Astronomers study the earliest Milky Way type galaxy ever seen | S27E04

[00:00:00] This is SpaceTime Series 27 Episode 4 for broadcast on the 8th of January 2024. Coming up on SpaceTime, Astronomers study the earliest Milky Way type galaxy ever seen, a new study on what makes up the center of a neutron star, and the final countdowns now underway

[00:00:20] to launch the first Vulcan central rocket. All that and more coming up on SpaceTime. Welcome to SpaceTime with Stuart Gary A new snapshot of an ancient far-off galaxy could help scientists better understand the origins of

[00:00:53] our own galaxy, the Milky Way. A report in the monthly notices of the Royal Astronomical Society has provided a detailed analysis of a galaxy known as BRI 1335-0417. It's the oldest and most distant spiral galaxy ever seen, located more than 12.4 billion light-years away in the

[00:01:16] constellation Virgo. The new observations using ALMA, the Atacama Millimeter Submillimeter Array Radio Telescope in Chile, have allowed the authors to undertake a closer look at this ancient galaxy in far greater detail. The study's lead author, Dr Takafumi Sikui from the Australian

[00:01:33] National University, says he was especially interested in how gas was moving into and throughout the galaxy. Gas is a key ingredient for forming new stars, and so it gives astronomers important clues about how a galaxy is fueling its star formation. In this case, the authors were not

[00:01:51] only able to capture the motion of gas around BRI 1335-0417 but also reveal the formation of a seismic wave, a first in this type of early galaxy. Sikui says the galaxy's disk, a flat mass of

[00:02:07] rotating stars, gas and dust, moves in a way not dissimilar to ripples spreading out in a pond after a rock's been thrown in it. The vertically oscillating motion of the disk is due to an external source,

[00:02:19] often either new gas streaming into the galaxy or by coming into contact with other smaller galaxies. Both possibilities would bombard the galaxy with new fuel for star formation. The study also revealed a bar-like structure in the disk. Galactic bars can disrupt gas,

[00:02:36] transporting it towards the galaxy's center. The bar discovered in BRI 1335-0417 is the most distant known structure of this kind. Together these results are showing the dynamic growth of a young galaxy. Because BRI 1335-0417 is so far away, it takes its light a long time to reach the

[00:02:59] Earth. The images of the galaxy seen through telescopes in the present day are actually a throwback to the galaxy's early days when the universe was just 10% of its current age. Interestingly, early galaxies have been found to form stars at a much faster rate than modern

[00:03:15] galaxies. Our Milky Way, for example, only produces one solar mass worth of stars every Earth year. And this is also true for BRI 1335-0417, which despite having a similar mass to our Milky Way galaxy, forms new stars at a rate hundreds of times faster. So the authors wanted

[00:03:35] to find out exactly how gas is supplied to keep up with this rapid rate of star formation. But spiral structures are rare in the early universe, and exactly how they form also remains unknown. But the study is providing some crucial information which will allow scientists to try

[00:03:52] and develop new hypotheses to try and find the most likely scenarios. Tsukui says while it's impossible to observe the galaxy's evolution directly, these observations provide a snapshot, allowing computer simulations to help piece the story together.

[00:04:10] It's special because it forms a star at an exceptionally high rate, a few hundred times faster than our Milky Way galaxy. And we are very curious what makes the galaxy form stars at an

[00:04:25] initial rate and how the gas ingredient of stars is flowed into the galaxy. So that's why we looked at the gas motions in the galaxy, how gas is supplied and why star forms at this very high rate.

[00:04:40] When one looks back 12 billion years to such an early time in the history of the universe, you're right at the height of this Deliverance Epoch when a lot of star formation was going on. Is that because the universe was a smaller place and things were closer together?

[00:04:57] Yeah, the universe was small so I think the gas is more denser. But I think more violent gas is supplied to the galaxy at higher rate and probably that makes the galaxy more active, forming stars.

[00:05:13] Would it have been easier to form molecular gas which is needed for star formation in that sort of an environment? Yeah, yeah, exactly, exactly. We think that for star formation to happen, some sort of compression of gas, additional compression of gas

[00:05:28] may be required. And what we observed, the seismic ripple propagating the disk, maybe I can't explain data, may be important for forming stars in this galaxy just like the Maypole dance where people

[00:05:41] dance around the pole and not just revolving but also going in and going out and forming, making the compression in the local region. So maybe the same thing happens in the disk,

[00:05:52] some region compressed by this wave for the stars to form. What we see, what we obtained is the gas velocity field in the line of sight. So we see the spiral arm in this galaxy but how exactly they

[00:06:09] form, how the spiral arm is exactly formed is still a mystery. We are not 100% sure but for this galaxy we think perturbations like gas actively falling into the disk and smaller galaxy

[00:06:25] coming into contact with the disk and then the disk is parted out and the density waves formed creating the spiral-like pattern in this galaxy. Is that what's responsible for the seismic wave

[00:06:38] forming that you saw? Yeah, yeah. As you know the materials tend to revolve around the center of galaxies and since we can measure the velocity of the gas at different regions of the galaxy, we subtract this large-scale rotation motion to study more fine-scale gas motion,

[00:06:57] strong rotational motion. And we see clear, coherent pattern, the galaxy's not just quietly rotating but the disk is oscillating like the ripple propagates as the stone being thrown in the pond. So the motion is like vertically oscillating, vertical direction to the disk

[00:07:18] and synchronized motion. So if you see the disk from the edge on, the disk looks like U-shaped, the subtle light shape and bending, the oscillating vertically. Is that what we're seeing with our own

[00:07:33] galaxy where the sun isn't just going around the galactic center but it's also oscillating up and down through the disk as well as it moves? Yeah, yeah. It's a similar thing. Around the

[00:07:46] rotating orbit the sun oscillates up and down and in and out and emulsifies a similar synchronized motion. And then moves upward and downward. We saw similar phenomena in very high-redshift galaxies at early universe. When you look at these high-redshift galaxies, were there a lot of spiral

[00:08:09] galaxies there or not? Actually the spiral structure becomes rarer and rarer at higher redshift earlier universe. And we need to study galaxy with different epochs, different mass, different environment. Different mass galaxy may be different mechanism to form spiral galaxies.

[00:08:32] But this galaxy is very rare at this epoch. This is very rare example, very unique galaxies. So that may give us clues how the galaxy forms, how the spiral structure forms as a very early example.

[00:08:50] Have you had a chance to compare the results you've had with the early epoch galaxies you've looked at compared to what the Webb Space Telescope has seen of early epoch galaxies? This galaxy to be observed with the Webb Space Telescope. So I'm already looking forward to

[00:09:07] the image to be taken. It's yet to be, it's on the list. Okay. And JWST will provide stellar image, not gas image. So it will provide complete view with the ALMA study. It's amazing we can do that

[00:09:20] now, isn't it? Yeah, yeah, yeah. We don't know. We can't expect maybe stellar distribution is pretty much different from the gas or stellar structure. Also show beautiful spiral arm. It's very interesting. We have moved away from individual wavelength observations where optical astronomy

[00:09:39] and radio astronomy were completely different fields almost. Now it's all coming together. And we've got gravitational waves as well, although they can't see that far back in space time. But all these different, these multi-wavelength fields are starting to come together now, which has got to be

[00:09:53] a huge boom for research into astronomy. Yeah, exactly. Yeah. We are living in very lucky era. Yeah. You mentioned that you're looking forward to the James Webb images to complement the ALMA

[00:10:05] images. What about the future? What's the sort of research you want to do next? Yeah. So basically countless number of galaxies are out there. So when we study the gum tree in forest, in whatever

[00:10:17] detail, we cannot understand eucalyptus tree. So to understand the entire ecosystem and dynamics of entire forest, we need to look at the ensemble stuff, I mean trees in the forest. Similarly, so we've got many more galaxies across the different epoch of universe, different mass and environment

[00:10:37] to see if this kind of phenomenon is ubiquitous or how it's formed. And I think Australian researcher is in prime better position to do this because we let unique large survey project called MAGFI

[00:10:51] project look at not that far from what we have found, but a moderately distant universe, breaching the far distance and today's universe, providing the detailed look of galaxies shape and movement and to provide complete picture of how galaxies shape and evolved. And also probably

[00:11:12] for current observation, we can only get the snapshot state of galaxy from observation. And our interpretation of the seismic ripple on the disk is ultimately conjecture in the sense that it is only based on the snapshot observation for just single object. But in this study,

[00:11:31] the numerical simulation played an important role for the interpretation which shows similar pattern what we see in this galaxy. So, other computer simulations including the physical law and galaxy properties informed by our observation can maybe help piece together the exact origin

[00:11:50] and evolution on these phenomena. That's Dr Takafumi Sikui from the Australian National University and this is Space Time. Still to come, a new study looking at what makes up the core of neutron stars and the countdowns underway for the United Launch Alliance's maiden flight of

[00:12:08] its new Vulcan rocket. All that and more still to come on Space Time. A new theoretical analysis is showing further support for the hypothesis that the cores of neutron stars, among the most exotic

[00:12:37] objects in the universe, are composed primarily of de-confined quark matter. A report in the journal Nature Communications places the likelihood of a quark matter core in a neutron star at between 80 and 90 percent. Scientists reached their conclusions through massive supercomputer runs

[00:12:55] utilizing Bayesian statistical interference. Other than black holes, neutron star cores contain matter at the highest possible densities which can be reached in our universe. Think of something twice the mass of our sun compressed into a sphere just 25 kilometers in diameter.

[00:13:14] These astrophysical objects can indeed be thought of as giant atomic nuclei, with gravity compressing their cores to densities far exceeding those of individual protons and neutrons, subatomic particles found in the nucleus of atoms. And it's these incredible densities which make neutron

[00:13:32] stars interesting astrophysical objects from the point of view of both particle and nuclear physics. A long-standing open problem concerns whether the immense central pressure of the neutron star can compress protons and neutrons into a new phase of matter, a phase known as cold quark matter.

[00:13:50] One of the study's authors, Oleski Veronian from the University of Helsinki, says that in this exotic state of matter, individual protons and neutrons would no longer exist. Instead, their constituent quarks and gluons, the elementary subatomic particles that make up protons and

[00:14:06] neutrons, would be liberated from their typical color confinement and allowed to move almost freely. Veronian and colleagues have now provided the first ever quantitative estimate for the likelihood of quark matter cores inside massive neutron stars. They've shown that based on current

[00:14:23] astrophysical observations, quark matter is almost inevitable in the most common massive neutron stars. In fact, a quantitative estimate that the team extracted placed the likelihood in the range of 80 to 90 percent. And the remaining small likelihood for neutron stars to be composed of

[00:14:39] only nuclear matter requires the change from nuclear to quark matter to be a strong first order phase transition, somewhat resembling that of liquid water turning to ice. But this kind of rapid change in the properties of neutron star matter has the potential to destabilize the star

[00:14:56] in such a way that the formation of even a minuscule quark matter core would result in the star collapsing into a black hole. And that's clearly not happening all the time. The research was part

[00:15:07] of a major international collaboration of scientists from Finland, Norway, Germany and the United States. They were also able to show how the existence of quark matter cores could one day either be fully

[00:15:19] confirmed or completely ruled out. The key is being able to constrain the strength of the phase transition between the nuclear and quark matter. And that's expected to be possible once a gravitational

[00:15:32] signal from the last part of a binary neutron star merger is recorded. One key ingredient in deriving the new results was a set of massive supercomputer calculations utilizing Bayesian interference. That's a branch of statistical deductions where one infers the likelihood of different model

[00:15:49] parameters by way of a direct comparison with observational data. The authors had to use millions of CPU hours of supercomputer time in order to be able to compare their theoretical predictions to observations and to constrain the likelihood of quark matter cores. The Bayesian component of

[00:16:06] the study enabled the authors to derive new bounds for the properties of neutron star matter, demonstrating how they approach so-called conformal behavior once you get near the core of the most massive stable neutron stars. It's a fascinating topic and one we may soon find an answer to.

[00:16:25] This is Space Time. Still to come, the United Launch Alliance counting down to the maiden flight of their new Vulcan Centaur rocket, and later in the Science Report, a major revolution in paleontology with some juvenile T-Rex fossils being reclassified into a separate and distinct

[00:16:43] species of small Tyrannosaur. All that and more still to come on Space Time. Well, if all goes according to plan by the time you hear this show, the United Launch Alliance will be in final

[00:17:10] countdown for the maiden flight of its new Vulcan Centaur rocket. The mission was supposed to fly on Christmas Eve from Space Launch Complex 41 at the Cape Canaveral Space Force Base in Florida, but it was delayed due to last-minute technical issues with ground equipment during a recent

[00:17:27] pre-launch wet dress rehearsal test run. On board the rocket is Astrobotic's new lunar lander, which could become the first private spacecraft to touch down on the moon. The new Vulcan Centaur launch vehicle replaces the United Launch Alliance's existing Atlas V

[00:17:44] and Delta IV rockets. The Vulcan's liquid methane and liquid oxygen powered core engine replaces the liquid hydrogen and liquid oxygen core engines used in the Delta IV, while the new Centaur V upper stage replaces the earlier designed Common Centaur and Centaur III variants used on the

[00:18:02] Atlas V. Depending on configuration, the new launcher can carry a payload of up to 27.2 tons into low-Earth orbit, 15.3 tons into geostationary orbits, and 12.1 tons into translunar orbit, making it comparable with SpaceX's Falcon 9. Meanwhile, the European Space Agency have now

[00:18:22] slated a launch window stretching from June 15th to July 31st 2024 as a possible launch date for their new Ariane 6 rocket. ESA's new launch vehicle replaces the Ariane 5, but has been plagued with four years of delays due to both technical issues and the pandemic. Needless to say,

[00:18:42] we'll keep you informed with the launches of both vehicles. This is Space Time, and time now to take a brief look at some of the other stories making news in science this week with the Science Report. There's been a major breakthrough in diabetes research. Australian

[00:19:14] researchers are zeroing in on the ultimate quest to regenerate insulin in pancreatic stem cells and replace the need for regular insulin injections. Researchers with the Baker Heart and Diabetes Institute have demonstrated that newly made insulin cells can respond to glucose and produce

[00:19:31] insulin in just 48 hours following stimulation with two US FDA-approved drugs. A report in the journal Signal Transduction and Targeted Therapy confirmed the pathway is viable in age groups from 7 to 61, providing crucial insights into the mechanisms underlying the regeneration of beta cells.

[00:19:52] Well it looks like paleontologists have finally settled a long-running debate by reclassifying what were previously thought to be juvenile Tyrannosaurus rex fossils into a separate and distinct species of small tyrannosaur. A report in the journal Fossil Studies shows that the new

[00:20:09] analysis of fossils believed to be juvenile T-Rexes now shows that they're actually adults of a smaller tyrannosaur with narrower jaws, longer legs and bigger arms than T-Rex. The new species, Nanotyrannos lancensis, was first named decades ago but later reinterpreted as simply a younger

[00:20:28] version of T-Rex. The first skull of Nanotyrannus was found in Montana back in 1942. But for decades paleontologists have gone back and forth on whether it's actually a separate species or simply a juvenile version of the much larger T-Rex. However, the latest reanalysis of fossils looked

[00:20:48] at growth rings in Nanotyrannos bones which confirmed once and for all they became more closely packed together on the outside of the bone. This means the growth was slowing down and that suggested these animals were already at or near their full size and not growing fast as

[00:21:06] juveniles normally do. Modelling the growth of the fossils showed that the animals would have reached a maximum of around 900 to 1500 kilograms and roughly 5 meters in length. That's about 15% the size of a full-grown T-Rex which grew to over 8,000 kilograms and more than 9 meters long.

[00:21:27] A new study claims that people may enjoy the thrills of horror movies and violent video games because they counter-intuitively make you feel less anxious and stressed rather than more owing to the brain's curious nature. The study's authors say fictional scenes and scenarios are

[00:21:43] actually a source of learning and feelings of being in control for your brain, especially the brain's predictive processing network which uses sensory stimulation to make predictions about future sensory states. A report in the journal The Philosophical Transactions of the Royal Society B

[00:22:00] claims that this means there really is a sweet spot for fear and fun in horror entertainment. But the authors stress this doesn't mean your engagement with frightening media can never take a more morbid turn, with curiosity driven by expectations of horrible outcomes rather than

[00:22:16] curiosity alone. Skeptics have raised the rather pesky point of the contradiction between what ghosts are supposed to be capable of doing and what physics says is actually possible. Tim Mendham from Australian Skeptics says, if ghosts are real and can walk through walls,

[00:22:34] how come they don't fall through floors? The magic of hunting ghosts is a contrast with science, understandably in many cases. The people who go in military camouflaged uniforms in the building at the middle of the night with all their gadgets and that sort of stuff and the gadgets

[00:22:48] which basically don't do anything or can be easily manipulated to try and show something. There's some basic science that is a problem for ghost hunters. He goes through, the author of this goes through and says that there's a range of physics that don't really work for ghosts. For

[00:23:03] instance, light reflects off things. If a ghost is an incorporeal thing that's not really there, how can it reflect? How can you see it? How can it reflect light? The same for if it's an

[00:23:13] incorporeal... It reflects off the sheet doesn't it? Yes, it reflects off the sheet with little holes in them for your eyes, ghost eyes, you apparently can't see through a sheet but can walk through a

[00:23:23] wall. So then the same for sound, how can an incorporeal being make noises? Like you always hear footsteps in the floor above or some sort of thing or thump, thump, thump, whatever

[00:23:34] this thing doesn't have a body. How is it going to make a noise? It can't physically bang something if it has a physical presence, how does it walk through a wall? So there's that sort of stuff,

[00:23:42] thermodynamics, the issue with heat, temperature, all those sort of things. How does it do that? And magnetism, electrical fields, all these things are applied to if something doesn't have a physical corporeal presence. How can it actually affect all these different things?

[00:23:56] Naturally, the ghost hunters come up with all sorts of alternative solutions. Perhaps it's energy is unknown to science. It's quantum. It's quantum and all sorts of things like that, but with different energies it has a way of manipulating phenomena and measurements

[00:24:10] through their special spiritual energy, basically poor explanations, what if sort of explanations, what if? You either got a corporeal thing that doesn't reflect light, can walk through buildings but can knock on things, can't affect electromagnetic fields although they say it does.

[00:24:25] It's got to be an either or situation is what you're saying. Got to be an either or situation and sometimes they want it both ways. They want it both ways by saying these are physical phenomena, physical attributes that ghosts are supposed to have

[00:24:35] and if they can't do them because of physics then we must have an alternative physics. And so you're proposing a particularly tenuous, totally made up sort of solution to what is a serious scientific

[00:24:46] limitation on ghosts. These are standard things. If a ghost can walk through a wall, why doesn't it drop through the floor? How can it come downstairs if it can walk through walls?

[00:24:55] And ghosts can walk through walls. How do they open a door and slam it? How do they knock a glass off a bar? How do they do all these things if they're non-corporeal? And the answer is special

[00:25:05] energy. So you just make up something, you put that at the end and you sort of make up theories to how a ghost can do these things but all science is wrong. Now that's a pretty big jump

[00:25:14] to make that claim but they do. Energy is unknown to science, what we get is called UTF, Energy is Unknown to Science. There's a handy explanation for these answers because it's quantum. It's quantum science because quantum science is weird and therefore it's quantum.

[00:25:29] You just say quantum and it explains everything apparently. That's Tim Mendham from Australian Sceptics. And that's the show for now. Space Time is available every Monday, Wednesday and Friday through Apple Podcasts iTunes, Stitcher, Google Podcasts, Pocket Casts, Spotify, Acast, Amazon Music, Bytes.com,

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