NAOJ: Carbon Cocoons Surround Growing Galaxies

[bystander]

Carbon Cocoons Surround Growing Galaxies
ALMA | National Astronomical Observatory of Japan | 2019 Dec 16

ALMA Spots Earliest Environment Pollution in the Universe

ALMA and Hubble image of a young galaxy surrounded by a gaseous carbon cocoon. The red color shows the distribution of carbon gas imaged by combining the ALMA data for 18 galaxies. The stellar distribution photographed by Hubble is shown in blue. The image size is 3.8 arcsec x 3.8 arcsec, which corresponds 70,000 light years x 70,000 light years at the distance of 12.8 billion light years away. Credit: ALMA (ESO/NAOJ/NRAO), NASA/ESA/Hubble, Fujimoto et al.

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Researchers have discovered gigantic clouds of gaseous carbon spanning more than a radius of 30,000 light-years around young galaxies using the Atacama Large Millimeter/submillimeter Array (ALMA). This is the first confirmation that carbon atoms produced inside of stars in the early Universe have spread beyond galaxies. No theoretical studies have predicted such huge carbon cocoons around growing galaxies, which raises questions about our current understanding of cosmic evolution.

“We examined the ALMA Science Archive thoroughly and collected all the data that contain radio signals from carbon ions in galaxies in the early Universe, only one billion years after the Big Bang,” says Seiji Fujimoto ... “By combining all the data, we achieved unprecedented sensitivity. To obtain a dataset of the same quality with one observation would take 20 times longer than typical ALMA observations, which is almost impossible to achieve.”

Heavy elements such as carbon and oxygen did not exist in the Universe at the time of the Big Bang. They were formed later by nuclear fusion in stars. However, it is not yet understood how these elements spread throughout the Universe. Astronomers have found heavy elements inside baby galaxies but not beyond those galaxies, due to the limited sensitivity of their telescopes. This research team summed the faint signals stored in the data archive and pushed the limits.

“The gaseous carbon clouds are almost five times larger than the distribution of stars in the galaxies, as observed with the Hubble Space Telescope,” explains Masami Ouchi ... “We spotted diffuse but huge clouds floating in the coal-black Universe.” ...

First Identification of 10 kpc [CII] 158 μm Halos around Star-forming Galaxies at z = 5–7 ~ Seiji Fujimoto et al

• Astrophysical Journal 887(2):107 (20 Dec 2019) DOI: 10.3847/1538-4357/ab480f
• arXiv.org > astro-ph > arXiv:1902.06760 > 18 Feb 2019 (v1), 28 Sep 2019 (v4)