Last week I was super excited that we just might be on a solid path toward the discovery of Dark Energy in the physics of black holes. Since going down a rabbit hole of papers and papers referenced by those papers, I’ve had it pointed out that just like Modified Newtonian Gravity makes perfect sense with a nicely curated data set but doesn’t appear to actually be real, the Dark Energy from black holes research looks a lot less certain under critique.
So I got really excited and learned a few things, and hopefully you learned a few things, and those things may not be real, but they pointed out accurately that the Hubble tension can be fixed if something rebalances the equations of our universe at some point between the formation of the cosmic microwave background and the supernovae we observe in the modern universe. And until we figure out what that something might be, we’re going to see a lot of papers trying to use just about anything and everything that pops into the universe as a possible thing to blame. From now on, I’ll be more skeptical of the papers I read. I do still cheer on the black hole researchers. Their current formulation doesn’t fully get there, but maybe…
JWST is looking for answers
Until the truth is found, we will all have things we want to believe.
What we do know is something is missing from our current understanding of the universe, and the hardest for me to ignore evidence of this wrongness is the presence of massive galaxies and clusters of galaxies in the first billion years of our universe. These systems are found over and over in JWST images.
As Stacy McGraugh and collaborators point out in a new paper in the Astrophysical Journal, “Galaxies in the early Universe appear to have grown too big too fast, assembling into massive, monolithic objects more rapidly than anticipated.”
There is no single leading theory for how these galaxies formed so fast, but on the road to that understanding, we are finding a lot of cool stuff.
The Firefly Sparkle Galaxy
Consider the Firefly Sparkle Galaxy, a system that will forever make me think of My Little Pony. The light from this distant galaxy shines from when the universe was about 600 million years old. It is seen as a gravitationally lensed smear dotted with Sparkles on the outskirts of the MACS J1423 galaxy cluster.
We are able to see this distant system because the gravity from this cluster acts like an imperfect lens, and is able to collect and magnify light, while also distorting it.
Researchers can reverse this distortion to a certain degree, and when they model what this galaxy most likely looks like, it appears to be a teardrop-shaped cloud with 10 bright clusters of star formation. Near it are two other, smaller systems, that are 42,000 ly and 6,500 ly area. It is entirely possible that these systems will merge and over time to form a larger and larger system… possibly a system that looks a lot like our own Milky Way. As Yoshihisa Asada explains, “It has long been predicted that galaxies in the early Universe form through successive interactions and mergers with other tinier galaxies. We might be witnessing this process in action.”
This work appears in Nature and is led by Lamiya Mowla.
Spiderweb protocluster catches eyes
As we look at nearer objects, we continue to be dazzled by JWST’s discoveries and what they mean for cosmology.
Recent observations of the Spiderweb Protocluser used the JWST to peer through dust at the galaxies forming in this young system. The light has been travelling toward us for over 10 billion years and comes from a time when our universe was much less structured.
According to Jose M. Pérez-Martínez, “We are observing the build-up of one the largest structures in the Universe, a city of galaxies in construction. We know that most galaxies in local galaxy clusters (the biggest metropolises of the Universe) are old and not very active, whereas in this work we are looking at these objects during their adolescence. As this city in construction grows, their physical properties will also be affected. Now, Webb is giving us new insights into the build-up of such structures for the first time.”
Perez, along with Rhythm Shimakawa, was first author of one of the two papers published in the Astrophysical Journal about this research.
Star formation in this early cluster is driven by entirely different factors than are at play in our current universe. Today, clusters are filled with gas and dust that have been stripped out of the cluster’s galaxies as they interact, and as galaxies fly past each other. When galaxies plunge into clusters, rapid star formation will get triggered as they interact with that dust and other cluster galaxies. And when that star formation is over, the systems are left devoid of the material needed to feed future star formation.
In this system, star formation is fed by gas accumulating in galaxies and feeding the kinds of star formation we see in our galaxy.
This is a new stage in galaxy cluster evolution that wasn’t part of the story we’ve been telling for the past 20 years. We are seeing a kinder and gender period of structure formation, and I have to admit that after a lifetime of reading about galaxy harassment, ram pressure stripping, and other violent galaxy interactions, I find this paper truly delightful for both its science and lack of carnage.
Also remarkable is how little observing time was needed for this study. Using JWST’s massive mirror, they were able to get needed data in just 3.5 hours of observing time.
All these discoveries remind me of the line from Alice in Wonderland, where the White Queen says, “Why, sometimes I believed as many as six impossible things before breakfast.” Our universe is presenting us with what we once thought was impossible. This is an amazing time to be an astronomer.