Starship Asterisk*

Artist’s impression of galaxy ZF-COSMOS-20115. The galaxy has likely blown off all the gas that caused its rapid star formation and mass growth and rapidly turned into a compact red galaxy. (Credit: Leonard Doublet, Swinburne University)

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An international team of astronomers has, for the first time, spotted a massive, inactive galaxy from a time when the Universe was only 1.65 billion years old.

Astronomers expect most galaxies from this epoch to be low-mass minnows, busily forming stars. However, this galaxy is ‘a monster’ and inactive, according to Professor Karl Glazebrook, Director of Swinburne’s Centre for Astrophysics and Supercomputing, who led the team.

The researchers found that within a short time period this massive galaxy, known as ZF-COSMOS-20115, formed all its stars (three times more than our Milky Way today) through an extreme star-burst event. But it stopped forming stars only a billion years after the Big Bang to become a quiescent or ‘red and dead’ galaxy -- common in our universe today, but not expected to exist at this ancient epoch.

The galaxy is also small and extremely dense: it has 300 billion stars crammed into a region of space about the same size as the distance from the Sun to the nearby Orion Nebula. ...

• Nature 544(7648):71 (06 Apr 2017) DOI: 10.1038/nature21680
  arXiv.org > astro-ph > arXiv:1702.01751 > 06 Feb 2017 (v1), 29 Mar 2017 (v2)