Over 13 billion years ago, the first galaxies in the Universe formed. They were elliptical, with intermediate black holes (IMBHs) at their centers surrounded by a halo of stars, gas, and dust. Over time, these galaxies evolved by flattening out into disks with a large bulge in the middle. They were then drawn together by mutual gravitational attraction to form galaxy clusters, massive collections that comprise the large-scale cosmic structure. This force of attraction also led to mergers, where galaxies and their central black holes came together to create larger spiral galaxies with central supermassive black holes (SMBHs).
This process of mergers and assimilation (and their role in galactic evolution) is still a mystery to astronomers today since much of it took place during the early Universe, which is still very difficult to observe with existing telescopes. Using data from NASA’s Chandra X-ray Observatory and the International Gemini Observatory, an international team of astronomers observed a lone distant galaxy that appears to have consumed all of its former companions. Their findings, which recently appeared in The Astrophysical Journal, suggest galaxies in the early Universe grew faster than previously thought.
Estimating stellar age has always been a challenge for astronomers. Now, a certain class of exoplanets is making the process even more complicated. Hot Jupiters – gas giants with orbital periods smaller than that of Mercury – appear to have an anti-aging effect on their stars, according to a new study. These enormous planets inflict both magnetic and tidal interference on their host star, speeding up the star’s rotation and causing them to emit X-rays more energetically, both of which are hallmarks of stellar youth. The result calls into question some of what we previously believed about stellar age, and offers a glimpse at the ongoing interconnectivity between a star and its planets long after their formation.
NASA scientist have released images combining the early data from the James Webb Space Telescope with X-ray data taken with the Chandra Observatory. Besides their beauty, the images offer insights into the inner workings of some of the most complex astrophysical phenomena in the universe.
Cassiopeia A is the remnant of a supernova that exploded 11,000 light-years away. The light from the exploding star likely reached Earth around 1670 (only a couple of years before Newton invented the reflecting telescope.) But there are no records of it because the optical light didn’t reach Earth.
The Cass A nebula ripples with energy and light from the ancient explosion and is one of the most-studied objects in deep space. It’s an expanding gas shell blasted into space when its progenitor star exploded.
But Cass A isn’t expanding evenly, and astronomers think they know why.
Why is there so much antimatter in the Universe? Ordinary matter is far more plentiful than antimatter, but scientists keep detecting more and more antimatter in the form of positrons. More positrons reach Earth than standard models predict. Where do they come from?
Scientists think pulsars are one source, and a new study strengthens that idea.
Not that long ago,, astronomers weren’t sure that exoplanets even existed. Now we know that there are thousands of them and that most stars probably harbour exoplanets. There could be hundreds of billions of exoplanets in the Milky Way, by some estimates. So there’s no reason to think that stars in other galaxies don’t host planets.
But to find one of those planets in another galaxy? That is a significant scientific achievement.
Planetary formation theory has been undergoing a lot of changes recently, with an ever expanding litany of events that can potentially impact it. Everything from gravity to magnetic fields seems to impact this complex process. Now scientists want to add another confounding factor – massive solar flares thousands of times more powerful than the most powerful we have ever observed from the Sun.
One of the best things about that universe is that there is so much to it. If you look hard enough, you can most likely find any combination of astronomical events happening. Not long ago we reported on research that found 7 separate instances of three galaxies colliding with one another. Now, a team led by Jonathan Williams of the University of Maryland has found another triple galaxy merging cluster, but this one might potentially have two active supermassive black holes, allowing astronomers to peer into the system dynamics of two of the universe’s most extreme objects running into one another.
The core of the Milky Way Galaxy (aka. Galactic Center), the region around which the rest of the galaxy revolves, is a strange and mysterious place. It is here that the Supermassive Black Hole (SMBH) that powers the compact radio source known as Sagittarius A* is located. It is also the most compact region in the galaxy, with an estimated 10 million stars within 3.26 light-years of the Galactic Center.
X-rays offer a unique insight into the astronomical world. Invisible to the naked eye, most commonly they are thought of as the semi-dangerous source of medical scans. However, X-ray observatories, like the Chandra X-ray Observatory are capable of seeing astronomical features that no other telescope can. Recently scientists found some of those X-rays coming from a relatively unexpected source – Uranus.