Webb Probes an Extreme Starburst Galaxy

Starburst galaxy M82 was observed by the Hubble Space Telescope in 2006, which showed the galaxy’s edge-on spiral disk, shredded clouds, and hot hydrogen gas. The James Webb Space Telescope has observed M82’s core, capturing in unprecedented detail the structure of the galactic wind and characterizing individual stars and star clusters.

The Webb image is from the telescope’s NIRCam (Near-Infrared Camera) instrument. The red filaments trace the shape of the cool component of the galactic wind via polycyclic aromatic hydrocarbons (PAHs). PAHs are very small dust grains that survive in cooler temperatures but are destroyed in hot conditions. The structure of the emission is similar to that of the ionized gas, suggesting PAHs may be replenished from cooler molecular material as it is ionized.

Astronomers used the James Webb Space Telescope to look toward M82’s center, where a galactic wind is being launched as a result of rapid star formation and subsequent supernovas. Studying the galactic wind can offer insight into how the loss of gas shapes the future growth of the galaxy.

This image from Webb’s NIRCam (Near-Infrared Camera) instrument shows M82’s galactic wind via emission from sooty chemical molecules known as polycyclic aromatic hydrocarbons (PAHs). PAHs are very small dust grains that survive in cooler temperatures but are destroyed in hot conditions. The structure of the emission resembles that of hot, ionized gas, suggesting PAHs may be replenished by continued ionization of molecular gas.

In this image, light at 3.35 microns is colored red, 2.50 microns is green, and 1.64 microns is blue (filters F335M, F250M, and F164N, respectively).

A team of astronomers used NASA’s James Webb Space Telescope to survey the starburst galaxy Messier 82 (M82), which is located 12 million light-years away in the constellation Ursa Major. M82 hosts a frenzy of star formation, sprouting new stars 10 times faster than the Milky Way galaxy. Webb’s infrared capabilities enabled scientists to peer through curtains of dust and gas that have historically obscured the star formation process.

This image from Webb’s NIRCam (Near-Infrared Camera) instrument shows M82’s center in an unprecedented level of detail. With Webb’s resolution, astronomers can distinguish small, bright compact sources that are either individual stars or star clusters. Obtaining an accurate count of the stars and clusters that compose M82’s center can help astronomers understand the different phases of star formation and the timelines for each stage.

In this image, light at 2.12 microns is colored red, 1.64 microns is green, and 1.40 microns is blue (filters F212N, 164N, and F140M, respectively).