UMD-Led Astronomy Team Shows Off Stunning Capabilities of NASA’s Most Powerful Space Telescope
Researchers Probed ‘Starburst Galaxy’ to Understand Conditions That Foster Stellar Birth
The James Webb Space Telescope, NASA's most capable space telescope, captured images of the starburst M82 galaxy in greater resolution than ever before, peering through layers of dust with its infrared camera. Below, an older Hubble Space Telescope image shows less detail the JWST photo.
Photo courtesy of NASA, ESA, CSA, STScI, Alberto Bolatto
A University of Maryland-led team of astronomers used NASA’s James Webb Space Telescope to survey Messier 82 (M82), a starburst galaxy that has long captivated scientists with its frenzy of star formation activity. Located 12 million light-years away in the constellation Ursa Major, M82 sprouts new stars 10 times faster than the Milky Way galaxy.
The team directed NIRCam, Webb’s near-infrared camera instrument, toward the starburst galaxy’s center to get a closer look at the physical conditions that foster the formation of new stars—observations that can also yield a deeper understanding of the early universe.
“M82 has garnered a variety of observations over the years because it can be considered as the prototypical starburst galaxy,” said astronomy Professor Alberto Bolatto, lead author of the study accepted for publication in The Astrophysical Journal. “Both NASA’s Spitzer and Hubble space telescopes have observed this target. With Webb’s size and resolution, we can look at this star-forming galaxy and see all of this beautiful, new detail.”
UMD astronomy Ph.D. student and study co-author Serena Cronin M.S. ’23 said she was amazed by these latest images of M82, which capture the galaxy’s core in glowing detail—down to the many speckles of space dust—and trace the shape of its galactic wind.
“There are so many bumps and wiggles that we couldn’t see before, even with Hubble, giving us a better view of the intricate structure of the galactic wind,” said Cronin. “Being one of the first people to lay eyes on these images reminded me of the sense of wonder and discovery that drew me toward this field in the first place.”
Star formation continues to be shrouded in mystery because the process can be hidden behind curtains of dust and gas. However, Webb’s infrared capabilities made it possible to peer through the murk using several wavelengths of light that highlight different properties of the galaxy.
While dark brown tendrils of heavy dust are threaded throughout M82’s glowing white core even in an infrared view, Webb’s NIRCam revealed a level of detail obscured in views from other telescopes. Closer to the center, small specks depicted in green denote concentrated areas of iron, most of which are remnants of supernovas. Small patches that appear red signify regions where molecular hydrogen is illuminated by a nearby young star’s radiation.
“This image shows the power of Webb,” said study co-author Rebecca Levy M.S. ’17, Ph.D. ’21 of the University of Arizona, Tucson. “Every single white dot in this image is either a star or a star cluster. We can start to distinguish all of these tiny point sources, which enables us to acquire an accurate count of all the star clusters in this galaxy.”
Looking at M82 in slightly longer infrared wavelengths, clumpy tendrils represented in red can be seen extending above and below the galaxy’s plane. These gaseous streamers are a galactic wind rushing out from the core of the starburst.
In part, Bolatto and his co-authors wanted to understand where this galactic wind originates and how hot and cold components interact within the wind. Webb’s NIRCam was able to trace the structure of the galactic wind by following a trail of polycyclic aromatic hydrocarbons (PAHs)—small dust grains that survive in cooler temperatures but are destroyed in hot conditions.
To the team’s surprise, Webb’s view of the PAH emission highlights the galactic wind’s fine structure—an aspect previously unknown. Depicted as red filaments, the emission extends away from the central region where the heart of star formation is located. Webb’s observations of M82 in near-infrared light spur further questions about star formation, some of which the team hopes to answer with additional Webb data, including that of another starburst galaxy. The team is also working on papers that will characterize the stellar clusters and correlations among wind components of M82.
The team will soon have spectroscopic observations of M82 from Webb ready for their analysis, as well as complementary large-scale images of the galaxy and wind. Spectral data will help astronomers determine accurate ages for the star clusters and provide a sense of timing for how long each phase of star formation lasts in a starburst galaxy environment.
UMD astronomy Professor Sylvain Veilleux, who also co-authored the study, said that he and Bolatto will continue to use Webb data to study the galactic winds of M82 and other objects.
“This is just the beginning since Alberto and I were recently awarded additional time on Webb to observe 10 objects with known, large-scale galactic winds, including M82,” Veilleux said. “We'll be mapping both the dust and the warm molecular gas, as well as the ionized gas entrained in large-scale galactic winds, to learn how closely they lie relative to each other.”
This article is based in part on a text by the Space Telescope Science Institute
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