Episode 26: Beyond 200 years of astronomy in South Africa

with Assoc Prof Vanessa McBride

Welcome to Season 3 of The Cosmic Savannah!

This week we recap our adventures over the break including the conclusion of The Cosmic Savannah podcasting boot camp and the run up to the 200th anniversary celebrations of the South African Astronomical Observatory (SAAO). Dan explains how you can get involved in the big celebrations! (See links below)

We are also joined by Assoc Prof Vanessa McBride, who describes her dizzying array of roles! These include astronomer at the Office of Astronomy for Development (OAD), Head of Research at the SAAO, and lecturer and research supervisor at the University of Cape Town. Vanessa is also heading the organization of the 2024 International Astronomical Union (IAU) General Assembly – the very first time this will be hosted by the African continent!

Vanessa explains her own research in the field of compact binary stars, reminding us of the wealth of astronomy and astronomical facilities right here in South Africa.

We also discuss the objectives of the OAD, acknowledging South Africa’s difficult past, in striving for an equal and inclusive future for all, in astronomy and beyond.

Featured Guest

Assoc Prof Vanessa McBride

Featured Image

A view from the front of the Main Building at the South African Astronomical Observatory in Cape Town. This view stretches back 200 years to 20 October 1820 when the observatory was first used for astronomy.

SAAO all events: saao.ac.za

SAAO 200th Anniversary Symposium: saao200.saao.ac.za

Office of Astronomy for Development (OAD): http://www.astro4dev.org/

African Astronomical Society: https://www.africanastronomicalsociety.org

Zooniverse: https://www.zooniverse.org/

Acknowledgements

Show notes prepared by Andy Firth. Transcript by Sumari Hattingh.

Transcript

Dan: [00:00:00] Welcome to The Cosmic Savannah with Dr. Daniel Cunnama.

Jacinta: [00:00:08] And Dr. Jacinta Delhaize. Each episode, we’ll be giving you a behind the scenes look at world-class astronomy and astrophysics happening under African skies.

Dan: [00:00:16] Let us introduce you to the people involved, the technology we use, the exciting work we do, and the fascinating discoveries we make.

Jacinta: [00:00:24] Sit back and relax as we take you on a Safari through the skies.

Dan: [00:00:33] Welcome to what we think is episode 26.

Jacinta: [00:00:36] Season three, episode one.

Dan: [00:00:38] That’s our debate.

Jacinta: [00:00:38] We disagree on how we’re going to number these.

Dan: [00:00:41] So whatever it’s numbered on whatever app you’re using, that’s what the number is.

Jacinta: [00:00:46] And who won. Welcome to season three, everybody!

Dan: [00:00:51] Welcome back. We have had a long break. Some of it Covid induced, some of it business induced on both of our parts. We’ve been lucky not to have Covid.

Jacinta: [00:01:03] Both of us have been very lucky.

Dan: [00:01:04] We hope you have been too.

Jacinta: [00:01:07] Yes, we hope everyone’s safe for our returning listeners. Welcome back. And for our new listeners, a warm welcome to The Cosmic Savannah family. First of all, we would like to start by asking if you like this podcast episode, can you please leave us a review on iTunes and like and subscribe and tell a friend if you can, because that’s really going to help us to spread the word and get new listeners.

Dan: [00:01:35] So we should get started with a sort of brief recap of what we’ve been up to.

Jacinta: [00:01:39] Yeah. Well, I guess why don’t we stop for our new listeners, reminding people who we are? Who are you, Dan?

Dan: [00:01:44] My name is Daniel and I am the science engagement astronomer at the South African Astronomical Observatory, which is based here in Cape town. And our observing site is up in Sutherland in the Northern Cape about 400 kilometers away. So that’s a dark site at high altitude. My role here at the observatory is science engagement. So promoting our research, promoting our facilities and reaching out to the public and stakeholders and trying to raise awareness of astronomy.

Jacinta: [00:02:14] You’re a reformed research astronomer.

Dan: [00:02:17] Well, there’s still…

Jacinta: [00:02:18] You’re still keeping your finger in the pot – now what’s the expression? Keeping your finger in the pot?

Dan: [00:02:26] Foot in the door? I don’t know.

Jacinta: [00:02:27] Yeah, foot in the door. That’s where I was going.

Dan: [00:02:29] I think that we’ll talk about it a little bit more now, but I’ve been very busy the last couple of years, and haven’t had a chance to do much research, but it’s certainly something that still appeals to me. And, yeah, I’d like to get back into it. Once all this is done. And yourself?

Jacinta: [00:02:47] Great. I am Jacinta.  I’m a research astronomer at the University of Cape town, UCT, and I’m a postdoctoral research fellow and I study galaxies; galaxy evolution – how galaxies have changed over the history of the universe. And I mostly use radio telescopes such as MeerKAT, which is South Africa’s incredibly powerful radio telescope in the Karoo. It’s one of the most powerful radio telescopes in the world and it’s run and organized by the SARAO – the South African Radio Astronomy Observatory. I actually have a SARAO fellowship and I’m from Australia, but I moved to South Africa about two years ago. That’s when we decided to start this podcast. Why did we start this podcast?

Dan: [00:03:33] I asked myself that every day. No, I mean I think we realized pretty quickly that there wasn’t enough promotion of African astronomy. There’s so much going on in this country. We’ll talk about it a bit more with our guests today, but there really is a lot to be proud of – a lot going on. That’s something which we want to share with the South African public and also the rest of the world.

Jacinta: [00:03:58] Yeah, exactly. It’s such a vibrant place to be and there’s…my blanket fort is falling down.

Dan: [00:04:07] So we’re once again doing blanket fort recording because our regular studio does not abide by Covid regulations because it’s probably only about a meter across. We can’t distance ourselves at all in there.

Jacinta: [00:04:24] No, so we’re sitting – socially distance – under blankets at the moment on the floor. Anyway, what was I talking about? Vibrancy of the South African astronomy environment. Yes. Okay. Well, yeah, that’s why I’m here. I think that it’s important that we can make this accessible to everybody, not just scientists and astronomers, but absolutely everybody because it’s super exciting what’s happening here and it’s super important as well – as we’re going to hear today with our guest, Professor Vanessa McBride.

So Vanessa is going to tell us all about the work that she does as the Head of Research for the SAAO and also her role as astronomer for the Office of Astronomy for Development – the OAD – which tries to leverage astronomy in order to help achieve the UN’s sustainable development goals, which was really fascinating to talk to Vanessa about.

Dan: [00:05:19] So before we get into that, maybe we should talk a little bit about what we’ve been up to in the break?

Jacinta: [00:05:24] Yeah. Good idea.

Dan: [00:05:25] What have you been up to?

Jacinta: [00:05:27] Several things. So, first of all, I have finished a research paper.

Dan: [00:05:31] Congratulations.

Jacinta: [00:05:32] Thank you. Yeah, for those who don’t know, that’s what we get paid to do. That’s what I get paid to do, is unique research and then publish it in an international journal. So I have finished a research paper, which uses the MeerKAT telescope. We’ve got some data as part of the big international collaboration and I am looking at giant radio galaxies and we found some pretty cool things, but I can’t actually tell you the results yet until it’s been accepted for publication.

So watch this space and I will be able to tell you all about it soon. The other thing I’ve been doing is running the podcasting boot camp for our wonderful Cosmic Savannah trainees. You and I, Dan, have been running this training boot camp where we’ve taught them everything from interviewing a guest to doing their own editing and creating the entire episode, publishing it, writing their show notes and social media. And we’re very, very proud of all of our boot camp graduates and you’ll have seen the results of their hard work in the mini episodes that we published during the break of the formal seasons of The Cosmic Savannah.

Dan: [00:06:41] Yeah. I mean, I think that it was a great experience for us take stock of what we’ve learned and try and share that with some younger astronomers who are excited to share their work. And I think that we’ll definitely chat more to them in the future and see what they’ve been up to.

Jacinta: [00:06:55] We’re hoping to incorporate them as regular contributors to the podcast. All right. Dan, what have you been up to?

Dan: [00:07:01] Whew, a lot. We’ll talk a little bit about it with Vanessa, but next week, when this comes out, but next week in reality too, will be the 200th anniversary of the SAAO. And that’s a that’s a big moment. I think that it’s a good time to take stock of where we’ve come from. South Africa has had a long and tumultuous history. The observatory had been operating for 200 years through all of that. It’s gone through many changes. It’s weathered many storms and produced excellent research throughout that time. I think it’s a great opportunity to look back at that but then, as we’ve been saying, it’s an excellent opportunity to look at the last couple of decades and the future, because 200 years of the astronomy in South Africa is truly world class. It’s an incredibly exciting place to be. And what’s coming in the next couple of decades is really going to be mind-blowing. So it’s a sort of nice moment to take stock. And look forward. And I think that we’ve been making a big effort – and I’ve been leading a lot of those efforts – to make a bit of a splash. So we’ll be holding various events next week to try and raise the profile of astronomy and the observatory.

Jacinta: [00:08:21] Tell us more about these events that you’ve been organizing, what events are being held for professionals and also for the public and how can people get involved and where can they find more information?

Dan: [00:08:32] There are various things underway. The first and probably biggest thing is the unveiling of the SAAO as a National Heritage Site. So in South Africa, much like you have World Heritage Sites around the world, we have National Heritage Sites recognizing the significance of a site and its cultural and heritage significance to the country. And then at the end of 2018, the SAAO was declared as a National Heritage Site and recognizing the scientific contributions over the years and that’s significance to the country and we will be unveiling this site as an official National Heritage Site on Tuesday, the 20th of October, which is 200 years to the day from the establishment of the observatory. So a big event on a big day. And we will have addresses by the Minister of Science and Innovation, the Minister of Arts and Culture and various others. We’ll be unveiling the plaque of the National Heritage Site.

Jacinta: [00:09:27] Wonderful. And how can people watch that?

Dan: [00:09:28] So it will be streamed online obviously for Covid regulations, we had planned a large in person event, but as such, we cannot proceed with that. So it will be a large online event. You will be able to link through from our website, otherwise follow the observatory on social media. We can post all those links in the show notes, but if you just go to saao.ac.za, you’ll be able to get all the information you need. Other events going on – we have a large Astronomy Symposium happening that week, which kicks off on the Tuesday and runs through to Friday. We’ve got talks from astronomers all over Africa, and we will be talking about the exciting astronomy going on. We’ll talk about the history, we’ll be talking about astronomy going on across Africa, we’ll be talking about the social impact of astronomy and the indigenous knowledge and really covering a lot of topics and we’re trying to keep it quite general and inclusive. And in that vein, it is open to all. So if any interested astronomers or, you know, amateur astronomers or anyone just interested in astronomy and what’s going on here, you’re welcome to join. That website is saao200.saao.ac.za, but basically you just go to our website and you’ll find links to everything. So yeah, that’ll be a very exciting three-and-a-half day program and anyone is welcome to join and see what we’re doing. It’ll be streamed online again, all fully virtual. It should be very exciting.

Jacinta: [00:10:53] Yeah. I’m really excited about that. So you and I will be chairing a couple of the sessions. So looking forward to hearing the contributions of everyone in that and any other events for the public?

Dan: [00:11:07] Obviously the public is of huge importance to us. And the original plan was to have a large astronomy festival this week. And obviously that can’t go ahead. We can’t have thousands of people in one space. So we have tried as much as possible to run a virtual program. And we’ve already had a couple of events: virtual storytelling we will have a series of lectures through the week, which will happen in the evenings with time for questions and the answers from the public. Those will be on our Facebook page and also streamed online on YouTube. So we encourage the public to get involved in those. We also have an astrophotography competition at every level. So you’re welcome to submit sketches or drawings or paintings, or as well as, you know, some high end astrophotography, if that’s what you’re into. And then on the last evening of the virtual festival, we will be having a virtual star party. So we all have some live stargazing, which will be streamed live. And that’ll be interspersed with music from Master Kg – who is famous in South Africa and probably in other places around the world for his recent hit Jerusalema. Our South African president even mentioned and got encouraged at the nation to get involved in doing this dance, which…

Jacinta: [00:12:17] Really? I missed that entire thing.

Dan: [00:12:20] In one of his presidential addresses, he sort of got everyone trying to do the dance. We are gonna get involved in and do our best.  I haven’t learned the dance yet.

Jacinta: [00:12:35] Well, I’ve been watching you dance around your office today. What’s your song?

Dan: [00:12:40] Well, so I’ve been dealing with an incredible…

Jacinta: [00:12:44] Little bit of stress?

Dan: [00:12:45] I’ve been dealing with it a little bit of stress. I’ve been taking a leaf out of The Beach Boys’ book and dreaming of Kokomo. Okay.

Jacinta: [00:12:56] Come on, run off a few lines for us.

Dan: [00:12:58] Aruba, Jamaica, ooh I wanna take ya’ to Bermuda, Bahama, come on pretty mama

Jacinta: [00:13:07] Okay, well, thank you.

Dan: [00:13:11] I’m sorry. I was just getting back.

Jacinta: [00:13:14] You were inspired by Space Force. If anyone’s seen that on Netflix.

Dan: [00:13:19] Steve Carell. Wonderful. Anyway, we should really get to work.

Jacinta: [00:13:22] We really should. Okay. Now, well, should we hear from Vanessa?

Dan: [00:13:26] Absolutely.

Jacinta: [00:13:26] All right. Let’s hear from Vanessa about the OAD – her role as Head of Research at the SAAO and several other hats that she wears, she kind of just does everything.

Dan: [00:13:36] She sure does.

Jacinta: [00:13:37] All right. Let’s hear from Vanessa.

Dan: [00:13:40] So today we’re joined by Vanessa McBride, who is based at the Office of Astronomy for Development here at the South African Astronomical Observatory. And she’ll be talking to us a little bit about what she does. Vanessa, welcome to The Cosmic Savannah.

Vanessa McBride: [00:13:58] Hi Dan. Hi, Jacinta. And nice to be here.

Jacinta: [00:14:01] Thanks very much for joining us.

Dan: [00:14:04] So Vanessa, perhaps you can just explain to us some of your wide and varied roles, with the Office of Astronomy for Development, but also for the observatory.

Vanessa McBride: [00:14:12] I’m an astronomer at the Office of Astronomy for Development. It’s one of the offices of the International Astronomical Union, which is based in Cape Town and hosted at the South African Astronomical Observatory.

I’m, also fulfilling the role of Head of Research at the South African Astronomical Observatory. And that’s a role that allows me to try to work with other astronomers, to create an environment that’s really conducive to research at the observatory. And I also have an adjunct associate professorship at the University of Cape Town where I participate in some teaching and joint research projects at postgraduate level.

 Dan: [00:14:54] You’re right, hey, wide and various. I’m not sure where you find the time. Perhaps we should start with just talking a little bit about the Office of Astronomy for Development and what exactly, the objectives of the office are for the International Astronomical Union, also, locally. 

Vanessa McBride: [00:15:14] Okay. Well the office has been established in 2011 and really it grew out of the idea that, you know, the skills, the methods, the techniques we use, in astronomy can really be applied more broadly than just in astronomy. And it’s also, you know, comes together with the fact that as I’m sure all of us know, astronomy is interesting to a wide variety of people, it has a philosophical context to it.

It’s also part of many different cultures. And so using all of those aspects, we try to think about ways that, astronomy can influence the sustainable development goals. So look at how social economic development can be affected in some way through astronomy.

Dan: [00:16:08] What are some of the examples of these projects? I mean, I know that in the recent months and, last year, with the Covid pandemic, there have been a lot of astronomers who’ve, lent a hand in terms of modelling and trying to predict the pandemic and analyse the data. Whether those, contributions were welcome and productive, I’m not sure, but I know that a lot of astronomers, and many that I know personally got involved in that, is this the kind of thing you’re talking about, or what are some of the other examples of projects that the office runs.

Vanessa McBride: [00:16:40] Yeah, I think that’s part of it Dan. So for example, there can be sort of fields in which you can apply techniques, for example, the models and things that have been applied through Covid, these are things that are, based in differential equations.

But of course that requires specific domain knowledge, right? Which often we don’t have as astronomers. So for that reason, one of the focuses of our office is really to work in a sort of cross-disciplinary context because, we may come as astronomers with some of the skills, but we don’t always have that domain specific knowledge that you need really to make an impact.

Like we’re not up to date with medical literature, we don’t know what things they’ve tried and failed. So, we can make contributions, but it’s also important to do it in conjunction with the experts in the field. I mean, some of the other examples of how astronomy can make an impact, are kind of embodied in the three flagship projects of the OAD at the moment.

So OAD is Office of Astronomy for Development, and at the moment we have three of these kinds of projects that have crystallized over the last 10 years through a process where anyone can apply for funding to run one of these astronomy for development projects. And those projects – the first is looking at how a socio-economic development can happen around an observatory. So that may be either through, direct economic empowerment. So for example, if you have a beautiful observatory and a dark sky site, it may not be a research observatory, but it could attract tourists, for example. And those – through tourism – generate money for the local community.

Another of our flagship projects is looking at the kind of the big picture at how, if you look at the earth from space and sort of the view that astronomy gives you, how can that kind of perspective allow us to be better global citizens? And that project is being led through the European regional office of astronomy for development.

And then the last flagship project really looks at sort of data and skills in astronomy and how those transfer to other fields. So that looks at things like machine learning, data wrangling these kinds of things that we have to do in our daily lives as astronomers. But the fact is that they’re also incredibly valuable in other economic sectors and of course, in other fields of data intensive research,

Jacinta: [00:19:28] That’s absolutely fantastic Vanessa and the work of the OAD is really, really awesome. So for our listeners, could you explain a bit more about what you mean by development and I guess many people are surprised when we say that astronomy can be used for development.  I know you’ve written a lot on that in the past. Could you say a bit more about that?

Vanessa McBride: [00:19:49] Yeah. So I think it’s captured most simply in the slogan that we use in our office: “Astronomy for a better world”. And so, by development we mean improving people’s lives in some way; whether that is improving their lives by allowing them to have better the prospects for finding jobs or whether it’s improving their lives by allowing them to make additional income through an astro-tourism initiative or whether it’s improving lives through a better quality of education or access to new educational content. All of those are ways in which development can be impacted. And at the Office of Astronomy for Development, we use the United Nations’ sustainable development goals as a very broad sort of, metric for development.

You’ve probably seen some of the lovely posters; they’re very colourful posters showing these 17 development goals that range from sort of good health and wellbeing to economic empowerment through to, quality education and partnerships for the goals. So these are what we use as our definition of development in the broadest sense.

Dan: [00:21:05] How does the office implement these projects? I mean, do you take an active role? Is it a funding role? is it an advisory role where people report to you and on their progress and   on their goals and how they’re affecting the environment they’re in? I mean, is there a process of monitoring and evaluation that’s taking place to see the effect of these sorts of interventions?

Vanessa McBride: [00:21:29] To some extent there is, Dan, so at the moment, and actually since 2013, the OAD has run an annual call for proposals that is open to anyone in the world. And it’s a call for funding.

So you can suggest an Astronomy for Development proposal, in any sort of field that you want, you don’t even need to be an astronomer or have an affiliation with a university or a research institute. And then you can have a small chunk of funding. It’s usually a few thousand euros and those projects can come from anywhere in the world and they’re usually funded for a year and there is a kind of a monitoring and evaluation process – fairly simple because of course the grants that are not so big. So we don’t want to make these things too onerous for small grants. And then with the flagship projects – how we see those developing. So those are more of a sort of top down approach where we can imagine having rather large programs with a potential for a global rollout and those will have to be funded separately. At the moment we have some funding for aspects of the flagship projects, but they’re not fully funded at the moment. So we kind of have a real mixture of grassroots projects that are designed very much by the community and then these sorts of higher level projects with the potential for outside funding.

What we also did this year – because it was such an unusual year for everyone – is we had a very rapid turnaround COVID related call for proposals. So in addition to our usual call we had a call that was an attempt to try and alleviate some of the burden on people placed by the pandemic and by the lockdown.

So we had such a variety of proposals from all over the world for this funding – so it ranged from cultivating food gardens, during lockdown to making data available for remote tutoring of students at schools and universities. So a whole range of projects, really. We’re interested in this kind of funding.

Jacinta: [00:23:41] Can you give us some examples of your favourite projects?

Vanessa McBride: [00:23:45] Yeah, of course, I have a couple of favourites, but one of them that really stands out for me, is a project that was run a couple of years ago in Sierra Leone. The point of that project was to improve literacy in school aged children. And they just were very sneaky about it because they made the topic so interesting. They used astronomy as kind of the hook to just grab the interest of these school aged children and to teach them these concepts around literacy as they were going through it. So they were kind of just learning without realizing they were learning.

So that’s one of the projects I really like. Another project that I thought was really interesting was a collaboration between a group in the UK and a group in Kenya.  And the point of this was that there are many eye conditions which don’t need to leave you with a disability if they are often treated, right. But the problem is that in lots of rural regions you don’t have access to ophthalmologists or someone who can really diagnose what’s wrong with your eyes.

This project was looking at a kind of a Zooniverse approach to diagnosing these eye conditions. So they’ve made a specially adapted camera that could go on the back of a mobile phone and you could take pictures of people’s retina with this and that was done through field workers and they would then upload these pictures onto a site for classification through crowd sourcing, right. So many different people all over the world could potentially log into a browser and then learn through a simple tutorial, how to classify various of these conditions. And that way you could get a diagnosis. So this is a project, of course, it was a trial run, but seemed to work quite well.

Dan: [00:25:36] Wow that’s very cool. So for those of you who don’t know, Zooniverse is another astronomy program where you can go online and identify different astronomical objects generally galaxies with your eyes because the human eye is still quite a lot better than the normal computing techniques. So it was sort of a crowd sourced approach to gaining some astronomy knowledge. Very cool to use it for ophthalmology.

Vanessa McBride: [00:26:02] Yeah. There’s all sorts of interesting projects on the Zooniverse now, that actually have nothing to do with astronomy.

Dan: [00:26:07] Really? I haven’t been on for a while, obviously. We’ll plug it in our show notes and send some people there. So you’re juggling this sort of Astronomy for Development, but also your own research and the research of the entire observatory?

Vanessa McBride: [00:26:25] Thankfully, I don’t have to do it single-handedly, right? I think we’re very fortunate at the observatory that we have like a really dedicated and motivated bunch of people who are doing research. And of course, in addition to all the other things, like keeping the observatory running, making sure telescopes are operational. So that part of the job is kind of easy. You just have to think about ways in which we could enable people to do the best research they can.

Dan: [00:26:56] So your role is essentially to encourage researchers and enable them to do more work. And this is – we have these facilities up in Sutherland where astronomers can use them – but we’re also a national facility and we provide telescope observing time to all of the South African researchers at universities and it also researches abroad. Does that fall under your gambit or are you primarily focused on the research of the observatory itself?

Vanessa McBride: [00:27:22] No, my primary role is really to look at research of astronomers and students here at the observatory. We know we have a huge amount of people using the telescopes and the instruments in Sutherland, but it’s very important also, that our Institute provides more than just a service, right.

We don’t just provide instruments to use, but we use them ourselves and we are doing cutting edge science with those. And it’s important that we stay at the forefront because, once you really doing the cutting edge science and you know what you need to discover the next problem, it allows you to feed that knowledge back into building a telescope or an instrument that the community can really use and that you can use to do that kind of science. So we see it as a very kind of, I don’t know, yin and yang process that you really need the good science in order to make the observatory work.

Dan: [00:28:17] Did you know, that, yesterday I looked up how many research publications the observatory has produced in its 200 year history. Anyone want to guess?

Jacinta: [00:28:39] I’ve got no idea.

Vanessa McBride: [00:28:41] What, do we produce about 80 a year?

Dan: [00:28:43] So 136 last year, but 3000 in total, over the 200 year history with over 75,000 citations.

Jacinta: [00:28:47] Gosh.

Vanessa McBride: [00:28:48] Wow.

Jacinta: [00:28:49] So, fairly productive. Yeah, that’s amazing. So that brings us to the 200th anniversary of the SAAO. Vanessa, so you’re Head of Research and you’re also involved with the OAD. Can you tell us a little bit more about your insights into the history of the observatory and its role in the community, inclusivity and where we’re moving towards the future.

Vanessa McBride: [00:29:16] Thanks Jacinta. I don’t have a huge amount of knowledge on the history of the observatory, but I do think this 200 year milestone is kind of an interesting place to be because obviously the observatory was founded as guidance for the Navy – for the Admiralty in their efforts to colonize and, expand the empire. So in a way it’s got a bit of an interesting background, but yet here we are today and we’re doing this amazing science and we’re also trying to grow this community and cohort of black astronomers, which we’re just starting to see move into these professional positions. So I think it’s very exciting time to kind of look both back at the history of the observatory – where we come from – but also to look forward because it’s a moment really to shape the future of the observatory.

Dan: [00:30:16] Yeah, I think there’s something wonderful about something so old, because it does show you how things transform. As you said, it started off as essentially a time service for the Royal Navy and very quickly, in a matter of a decade or two, transformed it to one of the global leading observatories – astronomical research observatories – in the world. We measured the first distance to a star, we did the first photographic sky survey here and then now in recent decades, we’ve transformed again into this sort of South African Observatory with SALT being the pinnacle of that – with SALT being unveiled in 2005. And since then it’s really a world class telescope – one of the largest in the world and the largest in the Southern Hemisphere. I think that looking at that journey from those beginnings to where we are now, and then imagining where we can go in the next few decades. It’s pretty amazing to me. I think it’s incredibly exciting. And as you say, it’s a wonderful opportunity to do that re-imagining and try and look at where the observatory is going to go.

Vanessa McBride: [00:31:25] Yeah, absolutely. I mean, I think it’s very exciting that, we’ve had this institution in South Africa, for all this time, doing cutting edge science and through some pretty tumultuous times. It’s I mean it’s been consolidated as the South African Observatory. It’s sort of seen through Apartheid times and now we’re really trying to work hard to undo this legacy of Apartheid that we’ve been left with. And it’s quite interesting to see how the observatory and its people are moving through these new times, because of course there’s a lot of work to be done we are still, very consumed with unlearning some of the prejudice that all of us have picked up through these times. And really building an observatory that is inclusive and welcoming to most of South Africa’s population.

 Jacinta: [00:32:21] Okay. So there’s a bit of work still to do, or a lot of work still to do, which, I’m really glad to hear that there’s people like you and your colleagues and others pushing for this. In your role as Head of Research, what sort of vision do you have for the near to medium future?

Vanessa McBride: [00:32:26] So thanks Jacinta. I think it’s fun to work on these vision questions because you know, part of the job here is really to bring together this amazing group of researchers and to inspire them with a vision that we can all get behind and move forward. If you think about the last couple of decades we’ve seen, as Dan mentioned, the Southern African Large Telescope go from an idea to an actual living telescope that is working and producing results.

We’ve also seen – in South Africa and this landscape- the MeerKAT radio telescope, which also, just was an idea. And we then won the bid for the site and we now have an incredible telescope that we’re using to produce fantastic results. So what is the next big thing on the horizon? And I think that’s where we are at the moment – we’re thinking, where do we go from here? What are the instruments, what are the techniques that we are going to use to push the big questions in astronomy going forward?

And are those big questions about new and interesting discoveries that we are going to find through the big surveys of the sky that are coming online? All these questions we want to answer about how galaxies evolve and how they form and how they give rise to the stars and planets that we know. The things that we’re battling with, not only me, but it’s the whole of the observatory at the moment, is sort of working together, putting their heads together to think about,  what is the area in which we want to lead and what will be the big thing that we do in the coming decades.

Dan: [00:34:18] Yeah for me. I mean, you say, we’re putting our heads together; where can we go from here? I feel like it’s and maybe it’s just me, but I feel like it’s so much more exciting than that. It’s like, where can’t we go from here? We have SALT. We have MeerKAT, the SKA is coming – there’s limitless opportunity in South Africa for astronomy.  We have government support, we have the Astronomy Geographic Advantage Act. We really are in a uniquely positive position in the world when it comes to growing astronomy. I think that it’s, the next 20 years for us, the opportunities are endless. And I think it’s an incredibly exciting time to be an astronomy.

Vanessa McBride: [00:35:00] I agree, Dan. I think we really do. We have a lot that we can choose from here. And I think part of the value that we have here in South Africa, is also that we recognize, by hosting the OAD and by the work that the observatory does in the collateral benefits around SALT in the schools’ program, we realized that, whilst we do niche research about these kinds of topics, we also realize that a lot of the techniques, the methods, and in fact, the inspiration of astronomy really has to be available to a larger part of the population. We have to use this to inspire students, to study science. You know, we have to use these techniques to think of ways of lifting people out of poverty, because at the end of the day, we are in a country where we are facing these challenges of poverty, and unemployment.

Dan: [00:35:55] I mean I think you’re right. How can we use this advantage to further the socio-economic development of our country? It’s clear we are at a huge advantage in terms of astronomy right now and it’s an incredibly powerful position to be in and we need to make sure that we optimize that so that our citizens – the South Africans and Africans – gain the maximum benefit from it. Because at the end of the day, it’s our astronomy, which we are doing here in Africa and we need a full buy-in and full inclusivity of our citizens, in that endeavour.

Vanessa McBride: [00:36:34] I agree. And I think one of the ways I like to say that it’s – as astronomers – we sometimes have our heads in the stars, but we really do need to have our feet firmly planted on the ground.

Jacinta: [00:36:45] Absolutely.   And it’s a privilege to study astronomy and it’s so fascinating and exciting. I think we do owe it to society of course to share this passion and the insights, and with all of the other benefits that we’ll bring and especially if it can help in the areas of development. Just before we end, Vanessa, you mentioned that you also work at UCT – the University of Cape Town – and you do your own research and you have your own students. So can you mention a little bit about that and what you work on?

Vanessa McBride: [00:37:18] I do supervise some students. Actually, I have one master’s student who’s just writing up now. I have no PhD students – one of them has just submitted and received her PhD this year.   But, my field of interest is these binary stars that are transferring mass from a really massive star- much bigger than the sun – onto what we call a compact object or a neutron star and that’s the remnants of a star; after it has exhausted its fuel. Just the core remains as a very dense object called a neutron star.  I study these kinds of objects in our neighbouring galaxies – you may have seen them in the sky; the large and small Magellanic clouds – and they’re interesting objects because they trace star formation and you can see these things out to pretty large distances. Some of the stuff I’ve been working on recently is really trying to trace how – being in a binary, like this, these two stars where they’re transferring mass from one to the other – actually changes the evolutionary pathway of these stars.

So it means that they go through different phases than they would have if they were just isolated and sort of burning fuel on their own. So my work involves mostly observations in the optical, some observations in X-ray and more recently we’ve done some observations in the radio to try and connect the dots of these objects at different phases in their lives to really see how they evolve as a group.

Jacinta: [00:38:52] So have you been using SALT or MeerKAT for this work?

Vanessa McBride: [00:38:55] Yes, we have. We’ve had some MeerKAT observations last year, which we’re still analysing. And we also use SALT on a regular basis. It allows us to measure how far away these objects all from each other, how big their orbits are, and actually helps us to try and understand some of the process of this transferring of mass from one component, one of the stars onto the other.

Jacinta: [00:39:20] That’s so cool.  SALT and MeerKAT are just amazing and all of the work from the observatory also SARAO – the South African Radio Astronomy Observatory. I’ve been quite silent during this discussion because all of the excitement of South African astronomy is making me question my future and I just never really want to leave. This is just really the best place to be an astronomer right now. So yeah, exciting times.

Vanessa McBride: [00:39:44] Yeah, exciting times and lots to come.

Dan: [00:39:46] Speaking of lots to come, there was one other role, Vanessa, which you have not mentioned, which I will mention. That is, you are leading the organization of the IAU general assembly in 2024, which will be held here in Cape Town. Do you want to talk to us a little bit about that?

Vanessa McBride: [00:40:03] Yeah, that’s a super exciting event on our calendar, right. Even though it’s four years away.  So the International Astronomical Union has been around for about a hundred years and they have a general assembly – so a big meeting every three years – one of my colleagues describes it as the World Cup of astronomy.

This meeting has been to many places on the globe but it has never yet been held on the continent of Africa. So we were thrilled to win the bid to host this meeting in 2024. The meeting will be held in Cape Town, but it really is an African meeting because it’s the first time it will be held in Africa.

Whilst it’s exciting to have the meeting here in Cape Town, it’s also a fantastic opportunity that we can use to work towards some of the collaborations and how we want the astronomy community across Africa to evolve as we work towards this meeting in 2024. So you may have heard recently, that the African Astronomical Society has been re-established with a new vigour and they are really doing some incredible work in pulling the community of astronomers together, on the African continent. For now, it’s a small community, but it’s really been growing very rapidly. We’re very excited to see Africa represented in the global astronomy endeavour in this way.

Dan: [00:41:35] It’s very exciting, I mean, four years away as if somebody who’s just been organizing all this stuff for next week, four years is very, very close.

Jacinta: [00:41:48] Well, we may as well end it here and let you both get on with your organization of your multiple roles.  Good luck for the 200th anniversary celebrations and we look forward to talking to you again soon, Vanessa.

Vanessa McBride: [00:42:01] Lovely chatting to you, Jacinta and Dan.

Dan: [00:42:04] And you, Vanessa. Thanks for joining us.

Jacinta: [00:42:04] Bye. 

Jacinta: [00:42:06] Dan, I was having a bit of, as I said, a bit of an existential crisis while I was listening to you and Vanessa speak during that interview, which of course we did on Zoom, which was the reason for the slightly poor audio quality. But, you’re right. It’s just so exciting here in South Africa. My contract’s only for another year and I have to decide, you know, where in the world I want to go after that, but astronomy here is so good.

Dan: [00:42:41] Yeah. I mean, it really is. I think that we are in a golden era here in South Africa for astronomy. And I think that there’s going to be some major discoveries coming out of this country, which is the goal of astronomy research at the end of the day. But I’m very excited for the all South Africans.

Jacinta: [00:43:00] Slight sidestep. Speaking of recent, amazing astronomical discoveries. Life on Venus?

Dan: [00:43:06] Well, no, you know, some new molecules on Venus, which we don’t have a non-biological explanation for.

Jacinta: [00:43:12] I mean, I’m not saying it’s aliens, but… no, I thought that was really cool. I watched that press release and there’s been some absorption patterns in the light coming from Venus. And that could either be some chemical process that we’ve never observed on the earth or being able to reproduce on the earth, or it could be from some sort of bacteria, microbial life in the atmosphere of Venus, which we haven’t, we’re not saying it’s aliens, but it’s a tantalizing signal.

Dan: [00:43:48] Yeah, and I think it’s good to look the other way for a change. Everyone always looks at Mars. I think the advantage of Mars is, despite it being hostile and whatever, it’s not quite as hostile as Venus.

Jacinta: [00:43:59] Yeah. It doesn’t have sulfuric acid rain, for example.

Dan: [00:44:06] We have the feeling we could make Mars livable, but Venus is like the end point of our climate change disaster.

Jacinta: [00:44:15] Well it’s the runaway greenhouse effect, so let’s avoid that. Anyway, I think that’s pretty much it for today. Dan, did you want to give us any final plugs?

Dan: [00:44:24] Yeah, just a reminder, if you are interested in getting involved in the 200 year celebrations or watching the unveiling or anything, check out our website. Otherwise follow the observatory on social media and we’ll obviously share the links on The Cosmic Savannah social media too.

Jacinta: [00:44:39] Alrighty. So that’s the end of season three episode, one.

Dan: [00:44:43] Episode 27…

Jacinta: [00:44:46] of The Cosmic Savannah. Thank you very much for listening and we hope you’ll join us again for the next episode.

Dan: [00:44:52] You can visit our website thecosmicsavannah.com. We will have the transcript links and other stuff related to today’s episode. You can follow us on Twitter, Facebook, and Instagram @cosmicsavannah. That’s Savannah, spelled S-A-V-A-N-N-A-H.

Jacinta: [00:45:06] Special thanks today to associate Professor Vanessa McBride for speaking with us.

Dan: [00:45:11] Thanks to Sumari Hattingh for social media and transcription assistance.

Jacinta: [00:45:14] Also to Mark Allnut for music production, Janus Brink and Michal Lyczek how for photography and Lana Ceraj for graphic design.

Dan: [00:45:22] We greatfully acknowledge support from the South African National Research Foundation, the South African Astronomical Observatory and the University of Cape Town – Astronomy Department – to help keep the podcast running.

Jacinta: [00:45:31] You can subscribe on Apple podcasts, Spotify, or wherever you get your podcasts. And if you’d like to help us out, please rate and review us and recommend us to a friend.

Dan: [00:45:40] And we’ll speak to you next time on The Cosmic Savannah.

[End music]

Dan: Aruba, Jamaica, ooh I wanna take ya’ to Bermuda, Bahama, come on pretty mama.

Mini Episode: Capturing the whispers of hydrogen

With Andrew Firth

Hosted by: Tshiamiso Makwela

In this mini episode, we chat to Andrew “Andy” Firth, a Masters students at the South African Astronomical Observatory and the University of Cape Town.

Andrew tries to detect the faint signals of hydrogen gas in distant galaxies using a new technique. He does this through stacking data cubes of these galaxies. This clever new technique will be applied to some of the MeerKAT radio telescope data.

Growing up in the Karoo, Andrew had the pleasure of experiencing the beautiful Southern night sky. With this experience, Andy not only fell in love with the stars from afar, but also believes that astronomy is one of the avenues of understanding the universe and our origins at large.

This week’s guest

Featured image

This image shows one of the most detailed images ever produced of hydrogen gas in a spiral galaxy (other than our own Milky Way). This galaxy is called M33. The colour shows the Doppler redshift and blueshift (direction of movement) of the gas.
Image credit: https://public.nrao.edu/gallery/

Related links
Link: https://www.cv.nrao.edu/course/astr534/HILine.html
Link: https://www.nrao.edu/pr/2001/m33gas/index-p.shtml

This episode is hosted and produced by Tshiamiso Makwela

Episode Transcript

Tshiamiso: [00:00:00] Hello, and welcome to another mini episode of the Cosmic Savannah. My name is Tshiamiso Makwela your guest host for today’s mini episode. I’m currently a PhD candidate in the department of astronomy at the University of Cape Town. My work looks at the astronomy education research field, where I aim to probe student engagement with different aspects of astronomy.

But today it isn’t about me. My guest today is Andrew Firth, Andrew is a master student at the university of Cape town and the South African astronomy observatory. He is currently working on his research on the improvement of radio data, which will be applied on some of the surveys of the MeerKAT Telescope you heard, right? The MeerKAT Telescope.

In this interview, Andrew will be sharing how he developed an interest in astronomy and the role that he’s father played in this. His research, is in HI astronomy, which is the 21 centimeter spectral line, which is created by changing energy states of neutral atoms. He is specifically looking at improving SNR through cube sticking.

So you might ask what is SNR? So SNR refers to signal to noise ratio. So he is doing cube stacking, which involves the alignment of data cubes from galaxies to flatten the noise and improve the signal. Before I give a lot away, let’s get in the interview and listen to what Andrew had to tell us.

Intro Music: [00:01:42]

Tshiamiso: [00:01:45] Welcome to the Cosmic Savannah today our guest is Andrew Firth, who is a master student at UCT, is it UCT?

Andy: [00:01:49] That that is correct. I’m based at the SAAO and thank you for having me in.

Tshiamiso: [00:01:54] Yeah, thank you for having us. So Andrew will be chatting to us about what he’s studying his masters, but also he’ll be telling us a little bit about his background and how he got into astronomy. Who is Andy?

Andy: [00:02:07] Oh, okay. As you said, my birth name is Andrew Firth a lot of people call me Andy, and I’m okay with that. If I owe something and then in that case, it’s Dennis, that’s always good to have some backup. Well, I was born in the Northern Cape, so that had a big influence on my desire to study astronomy. The night skies there are brilliance if you go to Carnarvon, which is where I’m from. Yeah, absolutely. It’s like fire in the sky. It’s just absolutely amazing.

And also my upbringing, my dad also used to show me many displays on how daylight works and how the phases of the moon work using cricket balls and a candlelight. Since that’s really only ever been one thing that I wanted to do and that was astronomy

Tshiamiso: [00:02:59] You are here doing your research in astronomy please tell us a little bit more about that.

Andy: [00:03:04] Okay. I’m essentially continuing my honors project from last year And it’s in the improvement of, so I can tell you this, the title might be a bit of a word salad.

The title generally went “Improving spectral SNR through cube stacking” and so at no point there, does it sound like I’ve mentioned astronomy?

Tshiamiso: [00:03:34] Yeah, it doesn’t [laughter].

Andy: [00:03:37] But really. This is really tackling what’s a very, very big problem when it comes to HI astronomy or the study of the 21 centimeter line. And so that’s a bunch of astronomy in radio astrophysics in my case where we studied the emission of 21 centimeter long wavelengths through a particular transition in a hydrogen atom.

And so that transition being an electron moving through various states releases a photon and that photon which is this particle of light, moves through the wavelength of that radiation as a length of 21 centimeters. And this is very useful applications in astronomy in that it’s a very long wavelength, so it doesn’t interact much with gases in between. So it travels for very long distances, but there’s a drawback. Everything has some sort of catch.

And in this case, it’s a very weak form of emission. And so the only reason we really see it is because hydrogen is so abundant in the universe. And so even though hydrogen is the most are abundant, the signal, which is the S part of this word called SNR is very weak. So what you want is a very high signal and low noise.

In other words, a high signal-to-noise ratio. And you can do this through many means. And a very popular way of doing it is through stacking data of an object or images of an object. So you take, so in conventional photography, you take multiple images, you’ll stack them, meaning you align them. And then add all the various pixels together and that usually flattens the noise and improves the signal. And of course, you have to do some averaging otherwise you’re not looking at what you think you’re looking at anymore. So you’re looking at something else.

So our task was to take this idea and to move it into three dimensions. So a sort of three dimensional picture of the galaxy. But it’s not the physical aspect of the galaxy, but more the motional aspect of the galaxy. This is very difficult to explain without moving my hands. I’ll try my best to convey it in sound. So I’m not sure if you’ve heard of the Doppler effect.

Tshiamiso: [00:06:18] Yeah, I have.

Andy: [00:06:21] So that works for sound very well. If you’ve heard the whole notion of a train coming towards you and leaving you with the whole, with the hooter. That high pitch when it’s coming towards you in the low pitch when it’s getting away from you. So in the same way, we look at galaxies using a radio telescope and there’s H one gas,that’s the hydrogen gas that’s in and around this, the sort of bowl of galaxy, this bowl of space. And this bowl is filled with, with hydrogen gas and this hydrogen gas isn’t stationary.

So it’s all moving around the center of this galaxy. So it’s rotating just like if you imagine the spiral galaxy, they tend to have a lot of it. That’s all the rotating about the center. And so if you’re looking at a galaxy, let’s take the easiest. If you just picture a spinning CD disc and you’re looking at the edge of that CD disc, one side of that CD disc, that you’re looking at will be coming towards you and the other part will be getting away from you. And so that compresses or stretches the signal the 21 centimeter line that’s coming from this hydrogen. And that gives you some sort of idea of how this galaxy is moving.

It gives you the clumps of gas that’s coming towards you and the clumps of gas getting away from you. And so in my project, we want to improve this by making sure that we align galaxies. And this is further complicated by the fact that galaxies are not all positioned the same in space. It’s all random, scattered all around. And so just like I spoke about, you have to average them. You have to make sure that the image that you’re taking is identical when you add them. Or rather the galaxies inside have the same orientation inside that data cube.

And so my algorithm, rather our algorithm that we’re trying to develop is in sort of phase two of production. Now, we are trying to make it a little bit smarter and that involves using optical properties for when you try and align galaxies inside the data cube. Hopefully, I haven’t spoken to myself into a web.

Tshiamiso: [00:08:52] This is all really interesting. You also mentioned a radio telescope I’m sure all of us have heard about radio all over, but please tell us a bit more about the radio telescope. And is that where you get your data?

Andy: [00:09:05] Yes. So radio telescope is pretty much similar to an optical telescope in that an optical telescope, collects light or photons, or focuses lights to a detector. And uses the wavelengths that we can see, which is in the nanometers range.

I can’t remember exactly, but it’s about like 500 nanometers around there. That’s the length of the wavelength. So there’s a peak and the crest, the distance between those two things is about five and over on the order of nanometers, in the case of radio. Radio electromagnetic lights or radio light, those wavelengths are a lot longer. And a lot of the particles, a lot of the photons bypass and just cannot be detected by an optical telescope. So you have to design a different telescope, which is able to collect photons from a radio source, like HI, the other sources as well, but I wouldn’t dare claim to know much about it.

But in the case of HI, which is 21 centimeter line they work on the same principle, you’re just collecting photos from a source that’s emitting radio, radio waves, radio light. So we use the data from a radio telescope array. And so to get to make data cubes, you need sort of, you need to know the delay between signals from the different parts of the galaxy. In that delay, because, because the galaxy is moving, there’s a delay between when if you again, think about the CD, analogy.

The part of the CD, that’s closest to, you gets released a little bit sooner than the part that’s moving away from you. And so there’s a sort of delay and also lengthening of the wave. And there’s also a delay the spacing between different telescopes in the array for now we’re back on earth now. And we’re thinking about how we’ve placed the telescopes that spacing allows us to infer what’s called phase shift information.

And from that a whole bunch of complicated maths, which I haven’t dealt with myself, but I trust the mathematicians and engineers, allows us to construct a data cube and -my work starts from the, the computer side of things. So I hardly, I haven’t touched the radio in my life to this point. Yeah.

Tshiamiso: [00:11:54] okay. Alright. Okay. So this has been really fascinating to know about and to know of, but why do you do this? What really motivates you to do the work that you do?

Andy: [00:12:06] A question that keeps me interested is how did we all get here? And so one way you can study that is through astronomy and you can look in radio waves, which travel much further than optical waves because of the things about extinction.

And you can look and sure as you might’ve heard before. If you look far, you look back in time as well. So if you look further away from earth, you look further back into the past and you can study the things that are far back in the past, to gain some sort of sense on the evolution of the universe, how galaxies form, how old the things that we see around us in the night sky, how they came about. Because you can see further and further. And I think, and that’s one of the main reasons why I’ve gone into radio, Extra-galactic astronomy.

Tshiamiso: [00:12:59] Oh, okay. So that’s really interesting. I am already motivated myself. [Laughter]

Andy: [00:13:07] Mission accomplished.

Tshiamiso: [00:13:09] Thank you, Andy, for being with us today.

Andy: [00:13:11] Thank you for having me.

Outro Music: [00:13:13]

Tshiamiso: [00:13:23] What an informative discussion we’ve just had with Andrew. His work in radio astronomy sounds very exciting, but yet challenging, especially trying to align the galaxies found and the HI 21 centimeter line as galaxies come in different shapes and sizes. I think Andrew gave us amazing analogies and examples to help us visualize what he is doing.

Astronomy is indeed challenging, but like I said, very fascinating as it gives us another avenue of understanding the universe better. I hope you enjoyed this mini episode with me Tshiamiso Makwela and Andrew Firth, I thank you.

Mini Episode: Beyond the zone of avoidance

with Sambatriniaina Rajohnson

Hosted by Tim Roelf

This week’s mini episode features PhD candidate Sambatriniaina Rajohnson, of the University of Cape Town’s Astronomy department. She explains part of her work trying to advance our understanding of the large scale structure of the universe.

Using the radio telescope MeerKAT, she plans on observing these structures in a region known as the Vela supercluster. This all part of her contribution to the Galactic Plane Survey (GPS).

She describes some of the challenges she faces in studying the region of space hidden by the Milky Way – the formidable Zone of Avoidance.

A 3-D render of the 2MASS Galaxy Redshift Catalogue (XSCz) which highlights the zone of avoidance. This is what our local universe would look like if we could view it from the “outside”, with each dot representing an entire galaxy, and the colours giving us a measure of distance. The zone is created from the Milky Way blocking our field of view. Image credit: T. Jarret

This week’s featured guest

Featured Image

2MASS Galaxy Redshift Catalogue (XSCz): The local universe as seen in the near-infrared spectrum, and displayed in an equal-area projection, with the Milky Way at the centre. The colour of the galaxies pictured (of which there are at least 1 million!) gives us an indication of the distance between us and them. Those that are the furthest away are coloured red, while those that are closer are purple. The galactic plane is that thin line of white/tan coloured stars, and space dust, spreading out from the actual centre of the Milky Way – which happens to be a supermassive black hole! It’s the dust, stars, and black hole that obscure our vision; creating the Zone of Avoidance.
Credit: T. Jarret
https://wise2.ipac.caltech.edu/staff/jarrett/2mass/lss/XSCz_all.jpg

Related links

If you liked the XSCz images and want to find out more about them:
https://wise2.ipac.caltech.edu/staff/jarrett/2mass/XSCz/index.html

Sambatra also recently got featured in a Royal Astronomical Society poster contest. The link below takes you to page with a brief summary of the poster, and a download link so you can check out her poster for yourself:
https://ras.ac.uk/poster-contest/sambatriniaina-rajohnson?fbclid=IwAR1jayJqn4z-hgDDsy6geA1GJ2Ib2bk8yuTVmA6nj7CP5VcsNpRmhyB58-g

Mini episode produced and hosted by
Timothy Roelf (University of Cape Town)

Transcript

Transcribed by Tim Roelf

Tim: [00:00:00] Hey everybody. And welcome to this week’s mini episode of the Cosmic Savannah. My name is Tim Roelf, and I’ll be your host for today. As some of you already know Jacinta, and Dan, have gotten in several of us trainees to perform our own little mini episodes for you guys to help us to develop our skills as podcast hosts, editors, and transcribers.

The process has been really awesome, and I hope you guys have been enjoying our work so far. This week, I interviewed Sambatra Rajohnson. She’s a PhD candidate at the University of Cape Town’s Astronomy department. And her work involves in completing a Galactic Plane Survey (GPS), some of the cool bits about Sambatra’s research involes the fact that she will be looking at a region of space known as the Vela supercluster that lies just beyond the zone of avoidance.

So if you guys just scroll around the Cosmic Savannah blog site here, you’ll be able to see one of the images has a picture of what the Zone of Avoidance looks like along with a little bit of a description. Essentially, it’s just the obscuration of dust and other stars that creates this regional space that we can’t actually penetrate.

If you guys are a little bit confused about what I mean by, or what Sambatra means, by the galactic plane, the featured image on this week’s episode is a all-sky survey that was done in the infrared spectrum and shows our local universe. Right at the center of the image you’ll see a thin white band with like tan and white colored stars and dust.

That is the galactic plane. So essentially it’s just this flat line where most of the stellar matter lies, and at the center of which is a supermassive black hole. And that creates this obscuration. And just some last technical terms before we can answer the interview, Sambatra mentions the words: uniformity and isotropy.

Now uniformity, sometimes known also as homogeneity, just means that the universe on a large enough scale has the same spread of matter, or stars, stuff really, to put it simply if you just take two large enough areas of the universe and you compare the two of them, they will have the same spread of matter across them.

And isotropy means, that the universe is the same in every direction. So it doesn’t matter if you look forward or backwards, the universe will be the same. Now enough of me talking. Let’s get down to this week’s episode.

[00:03:16] [Intro music plays]

Tim: [00:03:22] What’s up everybody, and today I’m joined by Sambatra Rajohnson. She is a PhD candidate at UCT. Welcome to the show, Sambatra.

Sambatra: [00:03:34] Hi Tim, thank you for welcoming me.

Tim: [00:03:38] Yeah, that’s no problem. I have a few intro questions quickly. So for people who don’t know you, you’re not actually from South Africa. So if you can tell us a little bit about where you’re from, and how you managed to get to UCT.

Sambatra: [00:03:51] Okay. It’s a bit of a long story, but I will try to summarize it. So I am from Madagascar and I did my undergraduate studies and I obtained my master degree from the University of Antananarivo in the capital. And during the same period, I was also participating to the DARA are basic program DARA for Development in Africa with Radio Astronomy.

And it was basically a technical training in radio astronomy observation. And from that one of our lecturer, Professor Claude Carranan, he proposed to me to do a PhD with him at the University of Cape town and I’ve accepted. So that’s why I ended up here in Cape Town.

Tim: [00:04:33] Cool, that’s very cool. And how are you finding it in Cape Town so far? Is it cool?

Sambatra: [00:04:37] Oh, it’s a very beautiful city. It’s also my first time, like really living abroad. So I’m trying to adjust myself with all the changes, but now I see it’s a very good place.

Tim: [00:04:49] Okay. That’s awesome, and so you mentioned that your project is in radio astronomy. Could you tell us a little about that?

Sambatra: [00:04:57] Okay. So I’m working with Professor Renee Kraan-Korteweg now, and Dr. Bradley Frank on the Galactic Plane Survey or GPS. And we are using the radio telescope MeerKAT, which is here in South Africa. And we are trying to find structures of galaxies that are located behind the Milky Way plane by searching for the neutral hydrogen, or H1 emission, which only radio telescope can trace.

Tim: [00:05:28] Okay. So they’re obscured by the galactic plane. How you actually able to tell. That’s something behind the galactic plane.

Sambatra: [00:05:41] Yes. So the zone, which is behind that Milky Way plane that we are trying to look at is called the Zone of Avoidance.

Tim: [00:05:42] That’s a scary name.

Sambatra: [00:05:45] Yes, a little bit. Most of astronomers are trying to avoid it, due to the strong dust obscuration, and strong steller density which hides mostly everything behind it, especially if you’re looking at optical wavelength. But, if we use other telescopes or other wavelengths, such as infrared or radio, so this obscuration is reduced. So we are not really affected so we can see things behind the Milky Way using, for example, radio telescopes.

Tim: [00:06:15] Okay. That’s very cool. Very, very cool.And your work. In that zone of avoidance, what are you looking for? Are you looking for new galaxies?

Sambatra: [00:06:26] So we are trying to to complete the mapping of the large scale structure of the sky. So we are tying to find structures that are hidden behind the Milky Way. So we have, for example, a particular region of interest, which is the Vela supercluster, which is located situated towards the constellation of Vela.

So the GPS survey will allow us to find hidden structures. How filaments are connected.

Tim: [00:06:56] Sorry, just to interrupt you. JPS, what does that stand for?

Sambatra: [00:07:01] Oh, the galactic plane survey.

Tim: [00:07:05] Oh yeah, the GPS you said.

Sambatra: [00:07:06] Yes. So we are trying to find if the hidden structures, how filaments are connected there behind the Milky way. Are there, for example, crossing walls from that Vela supercluster?

Tim: [00:07:20] Yeah. Okay. That’s cool. But I’m not very familiar with the filaments. Could you give us a little bit of an explanation on that please?

Sambatra: [00:07:27] Yes. So from the cosmological principle, it states that the universe is uniform and isotropic. However, when we are looking into details, so we are like zooming into the universe. We can see that actually the universe is highly structured. So for examples, galaxies are connected each other to form elongated filaments, or walls. And there are also small, a large concentration of galaxies, which form clusters of galaxy groups and superclusters. And between them, they are also just large empty voids. Yeah. So are forming what you are calling the cosmic web. So like web like structure in your universe. Yeah.

Tim: [00:08:09] So that’s the large scale structure. So everything is connected in what approximates a web essentially, but not like a 2-D web it’s in 3-D.

Sambatra: [00:08:23] Yes

Tim: [00:08:24] Which is really, really cool. That’s fascinating. That’s awesome. I was wondering your work, you said that by working in the radio, you’re actually able to penetrate past the galactic plane and into the zone of avoidance, which you wouldn’t be able to do in optical.

How does your work then work with the optical astronomers? So how are you guys able to back each other up essentially and provide more information into your work? For instance, if an optical astronomer would also like to, then would they be, would it be possible to look into the zone of avoidance and help you add or…

Sambatra: [00:09:06] So for optical astronomers, they cannot really look entirely at the zone of avoidance. Maybe, there will be some part where they will be able to look into, but very small part of it. And they have already tried to like make the mapping of the entire sky, but then they miss out the zone of avoidance. So maybe they have obtain some images of galaxies that are next to the sort of avoidance, but not exactly in the middle of the packed zone. There have been also infrared astronomers who try to look into it. So they have found more galaxies, so the galaxies in the zone of avoidance have been extended, but it’s not yet fully locked mapped. So that’s why you have to add with radio bands so that you can find more.

Tim: [00:09:51] Okay, that’s very, very cool. One final question, I’m just interested, So why would you use, you know, just getting into astronomy, what would you say to them, to interest them, in coming say to a presentation on your work. I suppose.

Sambatra: [00:10:06] Oh, I think my work is like quite a challenge because most of the astronomers are trying to avoid that zone. But we are looking directly into it. So it’s a challenge to be able to discover a galaxies that are being never observed in optical before, or even never found before. So yeah,

Tim: [00:10:25] So you’re kind of a pioneer. That’s awesome.

Sambatra: [00:10:32] Yes it’s challenging.

Tim: [00:10:35] Do you get to name any galaxies or stars that you find in the zone of avoidance?

Sambatra: [00:10:42] From now on, I’m just starting my project. So I don’t know yet about that. Like how are we going to name them? Maybe according to the telescope because you will be using MeerKAT. So maybe the name of the stars will be linked to the MeerKAT telescope, but I’ve not yet thought about it.

Tim: [00:11:00] Oh, I think you missed my question. Its like, would you name it, you as Sambatra, would you be able to name it because you found it, would you be able to name anything?

Sambatra: [00:11:11] From now I don’t know yet whether I’ll be able to, or not.

Tim: [00:11:14] Ok, we can look forward to a few galaxies or stars being named after Sambatra. That would be very cool.

Sambatra: [00:11:19] I hope to.

Tim: [00:11:22] Thank you very much for your time today. I’ve thoroughly enjoyed this conversation and I hope to see you again. Next time.

Sambatra: [00:11:29] Okay. See you.

[00:11:30] [Outro music plays]

Tim: [00:11:37] And that’s it for this week’s episode. If you guys had fun and want to know more about this topic, I’ve left the link in the description of the blog post above to a series of posters that Sambatra submitted for the Royal astronomical society. I highly recommend you guys go check it out. They’re really informative posts and they’ve got some really, really cool graphics as well that I think everybody can appreciate and until next time, cheers.