Episode 74: Simulating Cosmic Nurseries
with Professor James Chibueze
Above: Scrolling transcript. See below for static transcript.
This episode of Cosmic Savannah features Professor James Chibueze, a distinguished professor at the University of South Africa, discussing his research on star formation using radio astronomy.
During the episode, Prof Chibueze discusses his journey to become a professional astronomer and how he got interested in radio astronomy. Prof Chibueze also gives some insight into his experience doing his PhD in Japan and even having to learn Japanese. James also discusses his work on studying young spinning stars which produce bipolar outflows.
To shed angular momentum, stars launch outflows of gas perpendicular to their accretion disc, typically from the north and south poles. Using high-resolution radio astronomy techniques, Prof Chibueze’s research revealed that the ejected gas in these outflows is also spinning. This finding suggests that the outflowing gas carries away the star’s angular momentum, allowing it to continue accreting material and grow.
Join us for this deliciously technical episode of The Cosmic Savannah!
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Acknowledgements
Podcast Manager and Show Notes: Francois Campher
Social Media Manager: Sumari Hatting
Transcripts: Abigail Thambiran
Audio Editing: Jacob Fine
And all of our volunteers!
Transcript
Jacinta: [00:00:00] Welcome to the Cosmic Savannah with Dr. Jacinta Delhaize
Tshia: Dr Tshiamiso Makwela
Dan: and Dr. Daniel Cunnama. Each episode we’ll be giving you a behind the scenes look at world class astronomy and astrophysics happening under African skies.
Jacinta: Let us introduce you to the people involved, the technology we use, the exciting work we do, and the fascinating discoveries we make.
Tshia: Sit back and relax as we take you on the safari through the sky.
Dan: Welcome to today’s episode.
Tshia: Hello, hello everybody.
Jacinta: That was enthusiastic. Hi, everyone.
Dan: Tshia is on form today, so we’re gonna let her lead this. Tshia?
Tshia: Oh, well, I’m trying, I’m not really on form. I’m just, you know, trying to be alive in this cold breezy, weather uh, that’s not really nice. So I’m just trying to find some positivity around.
Dan: We appreciate it.
Jacinta: I love it.
Tshia: And I have to spread it to both of you.
Jacinta: Yes, please. We need it.
Dan: No, yeah. I’m, I’m Philippines.
Jacinta: It’s, [00:01:00] uh, it’s quite chilly in our little tiny studio at the moment. Winter is very much in Cape Town. Dan’s wrapped up in a nice scarf. That’s, uh, what? Cashmere? Silk? What you got there?
Dan: It’s from Ethiopia, actually.
Jacinta: Oh, very nice.
Dan: Yeah, it’s very nice. Thank you. I dunno what it’s made out of. Cotton?
Jacinta: Yeah. Let me, let me feel the texture.
Tshia: It, it feels really good. It feels like a good quality scarf.
Dan: When we were there for the Dark Skies and Astro-Tourism Conference, Astronomical Heritage Conference in November, one of the organizers, Mariana Povich, who we’ve spoken to previously on here.
She took us to this community project with these women who could no longer work in the work that they were doing, which was hard to talk about collecting wood. Once they became too old to collect wood, they started this little organisation where they make scarves and other cloths and things. So we went in and saw this and met them and watched them making these fabrics on traditional… [00:02:00] looms? I think they’re looms.
Jacinta: Oh, really? Wow.
Dan: Yeah. And yeah, and then they had a little shop there and, yeah.
Jacinta: Oh, cool. I was just about to ask where came from? How do you make a scarf? Wow. Looms.
Dan: So this is, this is handmade.
Jacinta: Awesome. That’s really nice. Yeah.
Dan: Nice little diversion there.
Jacinta: There we go. Well, we do talk about African astronomy, and that was about Africa.
So now we can get onto the astronomy part. Today’s guest is Professor James Chibueze from the University of South Africa- UNISA.
Dan: UNISA, yes.
Tshia: Yes, it’s UNISA.
Dan: Jacinta has this thing when she warms up her voice where she goes, unique New York. And I thought that she just slipped back into that when she said UNISA.
Tshia: It did sound like that when you went “u-NI-sah”.
Jacinta: Unique, New York. Unique, New York.
Dan: There we go.
Jacinta: Yeah. Can you say it? Fast?
Dan: Unique New York.
Jacinta: See, it takes some time.
Dan: It’s difficult. Okay. And our second diversion for the day. Back to business. So Jacinta spoke to Professor James [00:03:00] Chibueze who is at UNISA as, as Jacinta mentioned, and he is a professor there and I think we all know James. You know, from the astronomical community. He’s, uh, been around for some time and also is involved in many different things. Currently I’m working quite closely with him, with the organization of the, the General Assembly in August, he’s leading the science committee there, so having regular meetings about that.
I know you guys, uh, have, have also come across him in the past.
Tshia: Yeah, I think one of the things that make James quite popular is the amount of work that he’s done with young astronomers within the country, such as running the DARA project, which he did while he was a professor at Northwest University in Po…
Dan: What does DARA stand for?
Tshia: So DARA stands for Development in Africa with Radio Astronomy. So these projects have been currently going around in different African countries. I think the, the last one was in Kenya, but James ran one when he was still at the Northwest University in Potchefstroom, and it does invite a lot of students from across [00:04:00] African continent to come and do some astronomy projects, ,build stuff. I think at Northwest they actually built some small radio telescope, which was really quite cool.
Dan: I recently saw that DARA just got funded again for the next, I don’t know how many years, but uh, to quite a large degree, so
Jacinta: Yay.
Dan: Uh, there’ll be a lot more DARA developing projects.
Jacinta: We could do a DARA episode.
Dan: We should do that.
Tshia: We should,
Jacinta: we haven’t done one yet, have we?
Dan: Have we? No,
Jacinta: I don’t think so. We must,
Dan: We shall
Jacinta: anyone from DARA who’s listening to this reach out to us. We’d love to do an episode with you.
Dan: Alright, Jacinta?
Jacinta: Yes. So basically getting back to the chat I had with James, I found it super interesting.
He’s a hotshot radio astronomer in South Africa. He works a lot on VLBI, very long baseline interferometry, which is basically using radio telescopes all around the world, connecting them up so that you can get amazing angular resolution. So you can see very, very, very small regions with the radio telescope.
And James is using this to look at small tiny areas [00:05:00] in the Milky Way, that are forming stars and he’s learning all about the physics of the formation of stars. And I asked him so many questions and we went into a lot of detail. Sorry if it’s a bit of a deep dive for you listeners, but I was fascinated ’cause this is actually stuff I need to know in order to teach my students.
And there was a whole bunch of stuff that I didn’t know, so I was like, oh, tell me more about this. And so we did. It was a bit much, I don’t know,
Tshia: I must say that, listeners are looking forward to really an episode full of analogies. So these are things that you can actually imagine like, you know, these are a lot of things that you can, imagine and probably try.
Jacinta: Yeah. So stay tuned for like, we do a lot of deep science explanations, but then wait for it ’cause then we’re gonna get to the like analogy afterwards. We do the analogy. So, you know, if it’s not helpful, at least we’ll be entertaining. I’m sure.
Dan: Maybe we can title this episode. Acronyms and analogies.
Jacinta: Yeah maybe!
Dan: Alright.
Jacinta: Um, yeah, and then James also talks about this, you know, radio galaxies are what I work [00:06:00] on and you know, I thought this was the safe region where I was in my lane and James was in his star forming lane. But no, James decides to take over my lane as well.
So he’s also yeah, into studying radio galaxies and why the jets are bending and magnetic fields and all of this stuff.
So he tells us about some of his, he tells us about his Nature paper, which if listeners aren’t familiar with Nature, it’s the kind of one of the holy grails of academia in science and you really want to publish your paper in Nature. That’s the highest quality journal. So James did that and he’s gonna tell us all about his discovery.
So what do you reckon? Shall we hear from James?
Dan: Yes, please.
Tshia: Yes, please.
Jacinta: With us now is Professor James Chibueze from the University of South Africa. Welcome to the Cosmic Savannah James.
James: Thank you, Jacinta.
Jacinta: I’ve been trying to get you on the Cosmic Savannah for several years. We did actually interview you several years ago, but there was something wrong with the audio and we couldn’t use it, so I’m so glad that we finally got you.
James: Yeah, it’s it’s [00:07:00] nice to be back here so I can say more things.
Jacinta: So we’re not in the nice studio at the moment, but we are at a conference at the SARAO Bursary conference. So that’s the South African Radio Astronomy Observatory, which kind of runs MeerKAT, and some other telescopes. And we are here for, you know, a nice long week conference with all of the students and, um, postdocs who work on MeerKAT.
And this is my first time at this conference as a supervisor, but I’m sure it’s not your first time. But James, before we get into all of that, tell our listeners a little bit about who you are, where you’re from, what you do.
James: My name is James Chibueze I’m a distinguished professor at University of South Africa now leading a group, a small group of radio astronomy students.
We call it astronomy niche area. Our focus is on doing SKA science, SKA square kilometer array. I’m originally from Nigeria, I did my bachelor degree at the University of Nigeria in the Department of Physics and [00:08:00] Astronomy. So I have, um, a first class in physics and then proceeded to do a master’s degree in the same university and department in astrophysics.
And then afterward secured Japanese government scholarship, which is called the MEXT. MEXT is just a word for ministry of science, culture, uh, technology of Japan. And the scholarship requires that you study in Japan. So
Jacinta: Wow.
James: So, which means you have to find a Japanese supervisor in a Japanese university, and you can only use that, you know, in the country.
Jacinta: Wow. So you did your PhD in Japan?
James: Yes, I did.
Jacinta: Oh my good. Do you speak Japanese?
James: Yeah, I can teach astronomy and astrophysics in Japanese.
Jacinta: What you can teach? Astrophysics in Japanese?
James: I did my PhD VI in Japanese.
Jacinta: Wow, okay. That’s deeply impressive. And now I have massive imposter syndrome. Alright, well that’s awesome.
Okay, [00:09:00] so like I know you’ve had this, this long and illustrious career ever since then, and yet you are about the same age as me and I’m not jealous at all. It’s fine. But first of all, okay, tell us about the experience of doing a PhD in Japan and, and then also tell us what you were working on.
James: Well, the, the experience was good.
I wanted to do radio astronomy because I had heard about the African VLBI network. This was just in the early days when it was being muted that there will be a VLBI network that would spread the knowledge of radio astronomy to the rest of Africa partner countries for the SKA host bid. Yeah, so VLBI means very long baseline interferometry.
It is simply using two or more dishes to observe the same source at the same time. They’re separated by a distance, but in this case you’re thinking about the distance that is extremely long.
Jacinta: So this is two radio or radio telescope dishes. Telescope, yes. Separated by some distance on the [00:10:00] ground, but by a very long distance,
James: yes.
So like putting a dish in Kenya, for example, and another dish in South Africa, you would get a baseline, or the separation between the two telescopes will be roughly 6,000 kilometers. If you use that to simultaneously observe a source, you’re doing VLBI. So I was keen to do VLBI and I ended in Japan working with the famous Japanese VLBI network called the VERA. VERA means VLBI, exploration of radio astrometry. Astrometry is just how we measure distances to sources in the sky.
Jacinta: Yeah, there’s a lot of acronyms in astronomy, right? It’s so hard to say. Even one sentence without like 10 acronyms.
James: Yes.
Jacinta: So you went to Japan to start work and it’s related to the African VLBI network.
So the fact that there is plans to put these radio telescope dishes in different African countries in order to combine with the eventual SKA [00:11:00] telescope and therefore to have very high resolution images to be able to take really, really crispy images of the sky at radio wavelengths, right?
James: Yeah, exactly.
So the idea was to acquire the skills from Japan and then use it in Africa. And that’s exactly what I did. I did study star forming regions within our own galaxy. Places where the birth places are very big stars. When I say big stars, they are typically stars that are eight times the mass of the sun and above.
So if you imagine the sun being 10 to the power, 30 kilograms in weight, I’m sure you can. It’s almost unfathomable. Then if you multiply that by eight, that’s the size of the smallest, massive star we know. Anything less than that we consider to be intermediate mass or low mass star.
Jacinta: Okay, so the sun, the sun’s an intermediate or like small guy?
James: A low mass star.
Jacinta: It’s a low mass because it’s just a little teachy one.
James: We actually call it the yellow dwarf star.
Jacinta: Oh, a dwarf, really? [00:12:00]
James: Yeah. So I studied how big stars are formed, going all the way from the gas and dust in a cloud that make up the star. So because they are nearby, well, you would want to have very high angular resolution to see all the details of the motion of the gas.
So VLBI will give you that resolution because you have a very huge separation between the antennas or the telescopes. So your angular resolution come down to milliarcsecond level. Don’t worry. I will explain that soosoon. When look at an object, what we actually see is in angles.
Jacinta: Mm. On the sky. Right.
James: So on the sky. Yeah. And if you imagine one degree to be very small, and you project one degree to a very long distance, that becomes a huge chunk of the sky. And you can have hundreds or thousands, or hundreds of thousands of staff forming region within that small space.
Jacinta: Really? Yes. Within this tiny, tiny little patch of sky.
James: Yes.
Jacinta: Wow.
James: So typically you would [00:13:00] have one degree is equivalent to 60 arcminutes. And one arc minute is equivalent to 60 arcseconds.
Jacinta: Okay, so like a clock and you’ve got 60 minutes. And that’s in one, we call it a degree, but in this analogy it would be an hour. Yeah. And then you’ve got 60 seconds in each minute.
Right. And so we, we split the sky up in terms of angles and we split those angles into degrees, into minutes, into seconds. Okay. So, so, so an arc second is the smallest unit there, right? So that’s tiny.
James: So even within an arcsecond, you can have at least 10 to hundred massive star forming objects.
So, which means we need to go even further to break down one arcsecond to smaller scales to be able to study one of those star forming regions or star forming cores in detail.
Jacinta: Okay. And so like just for comparison, if you put your thumb out as far as it goes. And you pointed it up at the night [00:14:00] sky, that’s about what, half an, half a degree?
James: Yeah, roughly half a degree.
Jacinta: Okay, so that would be 30 arcminutes. Which is 30 times 60 arcseconds. And you’re saying that there’s hundreds or thousands of star farming regions within an arcsecond. Wow. Okay. So lots and lots and lots and lots.
James: Good. So we need milliarcsecond scale, which is 1000 of an arcsecond, and even micro-arcsecond scale, which is hundred, well, about a million of an arcsecond scale to find details of the gas structure. And gas motion. That’s why we need VLBI.
Jacinta: Okay, so we’re, we’ve got arcseconds, we understand what that is now. And then we are breaking that down even smaller into milli-arcseconds and then smaller into micro-arcseconds. And there’s a million micro-arcseconds in one second.
Okay. So we’re looking at teeny, teeny, teeny, teeny, teeny patch of sky. And to do that we need a telescope with extremely good [00:15:00] resolution.
James: Absolutely. Okay. So that’s, that’s why you need very long baseline,
Jacinta: Yes. That’s why we need VLBI. So we need to make the size of our telescope basically the size of the earth.
Right. More or less,
James: yes, we do have that already. As you know, we have what we call the global VLBI network. That you can achieve a baseline of about 11,000 kilometers, which gives you an excellent resolution to study objects.
Jacinta: Okay. So now let’s talk about the star forming regions. So as the name suggests, I’m going to assume it’s a region in the Milky Way.
James: Yes.
Jacinta: Where stars are forming.
James: Exactly.
Jacinta: Good. I nailed it.
James: Yes, absolutely.
Jacinta: So explain to me what is in these star forming regions.
James: So if we’re fortunate to be in South Africa where you can go to some dark areas and you look at the sky and you’ll see the Milky Way. With your own eyes, if you look closely at the Milky Way, you will see bright spots, [00:16:00] which are just regions where you have middle aged stars that are shining and giving out light, but you also find a bunch of dark lanes. Uh, those dark lanes represent regions where we have a lot of dust.
Jacinta: So it’s like the, the dark patches in the, the dark patches along the, the, along the Milky Way.
James: Yeah. Yeah, exactly. So those are the natal. By Natal I just mean regions where the stars are born.
Jacinta: Mm. What do you call it? Nettle?
James: Yeah. Like star forming regions. N-A-T-A-L.
Jacinta: Oh, like natal, like as in Yeah. Where something’s born, birthplace. Got it, got it. Cool.
James: Yeah.
Jacinta: So these dust lanes are the birthplace. Okay.
James: Yeah. So the, the dust we talk about are just similar to the dust we see on, on the surface of the earth. They are mostly carbonate materials and silicate materials. They are produced mostly by dying stars, and then they are recycled and used again to form new sets of stars. [00:17:00] So the dark lanes are just because you have dust particles and everything shining from behind it.
The lights coming from the back are all absorbed. Just think about it, that you’re driving behind a rickety vehicle that is chunking out black smoke.
Jacinta: Okay?
James: Your visibility will be obstructed due to the black smoke, not because the objects ahead are not reflecting light but because the lights reflected by those objects are absorbed by the dark smoke, produced by the vehicle ahead of you, then you don’t see anything.
Jacinta: You have to, so yes, you may. So that vehicle may have its lights on and have bright brake lights, but you are not gonna see it because of the dark smoke and then you might ram into the back. But that’s where the analogy ends.
James: Exactly. Exactly. So that’s what we see in the Milky Way, but those are really crucial parts of our galaxy, because that’s where all the new stars forming within our own galaxy have been born.
So typically you have gas and dust mixed together. They [00:18:00] have, they’re typically extremely large. Their masses are as big as sometimes thousands, hundreds of thousands of solar masses. That’s just, we use solar mass in astronomy to describe the mass of the sun. And we use that as um,
Jacinta: a unit.
James: Yes, A unit, to classify other more massive objects.
Jacinta: Oh, so like a measurement. So it’s like 100 – 1000 times the mass of the sun.
James: Yes.
Jacinta: Yeah.
James: And mass of the sun is 10 to the power 30 kilograms.
Jacinta: Okay,
James: good. So in this region, the distribution of the gas and dust, it’s not uniform. It’s not homogeneous. So they’re
Jacinta: clumpy.
James: It’s a bit clumpy. And therefore, gravitational law will kick in because you have sub structured materials that are of different masses and therefore they can collide and,
Jacinta: right, because the more mass, the more gravity.
James: Exactly.
Jacinta: So then if you’ve got regions that have more mass because it’s clumpy, they’re gonna have more gravity. So then stuff’s gonna fall into that region and get more and [00:19:00] more dense. Right?
James: Exactly. So when you start, if you have gravitational collapse, you start forming things like high density cores.
Jacinta: Is that called a bok globule?
James: No, that is called cold cores.
Jacinta: Okay cold cores.
James: Yes. ‘Cause they’re extremely low temperatures. They’re typically between 20 and 30 Kelvin.
Jacinta: So you said about 20 to 30 Kelvin. Then, then that’s very cold. What, what does that mean in like degrees Celsius?
James: So 20 Kelvin is equivalent to minus 253 degrees Celsius.
That is extremely low temperatures,
Jacinta: very cold. Very, very, very cold. Okay, so like way colder than it gets on Antarctica or anything?
James: Exactly.
Jacinta: Okay.
James: You need that cold temperatures because the dust need to be so cold that the gas gets frozen onto the dust. Oh. Therefore, when it starts, starts to form, you have high density in the core. There’s a lot [00:20:00] of collision. The temperature starts to rise.
Jacinta: Oh,
James: the increase in temperature impacts the dust will absorb the photons or the heat that comes from increased temperature in the middle. And the gas that is frozen onto the dust grains will be released.
Jacinta: It like evaporates.
James: Evaporates. And then we can detect it because the release of the gas means that they will generate radio waves, which you can detect with telescopes.
Jacinta: Really? I did not know that. This is so exciting. Okay. As you can tell, I study galaxies and I know nothing about this. Um, but interestingly, I do have to teach galactic science, so I am glad that we’re all learning something today and I’m probably gonna tell my students to listen to this episode.
James: Yeah, that will be cool.
Jacinta: So, hi to my third years, if you’re listening to this in the future, this is, uh, this is where I learned it in the first place. Okay. So you’ve got in these really cold cores in this star forming regions, you have this really, really cold area. You’ve got gas that has now like frozen onto [00:21:00] dust particles and which is basically like thick smoke.
James: Yes.
Jacinta: And then once it gets dense enough, it starts to heat up because of like these particles are starting to collide with each other. And then the gas evaporates and when it releases off the dust, it emits a signal. And it like emits some radio light.
James: Radio wave, which we can pick up.
Jacinta: Yeah. So, so why does it emit radio waves?
What happens there?
James: Well, every molecule of course atoms, for example, hydrogen atom would neutral hydrogen emits when you have a change in spin direction of the electron.
And the proton. So the direction typically spin the same direction. But if you have a change in the spin direction, it releases radio wave.
Jacinta: This is like a weird quantum property of electrons and protons, which doesn’t really have an analogy in real life, but we just call it a spin direction. Okay.
James: Yes. So in the case of molecules like carbon monoxide, which is one of the simplest one, the bond between the carbon atom [00:22:00] and the oxygen atom is not static.
It does vibrate. Okay. So we have vibrational state of emission, which is for vibrating molecule. There are also molecules that are, we call polar molecules that like ammonia, which have one atom of nitrogen and three atoms of hydrogen. This has some angle, it makes some kind of angle that you can trace.
Uh, you can cut into two and then you have asymmetry. Such molecules sometimes rotate.
Jacinta: Okay.
James: So we have rotational transitions and those are transitions emissions that come due to the rotation of the molecule.
So you have vibrational emission. And you have rotational hyper emission. One molecule can have multiple of these depending on the conditions of the environment.
Jacinta: Is this called row vibrational?
James: Yes.
Jacinta: Transitions? Yes. I nailed it. Okay. So this is exciting because I learned about this [00:23:00] recently when I had to teach this, this course. Yeah. And I had never heard of this before. So molecules can vibrate and that emits light. And they can also rotate. And that emits light and they can rotate and vibrate at the same time.
And that emits light. Yes. Cool. Alright. And so then that’s emitting this, this light at, I’m gonna assume this is what? Millimeter wavelength. Sub-millimeter wavelengths.
James: We can also find some spectral line at centimeter wavelength.
Jacinta: Okay, so radio telescopes, millimeter telescopes, those sorts of things?
James: Yes.
Jacinta: Okay, cool. All right, so you’re studying these star forming regions. You’re, you’re studying these molecules that have just been released from the dust and they’re starting to vibrate. I know this is getting a little bit further away, but like what happens next? How come it starts off as this cold, cold, cold region?
How does it suddenly get to like really hot and start forming stars ?
James: So the star, continues to accrete. The beauty in looking at star forming region is that you find something super interesting, which is that the star continues to [00:24:00] swallow up more gas. To grow in its mass and at the same time it does spin around, so has some angular momentum, which you cannot sustain.
Jacinta: Mm.
James: You can’t keep spinning
Jacinta: faster and faster. Faster, infinitely faster without, yeah.
James: Without releasing some of that angular momentum away. Otherwise you have a catastrophe. So lemme put an analogy. If you pick up a string and tie, say a stone to one end and hold it in your hand and spin it around.
If you spin it endlessly, you generate an angle of momentum that needs to go away. But you keeping hold of it in the system. You would realize that if you spin it 400 years, even if you’ve used a metallic string, that is going to rip off.
Jacinta: Right
James: okay. So the angular energy you generate needs to go away, otherwise it becomes very destructive.
That happens in star formation. The star is, the core is spinning [00:25:00] around and has a disc, and is accreting material as a result of the spinning process. We call it accretion.
However, it cannot continue to accrete without taking away some of the angle and energy.
Jacinta: So when you say it means like grow bigger and eat more, bigger stuff around it.
Bigger, yes. Yeah.
James: So it eats more stuff, but due to the spin, the angular momentum you generate, you also need to give out, you have
Jacinta: to lose energy somehow.
James: Yes. Okay. You have to lose the angular energy somehow. So forming stars launch what we call outflows, through the poles. So around the plane is the disc, which is typically fairly thick. But from the poles, well it does eject material all around in three dimensional shape. But around the disc you have some thickness. And therefore it’s difficult for things to escape from there. So you see things escaping from the poles.
Jacinta: Okay. So if you think of like Saturn which has a ring around it. That’s like the disc [00:26:00] area. And then the poles would be like directly above and below, like in the north.
James: perpendicular to the disc,
Jacinta: the north pole and the south pole of Jupiter perpendicular to this. So sorry. Saturn- did I say Jupiter or Saturn?
I meant Saturn. Saturn has a ring. Okay. Yes.
James: So, so. We call that bipolar outflow.
Jacinta: Bipolar outflow. Okay.
James: Yes. Because it goes out through the north and the south pole. And the disc is around the perpendicular direction. So you will see this in many star forming regions, and that’s one of the things we used to identify a forming star we know is in the early formative stages.
And it would have that accretion disc and will have bipolar outflow. And my study was focused on using high resolution image to look at the inner part of the outflow, to find those extremely collimated gas that is just being ejected by the star. And it wasn’t my time. We discovered that the outflowing material is actually spinning around and going [00:27:00] outward.
That is evidence that the angular momentum from this rotation of the disc is being carried away through the outflow, therefore the star can continue to feed.
Jacinta: Oh wow. That’s so cool. Let me guess, is this called a precessing flow or something?
James: It’s slightly different from precessing. Precessing is, is part of it to some extent.
Processing is when you do, okay, now I need to demonstrate.
Jacinta: Okay. Now you need to do this visually. Okay. Yes. So, so, so James is like moving his arm in a twisty, weird way. Which I have no idea how to describe that.
James: Yeah. So, so if you watch these movies where people try to spin around a stick in a fancy way where you can rotate it around so the outflow is not just stationary, just keeps turning um, in, in this rotating direction. So sometimes you see it here on the other time, this not on side. The not on side of the outflow is to the left or it is to the right. It [00:28:00] just keeps going.
Jacinta: So imagine oh, like a, like a, what do you call these things?
A spinning top. You know, when you, when you turn that
James: Yeah. When it’s about to
Jacinta: and when it’s about to topple over. And it like starts to, to wobble. Oops. That’s, it starts, I just, sorry, I hit the microphone with excitement. So it starts to wobble because it’s like, you know, it’s,
James: that wobble part is the stick part is wobbling.
Yeah. Yes. That’s the precession.
So you consider the wobble of the stick as precession, but the, the
Jacinta: spinning?
James: Circular motion is actually the angular momentum. The outflows carrying the angular momentum. So that’s a good example.
Jacinta: There we go. There we go. We’ve, we, that was teamwork.
We’ve come up with a great analogy we should always use from now on precessing jets and spinning tops. There we go. Cool. All right. So just to summarize all of that, you’ve got this like, cold region and inside it, the gas is starting to evaporate and now it’s triggering hydrogen fusion. So the fusion of two hydrogen atoms?
No, no?
James: Not yet.
Jacinta: Okay. So it hasn’t started that yet.
James: So we started from dense cloud
Jacinta: Oh yeah. [00:29:00] Dense cloud
James: inhomogeneous, in densities. And then we went all the way to gravitational collapse.
Jacinta: Okay. So now it’s getting, like this runaway effect almost of like getting denser and denser, where, where more and more matter of more of this dust with a frozen, gas onto it is like clumping together. It’s getting really clumpy. And as it’s doing this, it’s rotating. It has what we call angular momentum, which is just movement in a, in a rotation direction. So it’s rotating, and as it gets more and more and more mass, it’s rotating faster and faster.
But what you were saying was that it can’t get infinitely fast. It can’t rotate infinitely fast, so it has to lose energy somehow as it continues to like what we call accrete or like get more material like spinning together. And we didn’t really know how it lost angular momentum in the past. But during your PhD you figured out that it’s losing it through these, what we call outflows, where there’s some kind of, is it gas or is it light or,
James: yeah, it’s [00:30:00] gas.
Jacinta: It’s gas. Okay. So there’s gas being ejected out of the poles, out of like the North pole and the South pole of this like protostar, I guess.
James: Yes. It’s a protostar.
Jacinta: It hasn’t, hasn’t started being a star yet. Baby star or like yeah fetus star. And then, and then you found with this VLBI so like very high resolution astronomy, you found tiny, tiny, tiny little wobbles in these outflows. And that proved that that’s how angular momentum is getting lost.
That’s how the energy is getting lost.
James: Yes.
Jacinta: And then therefore, we don’t break physics.
James: Yes. So you continue to follow physics law, which means you don’t keep the angular momentum in the system infinitely. You’re able to carry it away from the system, but the angular momentum is not stored in the system infinitely.
So you need to carry it out of the system to some extent, so that the star can continue to accrete and grow in mass. So technically what stars do is the same thing humans do. We eat, we excrete, we grow. [00:31:00]
Jacinta: Okay.
James: So you cannot excrete more than you ate.
Jacinta: Mm-Hmm.
James: So stars accrete material from each environment, from the available reservoir of gas and dusts.
But they also excrete by ejecting some of the materials in bipolar outflow. But the outflow rates is lower than the inflow rates. Or their acquisition rates.
Jacinta: That’s why it can still grow
James: then it can still grow in mass. So this will happen for, for high mass stars. The, the one of the key interesting thing is that they, their evolution is very fast.
Jacinta: They live fast, die young, right?
James: Yeah. Big things. Um, live faster life and die quickly. So compared to the sun, which is about 4.5 billion years old, massive stars will evolve within a few million years. That is really very short. So they still stay in accretion phase. And they start burning [00:32:00] hydrogen.
Jacinta: Oh.
James: And they keep accreting, but the attrition rate is so small that compared to the combustion rate, and then they can exhaust the hydrogen so quickly and they expand and then suddenly explode in supernova explosion and die.
Jacinta: Oh, right, because we’re talking about high mass stars. So we’re trying to form stars.
We’re talking about stars forming, and these stars are many times bigger than the sun. So if the sun was forming, then once it starts rotating and it’s forming, then eventually it stops growing. It kind of like blows all over the neighborhood. Material away.
James: Exactly. As soon as it starts to burn hydrogen, the radiation pressure is too strong.
It blows away the remaining uh, formation material. And you will have a star that is shining on its own. There will be a few particles of dust. Around the disc, but the rest of the gas is mostly blown away.
Jacinta: And those, and those particles form planets, right? [00:33:00] Like the earth? Sorry, stole, I stole your, your key, your um, your mic drop moment.
I was just too excited.
James: No problem.
Jacinta: Okay. Alright. But then the high mass stars, they, they don’t blow this material away yet. They keep accreting, they keep growing.
James: Yeah. That’s the mystery behind high mass stars. We don’t know why even when they get into main sequence and start burning hydrogen, they still continue to accrete.
This is still a mystery. We don’t know why.
Jacinta: Okay, so they’re no longer baby stars. They’ve, they’re real stars now. They’ve become real stars. They started burning hydrogen, but they’re still growing.
James: Yes.
Jacinta: And we don’t know why they’re still growing. Ah, that’s cool.
James: So if you solved that problem, you would’ve solved one of the big problems of astronomy
Jacinta: Nobel Prize.
James: Maybe.
Jacinta: Yes. I wouldn’t put it past you. Okay. So then they, they continue to grow. They end up as these really massive high mass stars. And then because they’re burning their hydrogen so fast, [00:34:00] they just run out of fuel really quickly and then they explode in big super over explosions. Okay. Cool. Okay, so I think that we’ll have to stop the discussion of high mass stars there because I have so many questions, but I think I’ll keep asking you once we turn the recorder off, because we’re getting into a lot of detail.
And I don’t know if the listeners have already stopped listening. Sorry if you have, but speaking of big discoveries, I wanna completely jump topics now because I know you have to run away in a minute and I wanna talk about the holy grail of astronomy and our careers is trying to get a, a paper published in Nature or Science.
These are the big journals, the really like famous journals. And it’s like once you do that, you’re career set. Now James, I happen to know that you recently had a, your very own first author paper published in Nature.
James: That’s correct.
Jacinta: Congratulations.
James: Thank you.
Jacinta: Alright, so tell us what this paper was about.
James: Okay. Maybe the background of the story is moving away from high resolution with [00:35:00] VLBI after my jobs in, uh, Japan and back home in Nigeria for a short while, and then to SKA and then to Northwest University. And before moving to UNISA I realized
Jacinta: as, as a brief summary of all the, the career along the way.
Yes. Okay.
James: Yeah. So coming to South Africa, I thought, okay, there is no VLBI network. Of course, the African VLBI network is still up and coming, coming along, hopefully well enough. Uh, but the MeerKAT is an excellent instrument. Fantastic sensitivity. I mean, going down to what we call four micro-janskys per beam, um,
Jacinta: what does that mean?
James: That that simply means that you can detect
Jacinta: very faint signal. Signal,
James: very faint radio signal. Yeah. I’m trying to find a good analogy that could be equivalent to detecting the power generated by a single snowflake on the surface of the moon.
Jacinta: Wow. [00:36:00] Okay.
James: So, so that’s how sensitive MeerKAT is, and I just could not go past using such instrument.
However, the resolution is not as good as
Jacinta: VLBI?
James: VLBI
Jacinta: you, so you’re a bit spoiled there.
James: Yes, I agree with you. Yeah, I was spoiled for resolution, so. If you have poor resolution, you want to go to things that are further away. That’s how I started off to look at other objects. The principles are the same.
It’s the same in interferometry. So I started looking at distant objects. Extra galactic object with Jacinta that will be very happy to hear that I do now.
Jacinta: Yes. Now,
now we are getting into my field.
James: Yes. So I managed to look at an object that is called Abel 3376 this is a cluster of galaxy.
There are two of them that are merging together and they do have one very bright radio galaxy that shows an interesting morphology. So the [00:37:00] original science idea behind the proposal that I submitted to do MeerKAT observation was to look at how particles are re-accelerated at the edges of a galaxy cluster.
So we have something you call radio relics. It’s just radio emission generated by particles at the edges of the galaxy clusters that are re accelerated by energies coming from the center of the galaxy clusters.
Jacinta: Okay, so you’ve got a cluster of galaxies. So just lots of galaxies clustered together as the name suggests.
And then you’ve got, between these galaxies, you’ve got like a soup of hot gas, gas, right? Yes. And that that gas is obviously made of particles. Yes. And you’ve got electrons in there as well. You know, they’ve got electric charges and then for some reason these electrons are getting a big boost and they’re starting to move really, really fast.
And they’re releasing some radio light as they do that.
James: Yeah.
Jacinta: And so we wanna understand why they suddenly get this boost.
James: Exactly.
Jacinta: Okay. Why did they get this boost? Do we know yet?
James: We do have an idea. [00:38:00] We think the reacceleration of the particle, the, the energy you need to do that come from the center of the emerging galaxy clusters.
Jacinta: Hmm.
James: So that was the original science goal. But when I made the images from my MeerKAT observation, I found a galaxy that looks extremely strange.
Jacinta: Extremely strange. Okay.
So radio galaxies are, what’s the s part called? Active Galactic Nucleus. It’s just a galaxy that is launching this fast jet from the poles.
James: Remember I talked about outflows? Bipolar outflows. The jets are also bipolar. They go from the posts. The disc of the galaxy is usually perpendicular to the jets
Jacinta: and that, but they’re originating from a super massive black hole.
James: Black hole. Yes. I. We actually have a name for the black hole, or the galaxy that I refer to is MRC 0600-399.
That’s, that’s very technical. I know.
Jacinta: Well, that’s a very interesting name. Not really.
James: So. [00:39:00] So typically what you find of Radio Galaxy is that they have two lobes of jets, one to the North Pole, the other one to the south pole of the galaxy. But in the case of the second brightest galaxy member in the cluster observed it had a U shape.
If you turn U clockwise by 90 degrees,
Jacinta: it makes a C. Sort of,
James: yes. Sort of C.
Jacinta: Okay.
James: That’s what it looked like.
Jacinta: Okay. So you found like a C shaped radio galaxy.
James: Yeah. It, that’s so weird. So if you stretch out the ends of the C and it stays in a straight line, that’s how weird he was. So, which means that the jet is launch perpendicular going north, south direction and then bent by 90 degrees to the left.
Jacinta: So it’s almost like if you put your hands out from your, like from your shoulders, you put your arms straight out in either direction. And now you bend your [00:40:00] elbows
James: Exactly.
Jacinta: So that your hands are kind of perpendicular to your arms.
James: Exactly.
Jacinta: And now you’re making this weird U shape, but it’s kind of a C shape thing.
James: Yes.
Jacinta: So that’s what the jets of this radio that’s looked like, look like. So they’re meant to shoot out directly from your arms? Straight, straight out. But then they, they were doing that and then for some reason the end of them bent. Bent in a weird 90 degree angle. That’s so strange.
James: Yeah. That is very strange.
So if you look at that image and you’re an astronomer, the first thought will be well, the north-south moving lobe of the jets is definitely from the black hole.
Jacinta: Mm-Hmm.
James: Okay. But the bend direction could be something else. So maybe there is another galaxy locking in the background that you are seeing the jets from.
So my first job was to look at, hey, what is this? Is there any other galaxy within the vicinity? And I looked through all the other wavelengths. There was nothing.
Jacinta: There’s no other galaxy. No other galaxy. Okay. There’s no other [00:41:00] galaxy interacting with it. Causing some weird bending. Can I guess something?
Yes. Yes. So. Because this is my field. I always look at these weird radio galaxies. But a lot of the, these bending is because the galaxy with the black hole in it is moving through this like hot intra cluster medium, the, like the hot soup within the cluster.
James: Is that what you guys call ram pressure?
Jacinta: Yes.
James: Okay, good. So that was, that was what everyone would guess. But
Jacinta: And it’s like blowing, blowing the jets like in this direction.
James: Good lemme surprise you why?
Jacinta: Okay. Okay. So it’s not that. Okay. Alright. I’m interested.
James: So let me, let me surprise you. The bending direction of your arms, of your elbow
Jacinta: Yeah.
James: Is rather moving against the ram pressure direction.
Jacinta: Wait, what?
James: Yes.
Jacinta: So we know that there could be some ram pressure, so it’s like, if I can give an analogy of my own. If you’re like, you’re swimming in the sea. Yes. That’s like you are swimming through this, this hot gas that’s between the galaxies and this cluster, right? Yeah. And I, I happen to have long kind of thin hair.
Which is [00:42:00] like soft. And so if I’m swimming through it and my hair’s out, it’s all gonna be swept backwards off my head. Backwards. That’s like the equivalent of ram pressure.
James: Ram pressure, yes. Right.
Jacinta: So it’s like my hair is all streaming backwards. So it’s like the jets should go streaming backwards.
As it’s moving through this like
James: rather in these jets,
Jacinta: but now it’s in the other direction.
James: Your hair is swimming forward. Yes.
Jacinta: Can you imagine swimming
James: against, against the ram pressure
Jacinta: swimming through the sea and your hair’s going forwards in front of your face that that doesn’t make any sense?
James: Yes, there is more to it.
Jacinta: Okay.
James: So first the jet is bending against ram pressure, which is unexpected. And second, if you have ramp pressure pushing against your hair, you cannot keep it streamlined like you plated it or you braided it. Mm. But these bent jets actually stayed collimated for more than 100 kilo parsec.
Jacinta: What? So they They went straight out from your shoulder to your [00:43:00] arm?
Yeah. And then they bent. But that bent bit also stayed straight.
James: Stayed straight. And collimated
and collated. Like staying in like a really straight like pencil shape.
Jacinta: What? Dude, that is so weird. Yeah.
James: So that’s not all.
Jacinta: Oh, there’s more. Wait, there’s more.
James: So in the bent arm that you have, there is also some tiny bit that came backward.
Jacinta: Okay, so James is pointing to his elbow? Yeah. He’s got his, his arm bent. Bent and, and he’s pointing to his elbow and he’s making his hand go away from his elbow in the opposite direction of his arm. Yeah. Yes. So there’s a, an extra bit at the back.
James: Yes.
Jacinta: You’ve got like an extra hand at the end of your elbow.
James: Yes. If you watch Japanese animation, there are a couple of animation that has, I don’t recommend it it’s a violent, an animation. They have a sword that points, it’s like a hook
Jacinta: uhhuh,
James: but it has a hook in the front and some small pointing backwards. So tthat is if you look it up in the dictionary, I’ll just [00:44:00] put it in Google and see a picture.
It’s called a scythe.
Jacinta: A scythe? Oh yes. S-C-Y-T-H-E. Okay.
James: So we called the morphology. We saw in the bent radio Galaxy a double site structure.
Jacinta: Oh, cool.
James: That’s where we got the name inspired. That’s the word.
Jacinta: I was wondering where that came from. Yeah, double scythe okay. So you’ve got this weird U-shaped jet thingies with a scythe
yeah, like extra point at the back of it. Okay. James, come on. You gotta, you gotta, you gotta tell us now what is this thing and what’s, what’s causing it.
James: Okay, cool. So now it’s obvious it’s not ram pressure because if it was ram pressure, you should bend your elbow backwards. Mm-Hmm. Okay. And then of course in the case of ram pressure, you get what the extra galactic people like Jacinta call W 80 means wide angle tail.
Mm-Hmm. It just means that the tail of the radio jet [00:45:00] makes a plume shape.
Jacinta: Mm-Hmm.
James: Okay. Spreads all over. With wide opening angle, this one stayed very collimated
Jacinta: okay.
James: So you can no longer explain it with ram pressure, which, which is your favorite. Um, then you have to start exploring what exactly is going on.
Mm. So, well, one thing you can think about is the presence of magnetic fields.
Jacinta: Mm-Hmm. Magnetic fields. Always the culprit.
James: Yes. Yes. And in our case, yes, we found, we used the X-ray data from XMM Newton telescope that says space telescope that can observe sources at x-ray wavelengths. And then we looked for what we call discontinuities or cold front in the X-ray distribution.
If you find a cold front, just regions where you have the densities of the X-ray photons to be different from the density profile of the rest of the environment, [00:46:00] then we call that a cold front. So what we realized from X-ray data is the point where you have the bending of the jet, there is a very strong magnetic field, which is a cold front detected at X-ray wavelength.
Which means there is strong magnetic field that the jet hits perpendicular to that direction.
Jacinta: Hmm.
James: Complex.
Jacinta: That’s complex. Yes. That’s really weird.
James: You really need to see the pictures.
Jacinta: Yeah, that’s, yeah. Wow. Okay. Okay, listeners, so there will have been no breakthrough there, but we just took a pause and James showed me the simulation that he made simulating, um, these magnetic fields and the, these radio jets.
And what he thought happened, and I’m gonna try an analogy, and then James is gonna tell me whether it was ridiculous or not to try and explain this. Okay. So imagine you are camping, you’re in a tent, [00:47:00] and the roof of your tent is a dome. Okay. So it’s, it’s like curved. It’s not one of those pointy ones at the top.
It’s, it’s curved. All right. And. In the middle of the night, you stand up and you forget where you are and you’re a tall person, right? So you stand up really fast and your head hits the roof of the tent, right? Yes. And then you go, oh, and then you bend forward as your head hits the tent, right? And as you bend forward, you throw one arm out behind you.
Right. That’s kind of what’s happening. Yes. So, so you are the jet as you’re standing up, that’s you going out in the perpendicular direction where you’re meant to be going. And then the, the dome of the tent, that’s the magnetic field. That’s the direction that the magnetic field is going. It’s like this dome structure over the top of you.
Yeah. It just happens to be there. For whatever reason, as you stand up, you the jet, your head hits the magnetic field and it makes you curve forward and straight out. And then you’ve thrown your hands back to balance you. And that’s the side bit.
James: That is very fantastic. I mean,
Jacinta: yeah,
James: I could never have thought about [00:48:00] that.
Yes. That’s so good. I nailed it.
Yeah, you did. And I can just add. We know where the magnetic field come from. There is magnetic field everywhere, but in the merging process of these two clusters, you generate a sub cluster material that is traveling through the medium.
Jacinta: Okay.
James: And this will compress the magnetic field lines.
Jacinta: Okay. Wait, say that again.
James: You have sub cluster material traveling through the center of the cluster. As it move, it compresses magnetic field lines. Okay. In what we call magnetic, it’s like wrapping around the magnetic field lines through the traveling sub cluster material.
Jacinta: Gotcha. And that’s where this
James: and that compresses magnetic field and it becomes, uh, stronger.
Jacinta: Alright. Okay. Yeah. Okay, so you’ve got inside this cluster, you’ve, it’s clumpy. Yeah. As we talked about in star forming regions, star forming regions, it’s clumpy. And so you’ve got some areas that are more dense than others. And as this what we call substructure, the, the denser region, it’s traveling [00:49:00] through the rest of the cluster.
It’s kind of making the magnetic field twist around it and warp and, and kind of end up in this strengthen. Yeah. In, in this kind of. Dome shape. Yes. And that’s why there’s this curvy magnetic field. And then when this innocent little radio galaxy just happens to send its jet out in that direction, it gets curved in all these weird directions when it gets to the magnetic field.
James: So that magnetic field explains why you can still keep the electrons emitting the radio waves. Okay? Keep it very collimated. Not spread all over the place, not spreading out. If the magnetic field lines were not strong enough, you cannot keep that electrons collimated. They will fly everywhere and you’ll have what you typically call wide angle tail galaxy.
Jacinta: Right. Okay. So it hits the magnetic field and the mag magnetic field lines say, come along this way. Yes. Electrons we’re going in this direction. All of us in a nice line. Yes. Everyone hold your hand of your partner. We’re going this direction. Don’t get lost.
Exactly. Okay, cool. I love it. Yeah. All right, James. Look, we’ve talked for ages and ages. That was so [00:50:00] exciting. Um, thank you so much for all of your time. This has been really awesome.
James: Yeah, it’s, it’s always nice talking to you.
Jacinta: Alright, so do you have any final messages for listeners before we go?
James: This is the best. time to be an astronomer for the young people who may be listening to this. Trust me, I am jealous of all of you because if we could do this sort of science we’re able to do with the current instruments and knowing the sort of instruments coming up in the next decade, I am super, super jealous of you guys.
It is an opportunity you should take. Take it away, run with it. There are bursaries available to study astronomy. Take your studies seriously. For those in high school, please try and do maths, physics and yeah, and chemistry. Do a bit of computer science and I look forward to seeing you guys. Um, yeah, sometime in astronomy.
Jacinta: Oh, that’s awesome. Thank you so much, James, once again, and congratulations for everything.
James: Yeah, thanks a lot.
Jacinta: [00:51:00] Bye.
James: Bye.
Tshia: Oh, that was such a great interview. I really enjoyed it. I learned so much.
Dan: You were right. Uh, you did go into a lot of detail.
Jacinta: Yeah. But it was interesting, right?
Dan: It was interesting. And I mean also I think to start with, just to hear about James and his story, uh, where he’s come from. I think that all of our minds were completely blown to hear that he did his PhD in Japanese in Japan.
Jacinta: Oh, his, his Viva and he lectures in astrophysics in Japanese.
Tshia: What
Dan: That’s wild
Tshia: and I was just. Thinking about the two of you, like if you could teach astronomy in any other language than English, what would it be?
Dan: What I would wanna teach in? Or what I could teach in?
Tshia: Okay. Let’s do both. What could you teach in and what you would like to teach in?
Jacinta: Oh, I’ll do the, what? I can teach in nothing. I, I’m embarrassingly monolingual.
Dan: I mean, I’m basically monolingual too. I think that my, my best second language would probably be Spanish, and then, I mean, I did [00:52:00] Afrikaans and Zulu at school, but, you know, I don’t think I could even begin to stand up in front of a crowd.
Jacinta: I have, I’ve tried to explain my work in Croatian. I used to live in Croatia. Yeah. Yeah. I can confirm it is extraordinarily difficult. Like hats off to
James. I I have no idea how he could do that. That’s wild. That’s amazing.
Tshia: Yeah, I thought that was really fascinating that he could do that. And it’s just one of those things when learning the science and learning the language just come together again, which is similar to what we heard from Zara as well when she came into South Africa.
Jacinta: Yeah, yeah, yeah. True. ’cause yeah, she knew Malagasy and, and French and now she like teaches in English. English. Yeah. What about you, Tshia?
Tshia: Well, I, oh gosh, I’m not monolingual. Um. But I could probably try to teach in Setswana. I think I can give explanations in Setswana mm
Dan: analogies,
Tshia: but I always have to actually understand what it is first in English and then try to bring it [00:53:00] there.
And only now I’m actually learning other words in Setswana that I didn’t know because I grew up in Soweto. Mm. But my grandmother is from the Northwest, so sometimes I ask her about these things and she just has a different language, like a different word for something I grew up. With knowing, but now I see why that would, would make sense, especially in the context of astronomy or explaining stars and galaxies and things like that.
So I think Setswana I take Setswana so the other thing about the analogies and the deep dive explanations showed that actually Jacinta is such a great teacher.
Jacinta: Aw, thank you.
Tshia: So, you know, do not necessarily say, oh, I just know a little bit, but, you know, just through your explanations. We could also get to see how much you understand your stuff.
So I think that was also cutes to just into this episode because well done.
Jacinta: Oh, thank you. I did not expect that. No. Do you like my tent analogy?
Dan: I did, I did. Thank, yeah, thank you. Jacinta I think you did a great job with that interview. Um, I,
Jacinta: I liked the, no, I liked the analogy because [00:54:00] when I was listening back to this chat with James, I actually, we had this chat quite a long time ago and I’d forgotten what it was about and when he was explaining the c shaped radio galaxy and, and like the little extension out the back Mm-Hmm.
I was like. I can’t picture what he’s talking about. And I didn’t remember doing the analogy and then it came up to that bit and I was like, oh, that makes sense. Now I can picture it.
Dan: So he came up with the same thing twice.
Jacinta: Yep. And also I had completely forgotten that James did his PhD in Japan. And then when it came, when he said that, when I re-listened to the recording and he said that, I was like, oh, really?
And then. Me on the recording said, oh really? Oh wow.
Dan: Your neural networks quite directly.
Jacinta: Who knew? I’m very similar to myself. Anyway, so yeah, I thought that was a really interesting episode. Lots of new physics that we haven’t talked about before and, but we have talked about something similar with, um, Sthabile Kolwa in episode 63.
I think it was talking about, you know, formation of stars and also [00:55:00] radio galaxies and, you know, all of these kind of chemical changes going on with molecules and vibrating molecules and all that sort of stuff. Yeah. I guess that’s the end of the science bit for today. So how are you, Dan?
Dan: Pretty good, thanks.
I am doing my big ultra marathon, which you guys kindly put on the, on the website as my hobby. Um,
Jacinta: yeah, we’ve been updating the about us page on the, on the website. Thanks, Shamin for, uh, he’s the one who’s been leading that and, uh, we needed some more spice, so I added in our hobbies.
Dan: Oh.
So
that’s my spice for the weekend.
Jacinta: When is it? It’s coming up this weekend, right?
Dan: Coming up this weekend. At time of recording. Yeah.
Jacinta: Are you ready?
Dan: I’ve gotta be. Hey.
Jacinta: Yeah.
Dan: Um,
Jacinta: how, how intensive is the training for this ultra marathon?
Dan: Uh, pretty intense. I’ve been a pretty grumpy and hungry and tired person for the last six to eight weeks.
Jacinta: Wow.
Dan: Uh, but I’m emerging from that now. And now I’m friendly and happy again.
Jacinta: Wow. You still off coffee?
Dan: I am off coffee. This is a problem. Yeah. Yes. A few more days of being off [00:56:00] coffee and then I’ll be back on it hard. Um, we, we don’t, we don’t wanna get into like the science of sport here, but basically just trying to maximize my caffeine kick on Sunday morning.
Tshia: Mm-Hmm mm-Hmm. We’ll be cheering for you. I’ll watch on tv.
Dan: Oh, thank you. Yes. I think we have mentioned it before, that this is a bit of a big deal in South Africa.
Jacinta: No big deal, but it’s massive.
Dan: Everybody stops and watches. Yeah. Watches everyone run from like city to city on a Sunday morning.
Jacinta: Yeah. Yeah.
Unfortunately, it’s, it’s before my waking time.
Dan: It’s the whole day Jacinta so it takes up to 12 hours.
Jacinta: No, but Dan, I’m sure you’re very fast and you’re going to be, you know, up ahead and I’ll have only just woken up and you’ll have already passed. The cameras.
Tshia: I’ll take five hours.
Jacinta: Just to remind the listeners how, how long is an ultra marathon?
Dan: Uh, this one’s 87,
Jacinta: 87 kilometers. I don’t even know if that’s possible, but good luck.
Dan: Oh, you can watch on TV and then you’ll understand.
Jacinta: Yeah, that’s true.
Dan: I’m joking. Who’s next?
Jacinta: Tshiamiso.
Tshia: I’m next.
Jacinta: How are you?
Tshia: I’m good. I [00:57:00] think today, I’m really good today because yesterday was such a good day for me, like ticked off things on my to-do list.
Dan: Ooh, what does that even feel like?
Jacinta: I don’t remember. So good. Oh my God.
Tshia: So I feel like now I’m finally, again, just at a right place, like where I can now do stuff as they come. So that’s really great. And then, yeah, that’s just it. Like, I’m good, I’m okay. Nice. No complaints.
Dan: Awesome. What a place to be.
Jacinta: Very nice.
Yeah. Yeah. Enjoy it for the week,
Dan: the day even. Who knows? Who knows what tomorrow holds.
Jacinta: Enjoy the moment. Seize it. Yeah.
Tshia: Uh, and how are you Jacinta? I’m good, thanks. Yeah, everything’s, yeah, actually for the moment, the last few days, not too crazy.
Dan: You or your life?
Jacinta: Both.
Dan: Okay.
Jacinta: More. More the latter than anything.
I had a little adoption party for my dog, Sam, on the weekend. Nice. [00:58:00] Sort of also to raise money for the local dog shelter where he came from. Wolf Project, Oscar’s Ark. So if you’d like to donate, maybe we’ll put a little link on our website and it was really great. We had it in a dog park. Sam had a great time running around with all the dogs and there was lots of human friends as well who were playing with him and giving him treats and everything.
So yeah, it was a lot of fun. And what have I been doing? Science-wise? Ooh. Actually I have been doing science. I,
Dan: it’s a shocking day to today.
Jacinta: I know
you would like, yeah, you would think it wouldn’t be so shocking since it is my full-time job. However, yes, I’ve been sitting with my students and actually doing science work with them and it’s very exciting, reminding me.
Yeah. I love my job and we are almost ready to publish a paper. One of my students is ready to submit in about a week, hopefully or two. And yeah, so, and
Dan: as result, should we speak to them on the Cosmic Savannah?
Jacinta: We should, yeah. Oh, we will. In fact, in July we will do an episode on that. And I’m just preparing because shortly I’m gonna be going to the [00:59:00] UK for a month mostly for work and taking my whole research group with me, so that’s exciting.
Yeah. Looking forward to that. And we’ll, um, record some episodes from there.
Dan: School tour.
Tshia: That’s cool.
Jacinta: Yeah, so sort of
awesome. Okay. Okay. And, uh, I guess that’s it for today. So thanks very much for listening and we hope you’ll join us again for the next episode of the Cosmic Savannah.
Tshia: You can visit our website, thecosmicsavanna.com. We will have the transcript, links, pictures, and other stuff related to today’s episode.
Dan: You can follow us on X, Facebook and Instagram @cosmicsavannah. That’s Savannah spelled S-A-V-A-N-N-A-H. You can also find us on YouTube where audio only episodes are uploaded with closed captions, which can be auto translated into many different languages, including Afrikaans, isiXhosa and isiZulu., I Dunno About Setswana. We should work on that.
Jacinta: Special thanks today to Professor James Chibueze for speaking with us. Thanks to our podcast manager, Francois Campher our social media manager, Sumari Hatting, [01:00:00] and our audio editor Jacob Fine.
Tshia: Also to Mark Wahlnut for music production,
Mija Wojcik and Brian Masamula for photography. Kyle Jones for Astro Photography. Suzy Carris for graphic design.
Thanks to Emil Meintjies for video creation and Moses Makungo and Abigail Thambiran for transcription,
Dan: we gratefully acknowledge support from the South African National Research Foundation, the Square Kilometer Array Observatory, the South African Agency for Science and Technology Advancement, the South African Astronomical Observatory and the University of Cape Towns Astronomy Department.
Jacinta: You can subscribe on Apple Podcasts, Spotify, or wherever you get your podcasts, and we’d really appreciate it if you could rate and review us and recommend us to a
Tshia: friend.
Dan: Yeah.
Jacinta: Cool. Could you give us an example of maybe like the tent analogy in Setswana?
Tshia: No, you put me in the spot.
Dan: No, it’s a lot of pressure. Yeah, [01:01:00] we won’t do that to you.
Tshia: Thank you. I just thank you, Dan, because Jacinta did that to me.
Dan: I won’t do that to you.
Thank you.
