We’ve known for a while about the large-scale structure of the Universe. Galaxies reside in filaments hundreds of millions of light-years long, on a backbone of dark matter. And, where those filaments meet, there are galaxy clusters. Between them are massive voids, where galaxies are sparse. Now a team of astronomers in Germany and their colleagues in China and Estonia have made an intriguing discovery.
These massive filaments are rotating, and this kind of rotation on such a massive scale has never been seen before.
A galaxy’s main business is star formation. And when they’re young, like youth everywhere, they keep themselves busy with it. But galaxies age, evolve, and experience a slow-down in their rate of star formation. Eventually, galaxies cease forming new stars altogether, and astronomers call that quenching. They’ve been studying quenching for decades, yet much about it remains a mystery.
A new study based on the IllustrisTNG simulations has found a link between a galaxy’s quenching and its stellar size.
Galaxy mergers are beautiful sights, but ultimately deadly. In the midst of the collision, the combined galaxy will shine brighter than it ever has before. But that glory comes with a price: all those new stars use up all the available fuel, and star formation grinds to a halt.
Computers are known for their ability to spot patterns. It’s what they are good at, and over the last 50+ years they have continued to improve. But they only know how to spot patterns if they know where to look for them in data. So sometimes, it falls to a human to truly see a pattern that no one expected to be there.
That is exactly what happened in the case of the discovery of the most consistent active galaxy yet discovered. Anna Payne, a graduate student at the University of Hawai’i at Manoa, was looking into data collected by the All Sky Automated Survey for Supernovae (ASAS-SN), and notice a strange feature about one of its galaxies, known as ESO 253-3: it was getting significantly brighter every 114 days.
10 billion years ago, galaxies of the Universe were ablaze with the light of newly forming stars. This epic phase of history is known as “Cosmic Noon” – the height of all star creation. Galaxies like our Milky Way aren’t creating stars at nearly the rates they were in the ancient past. However, there is a time when galaxies in the present can explode with star formation – when they collide with each other. This recently published collage of merging galaxies by the Hubble HiPEEC survey (Hubble imaging Probe of Extreme Environments and Clusters) highlights six of these collisions which help us understand star formation in the early Universe.
Say hello to NGC 6946, otherwise known as the Fireworks Galaxy. This little galaxy is the most prolific producer of supernovae in the known universe, popping off those incredible explosions roughly once a decade. It’s secret? An incredibly high rate of star formation.
The galaxy NGC 1052-DF4 surprised scientists by having almost no dark matter to complement its stellar population. Recently a team of astronomers has provided an explanation: a nearby galaxy has stripped NGC 1052-DF4 of its dark matter, and is currently in the process of destroying the rest of it too.
Galaxies build themselves up slowly over time by cannibalizing their neighbors. Using an advanced suite of computer simulations, researchers have now traced back the evolutionary history of our own Milky Way.
In July of 2015, NASA’s New Horizons probe made history when it became the first mission ever to conduct a close flyby of Pluto. This was followed by the spacecraft making the first-ever encounter with a Kuiper Belt Object (KBO) – known as Arrokoth (aka. 2014 MU69) – on Dec.31st, 2018. In addition, its unique position in the outer Solar System has allowed astronomers to conduct rare and lucrative science operations.
The behaviour of galaxies in the early Universe attracts a lot of attention from researchers. In fact, everything about the early Universe is under intense scientific scrutiny for obvious reasons. But unlike the Universe’s first stars, which have all died long ago, the galaxies we see around us—including our own—have been here since the early days.
Current scientific thinking says that in the early days of the Universe, the galaxies grew slowly, taking billions of years to become what they are now. But new observations show that might not be the case.