New observations from NASA, ESA and CSA’s James Webb Space Telescope suggest that the Milky Way’s central region became enriched with metals—elements heavier than hydrogen and helium, including carbon, oxygen, iron and gold—through generations of exploding stars. The data also provide new information about the gas clouds orbiting Sagittarius A*, the supermassive black hole at the center of our galaxy, while a separate study finds that local conditions make it difficult to use this gas as a reliable record of the black hole’s past activity.
JWST measures the gas near Sagittarius A*
“We know that there is a black hole at the center of our galaxy (Sagittarius A*) that is drawing matter into itself, but we know that it is eating far less material and much more slowly than other supermassive black holes,” said McGill University student Nicole Ford, first author of a study published in Astronomy Magazine.
“To understand why this is happening, we need to examine the properties of the materials that can be consumed, such as gas, dust, and the stars we orbit.”
For the study, Ford and her colleagues analyzed data from NASA/ESA/CSA’s James Webb Space Telescope. JWST measures infrared light across a broad range of wavelengths with unprecedented spectral and spatial resolution.
These capabilities allowed the researchers to distinguish the thermal signatures of multiple gas clouds orbiting near Sagittarius A*. They could also measure the metallic composition of each cloud with greater accuracy.
The observations indicate that the metal enrichment in the galactic center likely reflects material produced by successive generations of exploding stars. Studying that composition can help researchers understand which materials are available to the black hole as it accretes matter.
Local conditions complicate the black hole’s history
In a separate study published in the Astrophysical Journal, McGill University astronomer Mayura Balakrishnan and her colleagues searched the gas for evidence of past energy bursts from black holes.
They found that local conditions influence the gas so strongly that isolating the black hole’s impact is difficult. This does not rule out the possibility that Sagittarius A* produced powerful outbursts in the past, but it means the gas cannot serve as a reliable record of the black hole’s history.
“To understand how black holes attract matter, we need to compare these observations with simulations of how gas evolves over longer timescales,” Ford said.
Research references
Nicole M. Ford et al. 2026. “Ionization structure and metal enrichment of the galactic center mini-spiral observed by JWST.” A.J. 172, 267. doi: 10.3847/1538-3881/ae994d
Mayura Balakrishnan et al. 2026. “Isolation of Sgr A East: The first uncontaminated X-ray map of the supernova remnant at the center of the galaxy.” APJ 1003, 128. doi: 10.3847/1538-4357/ae5dbe
Source: www.sci.news
