star formation

Amazing high resolution image of the core of the milky way, a region with surprisingly low star formation compared to other galaxies

Amazing high resolution image of the core of the milky way, a region with surprisingly low star formation compared to other galaxies

Compared to some other galaxies in our Universe, the Milky Way is a rather subtle character. In fact, there are galaxies that are a thousands times as luminous as the Milky Way, owing to the presence of warm gas in the galaxy’s Central Molecular Zone (CMZ). This gas is heated by massive bursts of star formation that surround the Supermassive Black Hole (SMBH) at the nucleus of the galaxy.

Supermassive black holes can turn star formation on and off in a large galaxy

Supermassive black holes can turn star formation on and off in a large galaxy

In the 1970s, astronomers discovered that a particularly large black hole (Sagittarius A*) existed at the center of our galaxy. In time, they came to understand that similar Supermassive Black Holes (SMBHs) existed in the center of most massive galaxies. The presence of these black holes was also what differentiated galaxies that had particularly luminous cores – aka. Active Galactic Nuclei (AGN) – from those that didn’t.

Self-made stars - Astronomers observe black hole producing cold, star-making fuel from hot plasma jets and bubbles

Self-made stars - Astronomers observe black hole producing cold, star-making fuel from hot plasma jets and bubbles

The Phoenix cluster is an enormous accumulation of about 1,000 galaxies, located 5.7 billion light years from Earth. At its center lies a massive galaxy, which appears to be spitting out stars at a rate of about 1,000 per year. Most other galaxies in the universe are far less productive, squeaking out just a few stars each year, and scientists have wondered what has fueled the Phoenix cluster’s extreme stellar output.

Is our Milky Way galaxy a zombie, already dead and we don’t know it?

Is our Milky Way galaxy a zombie, already dead and we don’t know it?

Like a zombie, the Milky Way galaxy may already be dead but it still keeps going. Our galactic neighbor Andromeda almost certainly expired a few billion years ago, but only recently started showing outward signs of its demise.

Why do some galaxies stop making new stars?

Why do some galaxies stop making new stars?

Our own galaxy, the Milky Way, is dotted with fascinating star-forming regions. Some galaxies can produce hundreds of new stars in a single year, and individual galaxies can contain many billions of stars. But why is it that some galaxies stop making new stars?