Sharpness of star-forming image matches expected resolution of Webb Space Telescope — ScienceDaily


NASA’s James Webb Space Telescope is still more than a year from launching, but the Gemini South telescope in Chile has provided astronomers a glimpse of what the orbiting observatory should deliver.

Using a wide-field adaptive optics camera that corrects for distortion from Earth’s atmosphere, Rice University’s Patrick Hartigan and Andrea Isella and Dublin City University’s Turlough Downes used the 8.1-meter telescope to capture near-infrared images of the Carina Nebula with the same resolution that’s expected of the Webb Telescope.

Hartigan, Isella and Downes describe their work in a study published online this week in Astrophysical Journal Letters. Their images, gathered over 10 hours in January 2018 at the international Gemini Observatory, a program of the National Science Foundation’s NOIRLab, show part of a molecular cloud about 7,500 light years from Earth. All stars, including Earth’s sun, are thought to form within molecular clouds.

“The results are stunning,” Hartigan said. “We see a wealth of detail never observed before along the edge of the cloud, including a long series of parallel ridges that may be produced by a magnetic field, a remarkable almost perfectly smooth sine wave and fragments at the top that appear to be in the process of being sheared off the cloud by a strong wind.”

The images show a cloud of dust and gas in the Carina Nebula known as the Western Wall. The cloud’s surface is slowly evaporating in the intense glow of radiation from a nearby cluster of massive young stars. The radiation causes hydrogen to glow with near-infrared light, and specially designed filters allowed the astronomers to capture separate images of hydrogen at the cloud’s surface and hydrogen that was evaporating.

An additional filter captured starlight reflected from dust, and combining the images allowed Hartigan, Isella and Downes to visualize how the