National Radio Astronomy Observatory | 2018 Jan 10
Earliest Galaxies in the Universe’s History Spun Like the Milky Way
Atacama Large Millimeter/submillimeter Array | 2018 Jan 10
Astronomers have looked back to a time soon after the Big Bang, and have discovered swirling gas in some of the earliest galaxies to have formed in the Universe. These ‘newborns’ – observed as they appeared nearly 13 billion years ago – spun like a whirlpool, similar to our own Milky Way.
An international team led by Renske Smit from the Kavli Institute of Cosmology at the University of Cambridge used the Atacama Large Millimeter/submillimeter Array (ALMA) to open a new window onto the distant Universe, and have identified normal star-forming galaxies at a very early stage in cosmic history. The results are reported in the journal Nature, and will be presented at the 231st meeting of the American Astronomical Society.
Light from distant objects takes time to reach Earth, so observing objects that are billions of light years away enables us to look back in time and directly observe the formation of the earliest galaxies. The Universe at that time, however, was filled with an obscuring “haze” of neutral hydrogen gas, which makes it difficult to see the formation of the very first galaxies with optical telescopes.
Smit and her colleagues used ALMA to observe two small newborn galaxies, as they existed just 800 million years after the Big Bang. By analyzing the spectral ‘fingerprint’ of the far-infrared light collected by ALMA, they were able to establish the distance to the galaxies and, for the first time, see the internal motion of the gas that fueled their growth. ...
Rotation in [C II]-emitting gas in two galaxies at a redshift of 6.8 - Renske Smit et al
- Nature 553(7687):178 (10 Jan 2018) DOI: 10.1038/nature24631