by The James Webb Space Telescope (JWST) has zoomed into the heart of the Cigar Galaxy, a region of space ablaze with an explosive bout of star birth.
This stellar galaxy, known as Messier 82 (also M82), has a dense but turbulent environment at its core, which could give scientists a clearer picture of how stars are born en masse, and how extreme environments shape the galaxies around them.
Located about 12 million light-years away in the constellation Ursa Major, M82 is forming stars 10 times faster than our own relatively quiet galaxy, the Milky Way. The team imaged the core of this starburst galaxy with JWST’s Near-Infrared Camera (NIRCam) to investigate the conditions driving the formation of baby stars.
Related: The James Webb Space Telescope hints at exoplanets forming in an infant star system
“M82 has received a variety of views over the years because it can be considered the prototypical stellar galaxy,” Alberto Bolatto, team leader and University of Maryland researcher, said in a statement. “The Spitzer and Hubble space telescopes saw this target.
“With the size and resolution of JWST, we can look at this star-forming galaxy and see this beautiful new detail.”
sHow the JWST can see straight through constellations
Star formation is common throughout the cosmos, but it has been able to retain an air of mystery because the gas and dust that make up the raw material necessary for star formation effectively encapsulates the process.
Although gas and dust are very efficient at absorbing visible light, however, infrared light is able to slip through this material. That means, with its powerful and sensitive infrared view of the cosmos, the JWST is the perfect instrument to get right to the heart of star birth.
The NIRCam images collected by Bolatto and his colleagues also benefited from a special method that prevented the bright infant stars at the heart of M82 from overwhelming the instrument.
JWST’s shortwave infrared light image of M82 shows dark, brownish-red tendrils of dust weaving their way through the white smoke, the cigar, the core of M82’s glare. Small green specks in the image show regions of iron left over from supernova explosions of now-dead massive stars. Patches that appear red indicate areas where molecular hydrogen is being heated by radiation from young stars.
“This image shows the power of the JWST,” University of Arizona team member and scientist Rebecca Levy said in the statement. “Each white dot in this image is a star or star cluster. We can start to distinguish all these tiny sources, allowing us to get an accurate count of all the star clusters in this galaxy .”
Galactic wind of a cigar smoker
When JWST’s NIRCam imaged the core of M82 in infrared light, the star-studded region took on a stunning new look. Suddenly, gaseous streams of galactic winds, extending further from the previously observed galactic core, almost resembled a network of blood vessels extending from a biological heart rather than a galactic heart.
This galactic wind is driven by star formation and the supernova death of older stars. Like the blood of life pumped through blood vessels in the human body, the galactic wind moves elements around that facilitate galactic growth through further star formation, which has a strong effect on the body around it.
NIRCam was able to trace the structure of these galactic winds as they release volatile chemical molecules called polycyclic aromatic hydrocarbons (PAHs). Because PAHs are small dust grains that survive in cool regions but are destroyed at warmer temperatures, this showed how cold and warm components interact within the wind.
The team did not expect to reveal the fine structure of the galactic wind in M82 — nor did they expect any similarities in the shape of the PAH emission and the structure of the tendrils of hot, ionized gas.
“It was unexpected to see that PAH emission is similar to ionized gas,” Bolatto explained. “PAHs shouldn’t last very long when exposed to a strong radiation field, so maybe they’re being replenished all the time. It challenges our theories and shows us that further investigation is required.”
RELATED STORIES:
— The James Webb Space Telescope shows confirmation of the 1st rocky planet
— James Webb Space Telescope’s groundbreaking study of planet-forming disks hints at future exoplanet discoveries
— The James Webb Space Telescope reveals the atmosphere of an alien planet that never existed before
The team hopes that further JWST observations of M82 and other star galaxies may help answer some lingering questions about star birth. The scientists will also combine these new images with complementary large-scale images of the Cigar Galaxy and its Galactic wind.
A spectrum of light from this galaxy should help astronomers determine the exact ages of the star clusters in M82. This, in turn, could reveal how long each stage of star formation lasts in interstellar environments.
“With these amazing JWST images and our upcoming spectra, we can study exactly how strong winds and shock fronts from young stars and supernovae can shake up the gas and dust from which new stars are forming removal,” staff member and the European Space Agency (ESA). ) said the scientist Torsten Böker in the statement. “A detailed understanding of this ‘feedback’ cycle is important for theories about how the early universe changed because compact galaxies like the one in M82 were very common at high redshift.”
The team’s research has been accepted for publication in The Astrophysical Journal.
