The life cycle of molecular gas in the barred spiral galaxy Messier 83 appears to be driven mainly by the galaxy’s large-scale structure and rotation, rather than by feedback from newborn stars, according to a new study.

Astronomers have discovered that the Milky Way's spiral arms may extend farther and wider than previously thought, using data from NASA's Chandra X-ray Observatory and the European Space Agency's XMM-Newton. By analyzing X-ray light scattered by dust in the galaxy's arms from distant gamma-ray bursts, researchers measured the arms' distances and found the Outer and Outer-Scutum-Centaurus arms to be about 10% farther than earlier estimates. The study also determined the thickness of the most distant arm to be approximately 3,500 light-years. These findings could impact understanding of the galaxy's mass distribution, rotation, and overall structure. The research, published in Astronomy & Astrophysics, highlights the challenges of measuring galactic distances due to the rarity of observable gamma-ray bursts. While the revisions are small, they emphasize the importance of precise measurements for accurate cosmic models. The study underscores the evolving nature of astronomical knowledge and its potential implications for broader galactic evolution theories.