dwarf galaxies tagged posts

This is a dwarf galaxy with a starburst. Credit: UC Riverside

Astronomers use computer simulations based on theoretical models to explain massive star formation observed in dwarf galaxies. One of the main predictions of the current model of the creation of structures in the universe, known at the Lambda Cold Dark Mattermodel, is that galaxies are embedded in very extended and massive halos of dark matter surrounded by many thousands of smaller sub-halos also made from dark matter.

Around large galaxies, eg Milky Way, these dark matter sub-halos are large enough to host enough gas and dust to form small galaxies on their own, and some of these galactic companions, known as satellite galaxies, can be observed...

Hubble Frontier Fields view of MACSJ0416.1–2403 Credit: NASA, ESA and the HST Frontier Fields team (STScI)

Observations have taken advantage of gravitational lensing to reveal the largest sample of the faintest and earliest known galaxies in the Universe. Some of these galaxies formed just 600 million years after the Big Bang and are fainter than any other galaxy yet uncovered by Hubble. The team has determined, for the 1st time that these small galaxies were vital to creating the Universe that we see today.

Hakim Atek’s team has discovered >250 tiny galaxies that existed only 600-900 million years after the Big Bang,one of the largest samples of dwarf galaxies yet to be discovered at these epochs...