adplus-dvertising
Connect with us

Science

Astronomers find the Wolfe Disk, a galaxy that shouldn't exist, in the distant universe – MSN Money

Published

 on


Astronomers have spotted a massive disk galaxy, not unlike our own, that formed 12.5 billion years ago when our 13.8 billion-year-old universe was only a tenth of its current age. But according to what scientists know about galaxy formation, this one has no business being in the distant universe.






© NRAO/AUI/NSF, S. Dagnello
Artist impression of the Wolfe Disk, a massive rotating disk galaxy in the early, dusty universe. The galaxy was initially discovered when ALMA examined the light from a more distant quasar (top left). Credit: NRAO/AUI/NSF, S. Dagnello

This discovery is challenging how astronomers think about galaxy formation in the early universe.

300x250x1
Loading...

Load Error

It’s known as Galaxy DLA0817g, but astronomers nicknamed it the Wolfe Disk after late astronomer Arthur M. Wolfe, former doctoral advisor to three of the study’s four authors. It represents the most distant rotating disk galaxy they have ever observed, thanks to the Atacama Large Millimeter/submillimeter Array of telescopes in Chile known as ALMA.

According to their observations, the galaxy’s disk has a mass of 70 billion times that of our sun. It’s also rotating at 170 miles per second, which is similar to our Milky Way galaxy. But galaxies with stable, well-formed disks, like the Milky Way, formed gradually and appeared later in the universe’s timeline, with some dated to 6 billion years after the Big Bang.

In the early days after the Big Bang, the universe was largely a blank slate. Eventually, this was followed by galaxy formation that was pretty messy. Small galaxies merged and crashed together along with hot gas clumps.

“Most galaxies that we find early in the universe look like train wrecks because they underwent consistent and often ‘violent’ merging,” said Marcel Neeleman, lead study author and postdoctoral researcher at the Max Planck Institute for Astronomy in Heidelberg, Germany, in a statement. “These hot mergers make it difficult to form well-ordered, cold rotating disks like we observe in our present universe.”

The study published this week in the journal Nature.

So how did a well-formed rotating disk galaxy appear during this turbulent period? This galaxy formed and grew, researchers concluded, in a different way, known as cold-mode accretion.

Much of what astronomers know about galaxy formation is based on hierarchy. In the beginning, halo-like structures of dark matter, a large, unseen component of the universe known by its effect on surrounding matter, drew in gas. Mergers created something larger where star formation was possible, and eventually, a galaxy was born.

The gas drawn in by the dark matter halos was heated by the collisions, and it would form a disk once it cooled — which could take place over billions of years.

Cold brew

But in the cold scenario, much cooler gas is drawn into a new galaxy and allows for quicker formation of a disk.

“We think the Wolfe Disk has grown primarily through the steady accretion of cold gas,” said J. Xavier Prochaska, study coauthor and professor of astronomy and astrophysics of the University of California, Santa Cruz, in a statement. “Still, one of the questions that remains is how to assemble such a large gas mass while maintaining a relatively stable, rotating disk.”

The researchers also used data from the Hubble Space Telescope and the National Science Foundation’s Karl G. Jansky Very Large Array of radio antennae in New Mexico to understand what kind of star formation was occurring in the galaxy.

“The star formation rate in the Wolfe Disk is at least 10 times higher than in our own galaxy,” explained Prochaska. “It must be one of the most productive disk galaxies in the early universe.”



a blurry image of a flower: This ALMA image shows the Wolfe Disk in the distant universe.


© NRAO/AUI/NSF
This ALMA image shows the Wolfe Disk in the distant universe.

Neeleman and his colleagues first spotted the Wolfe Disk using ALMA in 2017 when light from a quasar passed through hydrogen gas around the galaxy and revealed it. A quasar, which looks a bit like a star through a telescope, is actually a remote object that emits a large amount of energy likely powered by matter falling on a black hole at the center of a galaxy. The light helped them identify this normal galaxy, rather than the direct light emitted by extremely bright galaxies.

Otherwise, distant galaxies are hard to observe because they’re so faint. But this “absorption” of light method using quasars can happen when the telescopes, galaxy and quasar are in alignment, which is rare — unless galaxies like this were more common in the early universe.

“The fact that we found the Wolfe Disk using this method, tells us that it belongs to the normal population of galaxies present at early times,” Neeleman said. “When our newest observations with ALMA surprisingly showed that it is rotating, we realized that early rotating disk galaxies are not as rare as we thought and that there should be a lot more of them out there. Thanks to ALMA, we now have unambiguous evidence that they occur as early as 1.5 billion years after the Big Bang.”

Future research and observation is needed to understand how common this cold method of galaxy formation was in the early universe.

Let’s block ads! (Why?)

728x90x4

Source link

Continue Reading

Science

SpaceX launch marks 300th successful booster landing – Phys.org

Published

 on


Credit: Unsplash/CC0 Public Domain

SpaceX sent up the 30th launch from the Space Coast for the year on the evening of April 23, a mission that also featured the company’s 300th successful booster recovery.

A Falcon 9 rocket carrying 23 of SpaceX’s Starlink internet satellites blasted off at 6:17 p.m. Eastern time from Cape Canaveral Space Force Station’s Space Launch Complex 40.

300x250x1

The first-stage booster set a milestone of the 300th time a Falcon 9 or Falcon Heavy booster made a successful recovery landing, and the 270th time SpaceX has reflown a booster.

This particular booster made its ninth trip to space, a resume that includes one human spaceflight, Crew-6. It made its latest recovery landing downrange on the droneship Just Read the Instructions in the Atlantic Ocean.

The company’s first successful booster recovery came in December 2015, and it has not had a failed booster landing since February 2021.

The current record holder for flights flew 11 days ago making its 20th trip off the .

SpaceX has been responsible for all but two of the launches this year from either Kennedy Space Center or Cape Canaveral with United Launch Alliance having launched the other two.

SpaceX could knock out more launches before the end of the month, putting the Space Coast on pace to hit more than 90 by the end of the year, but the rate of launches by SpaceX is also set to pick up for the remainder of the year with some turnaround times at the Cape’s SLC-40 coming in less than three days.

That could amp up frequency so the Space Coast could surpass 100 launches before the end of the year, with the majority coming from SpaceX. It hosted 72 launches in 2023.

More launches from ULA are on tap as well, though, including the May 6 launch atop an Atlas V rocket of the Boeing CST-100 Starliner with a pair of NASA astronauts to the International Space Station.

ULA is also preparing for the second launch ever of its new Vulcan Centaur rocket, which recently received its second Blue Origin BE-4 engine and is just waiting on the payload, Sierra Space’s Dream Chaser spacecraft, to make its way to the Space Coast.

Blue Origin has its own it wants to launch this year as well, with New Glenn making its debut as early as September, according to SLD 45’s range manifest.

2024 Orlando Sentinel. Distributed by Tribune Content Agency, LLC.

Citation:
SpaceX launch marks 300th successful booster landing (2024, April 24)
retrieved 24 April 2024
from https://phys.org/news/2024-04-spacex-300th-successful-booster.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

Adblock test (Why?)

728x90x4

Source link

Continue Reading

Science

Wildlife Wednesday: loons are suffering as water clarity diminishes – Canadian Geographic

Published

 on


The common loon, that icon of northern wilderness, is under threat from climate change due to declining water clarity. Published earlier this month in the journal Ecology, a study conducted by biologists from Chapman University and Rensselaer Polytechnic Institute in the U.S. has demonstrated the first clear evidence of an effect of climate change on this species whose distinct call is so tied to the soundscape of Canada’s lakes and wetlands.

Through the course of their research, the scientists found that July rainfall results in reduced July water clarify in loon territories in Northern Wisconsin. In turn, this makes it difficult for adult loons to find and capture their prey — mainly small fish — underwater, meaning they are unable to meet their chicks’ metabolic needs. Undernourished, the chicks face higher mortality rates. The consistent foraging techniques used by loons across their range means this impact is likely echoed wherever they are found — from Alaska to Canada to Iceland.

The researchers used Landsat imagery to find that there has been a 25-year consistent decline in water clarity, and during this period, body weights of adult loon and chicks alike have also declined. With July being the month of most rapid growth in young loons, the study also pinpointed water clarity in July as being the greatest predictor of loon body weight. 

300x250x1

One explanation for why heavier rainfall leads to reduced water clarity is the rain might carry dissolved organic matter into lakes from adjacent streams and shoreline areas. Lawn fertilizers, pet waste and septic system leaks may also be to blame.

The researchers, led by Chapman University professor Walter Piper, hope to use these insights to further conservation efforts for this bird Piper describes as both “so beloved and so poorly understood.”

Return of the king

Adblock test (Why?)

728x90x4

Source link

Continue Reading

Science

Giant prehistoric salmon had tusk-like teeth for defence, building nests

Published

 on

The artwork and publicity materials showcasing a giant salmon that lived five million years ago were ready to go to promote a new exhibit, when the discovery of two fossilized skulls immediately changed what researchers knew about the fish.

Initial fossil discoveries of the 2.7-metre-long salmon in Oregon in the 1970s were incomplete and had led researchers to mistakenly suggest the fish had fang-like teeth.

It was dubbed the “sabre-toothed salmon” and became a kind of mascot for the Museum of Natural and Cultural History at the University of Oregon, says researcher Edward Davis.

But then came discovery of two skulls in 2014.

300x250x1

Davis, a member of the team that found the skulls, says it wasn’t until they got back to the lab that he realized the significance of the discovery that has led to the renaming of the fish in a new, peer-reviewed study.

“There were these two skulls staring at me with sideways teeth,” says Davis, an associate professor in the department of earth sciences at the university.

In that position, the tusk-like teeth could not have been used for biting, he says.

“That was definitely a surprising moment,” says Davis, who serves as director of the Condon Fossil Collection at the university’s Museum of Natural and Cultural History.

“I realized that all of the artwork and all of the publicity materials and bumper stickers and buttons and T-shirts we had just made two months prior, for the new exhibit, were all out of date,” he says with a laugh.

Davis is co-author of the new study in the journal PLOS One, which renames the giant fish the “spike-toothed salmon.”

It says the salmon used the tusk-like spikes for building nests to spawn, and as defence mechanisms against predators and other salmon.

The salmon lived about five million years ago at a time when Earth was transitioning from warmer to relatively cooler conditions, Davis says.

It’s hard to know exactly why the relatives of today’s sockeye went extinct, but Davis says the cooler conditions would have affected the productivity of the Pacific Ocean and the amount of rain feeding rivers that served as their spawning areas.

Another co-author, Brian Sidlauskas, says a fish the size of the spike-toothed salmon must have been targeted by predators such as killer whales or sharks.

“I like to think … it’s almost like a sledgehammer, these salmon swinging their head back and forth in order to fend off things that might want to feast on them,” he says.

Sidlauskas says analysis by the lead author of the paper, Kerin Claeson, found both male and female salmon had the “multi-functional” spike-tooth feature.

“That’s part of our reason for hypothesizing that this tooth is multi-functional … It could easily be for digging out nests,” he says.

“Think about how big the (nest) would have to be for an animal of this size, and then carving it out in what’s probably pretty shallow water; and so having an extra digging tool attached to your head could be really useful.”

Sidlauskas says the giant salmon help researchers understand the boundaries of what’s possible with the evolution of salmon, but they also capture the human imagination and a sense of wonder about what’s possible on Earth.

“I think it helps us value a little more what we do still have, or I hope that it does. That animal is no longer with us, but it is a product of the same biosphere that sustains us.”

This report by The Canadian Press was first published April 24, 2024.

Brenna Owen, The Canadian Press

Adblock test (Why?)

728x90x4

Source link

Continue Reading

Trending