Space and astronomy news
Ask most people what a galaxy is made up of, and they’ll say it’s made of stars. Our own galaxy, the Milky Way, hosts between about 100 to 300 billion stars, and we can see thousands of them with our unaided eyes. But most of a galaxy’s mass is actually gas, and the extent of the gas has been difficult to measure.
Researchers have found a way to see how far that gas extends into the cosmos.
Continue reading “The True Size of Galaxies is Much Larger Than We Thought”
Understanding the star formation rate (SFR) in a galaxy is critical to understanding the galaxy itself. Some galaxies are starburst galaxies with extremely high SFRs, some are quenched or quiescent galaxies with very low SFRs, and some are in the middle. Researchers used the JWST to observe a pair of galaxies at Cosmic Noon that are just beginning to merge to see how SFRs vary in different regions of both galaxies.
Continue reading “JWST Reveals Star Formation at Cosmic Noon”
In the contemporary Universe, massive galaxies are plentiful. But the Universe wasn’t always like this. Astronomers think that galaxies grew large through mergers, so what we see in space is the result of billions of years of galaxies merging. When galaxies merge, the merger can feed large quantities of gas into their centers, sometimes creating a quasar.
Much of this is theoretical and shrouded in mystery, but astronomers might have found evidence of a galaxy merger creating a quasar.
Continue reading “This Ancient Galaxy Merger Will Produce a very Luminous Quasar”
Scientists discovered the Andromeda galaxy, known as M31, hundreds of years ago, and around a century ago, we realized that it had negative radial velocity toward the Milky Way. In other words, eventually, the two galaxies would merge spectacularly. That has been common knowledge for astronomers since then, but is it really true? A new paper from researchers at the University of Helsinki looks at several confounding factors, including the gravitational influence of other galaxies in our local group, and finds only a 50% chance that the Milky Way will merge with the Andromeda galaxy in the next 10 billion years.
Continue reading “Are Andromeda and the Milky Way Doomed to Collide? Maybe Not”
Supermassive Black Holes (SMBHs) are located in the centers of large galaxies like ours. When they’re actively feeding, they produce more light and are called active galactic nuclei (AGN). But their details are difficult to observe clearly because large clouds of gas block our view.
The JWST was built just for circumstances like these.
Continue reading “The JWST Reveals the Nature of Dust Around an Active Galactic Nuclei”
Some galaxies experience rapid star formation hundreds or even thousands of times greater than the Milky Way. Astronomers think that mergers are behind these special galaxies, which were more abundant in the earlier Universe. But new results suggest no mergers are needed.
Continue reading “No Merger Needed: A Rotating Ring of Gas Creates A Hyperluminous Galaxy”
Look at most spiral or barred spiral galaxies and you will see multiple regions where stars are forming. These star forming regions are comprised of mostly hydrogen gas with a few other elements for good measure. The first galaxies in the Universe had huge supplies of this star forming gas. Left unchecked they could have burned through the gas quickly, generating enormous amounts of star formation. Life fast though and die young for such an energetic burst of star formation would soon fizzle out leaving behind dead and dying stars. In some way it seems, galaxies seem to regulate their star formation thanks to supermassive black holes at their centre.
Continue reading “Galaxies Regulate their Own Growth so they Don’t Run Out of Star Forming Gas”
How can young galaxies in the early Universe have ancient stars? That’s the question a team of astronomers set out to answer using JWST as a probe. They first spotted the massive objects in 2022 and are still working to explain what these things are.
Continue reading “Galaxies Filled With Old Stars Seen Shortly After the Big Bang”
First looks would tell most observers that supermassive black holes (SMBHs) and very young stars have nothing in common. But that’s not true. Astronomers have detected a supermassive black hole (SMBH) whose growth is regulated the same way a baby star’s is: by magnetic winds.
Continue reading “Growing Black Holes Have Much in Common With Baby Stars”
This is probably what the demise of the Hubble Space Telescope was always going to look like: components failing one by one, with no way to replace them. In the last few months, the Hubble has repeatedly gone into safe mode as one of its remaining three gyros keeps giving faulty readings. But the Hubble and the people operating it are resilient and resourceful. The telescope is back to science operations now, though in single gyro mode.
NASA has released the first image the Hubble captured in this mode, and it’s clear that the Hubble is performing well.
Continue reading “Here’s Hubble’s First Image in its New Pointing Mode”