Hubble Discovers Pair of Dwarf Galaxy Preparing for a Firestorm of Star Birth
NASA's Hubble Space Telescope has discovered a pair of tiny dwarf galaxies making their journey from the region of the Universe called Local Void into a nearby "big city" packed with galaxies, which may lead firestorm of star birth.
The galaxies, dubbed as Pisces A and B, are believed to have similar appearance to modern-day dwarf galaxies during earlier epoch. Pisces A is located about 19 million light-years away from Earth, while Pisces B is roughly 30 million light-years away. Each galaxy contains only about 10 million stars, with about 20 to 30 bright blue stars, suggesting that the galaxies are less than 100 million years old.
Most of the galaxies' life was spent in a region of the Universe that is sparsely populated with galaxies, which spans about 150 million light -years across. Due to this, their hydrogen content is somewhat higher relative to similar galaxies.
"These galaxies may have spent most of their history in the void," explained lead researcher Erik Tollerud of the Space Telescope Science Institute in Baltimore, Maryland, in a statement. "If this is true, the void environment would have slowed their evolution."
As Pisces A and B get pulled by the gravity of the galactic big city, astronomers expect a boom in star birth triggered by intergalactic gas raining down on them as they plow through the dense region.
According to a press release, the discovery of Pisces A and B were made using radio telescopes in a unique survey to measure the hydrogen content in our Milky Way. Out of the thousand small blobs of dense hydrogen gas observed, the astronomers chose 30 to 50 of those blobs that are most likely to be galaxies. Using the WIYN telescope in Arizona, researchers studied 15 of the potential galaxies in visible light. They then selected two of the most promising galaxy candidate and observed them using Hubble's Advanced Camera for Surveys, which in turn confirmed that Pisces A and B are dwarf galaxies.