National Astronomical Observatory of Japan

Unstoppable Monster in the Early Universe - ALMA obtains most detailed view of distant starburst galaxy

| Science

Astronomers obtained the most detailed anatomy chart of a monster galaxy located 12.4 billion light-years away. Using the Atacama Large Millimeter/submillimeter Array (ALMA), the team revealed that the molecular clouds in the galaxy are highly unstable, which leads to runaway star formation. Monster galaxies are thought to be the ancestors of the huge elliptical galaxies in today’s Universe, therefore these findings pave the way to understand the formation and evolution of such galaxies.

“One of the best parts of ALMA observations is to see the far-away galaxies with unprecedented resolution,” says Ken-ichi Tadaki, a postdoctoral researcher at the Japan Society for the Promotion of Science and the National Astronomical Observatory of Japan, the lead author of the research paper published in the journal Nature.

onster galaxies form stars at a startling pace; 1000 times higher than the star formation in our Galaxy.
Monster galaxy COSMOS-AzTEC-1 observed with ALMA. ALMA revealed the distribution of molecular gas (left) and dust particles (right). In addition to the dense cloud in the center, the research team found two dense clouds several thousand light-years away from the center. These dense clouds are dynamically unstable and thought to be the sites of intense star formation. (Credit: ALMA (ESO/NAOJ/NRAO), Tadaki et al.) Original size (1.2MB)

Monster galaxies form stars at a startling pace; 1000 times higher than the star formation in our Galaxy. But why are they so active? To tackle this problem, Tadaki and the team utilized the high resolution and high sensitivity of ALMA to observe a monster galaxy COSMOS-AzTEC-1 and obtain a detailed map of the distribution and the motion of the gas. Thanks to the most extended ALMA antenna configuration of 16 km, this is the highest resolution molecular gas map of a distant monster galaxy ever made.

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