JWST-FEAST program we will address some fundamental questions about the nurseries where stars form. These nurseries are dens and obscured at optical wavelengths. But the James Webb Telescope has IR glasses, it can see through dust and dens cold gas at a spatial resolution that is 20 times better that its predecessor, the Spitzer Space observatory. What do stellar cradles look like in other galaxies? How fast are newly born stars clearing their surroundings? For the first time we will be able to study stellar nurseries beyond our Milky Way and get a more complete and comprehensive picture of how and where stars form in the universe."