Back in the Chilean desert, the Atacama Cosmology Telescope’s successor—the Simons Observatory, which has been built on the same site—opened for business and took its first image. It will begin its even more detailed examination of the CMB in the coming months.
19.03.2025
The Atacama Cosmology Telescope captures the afterglow of the Big Bang in unprecedented detail
A detail of the new map of the cosmic microwave background radiation from the Atacama Cosmology Telescope showing how polarization reveals the movement of primordial gasACT COLLABORATION
A strange-looking telescope that scanned the skies from a perch in northern Chile for 15 years has released its final data set: detailed maps of the infant universe showing the roiling clouds of hydrogen and helium gas that would one day coalesce into the stars and galaxies we see today.
The Atacama Cosmology Telescope is not the first to survey the cosmic microwave background (CMB), the light released 380,000 years after the Big Bang when the early universe’s soup of particles formed atoms and space became transparent. But the data—posted as preprints online today—give researchers a new level of detail on the density of the gas clouds and how they were moving.
In the image above, different colors show areas where the polarization of the CMB light—its direction of vibration—differ, revealing how gases first move tangentially around areas of higher density (orange) and later fall straight in (blue) under the influence of gravity. “The thing that’s really advanced is the fine-scale features of the CMB and in polarization,” says Jo Dunkley, a cosmologist at Princeton University who led the analysis of the data. “That lets you check tests for unusual physics, particularly in the early universe, that might be going on.”
Using the data, Dunkley and colleagues tested how well the standard cosmological theory, known as lambda cold dark matter, described the universe at that time 13.8 billion years ago; it’s a remarkably good fit, they conclude.
Others are looking forward to using the data for their own analyses. “We’re very interested to see what they found,” says cosmologist Seshadri Nadathur of the University of Portsmouth, a member of the team for the Dark Energy Spectroscopic Instrument, which will also release new results this week.
Quelle: AAAS
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