Dr. Kimberly Arcand is a Visualization and Emerging Technology Scientist at NASA’s Chandra X-ray Observatory at the Center for Astrophysics, Harvard, and Smithsonian.

In this episode of The Show About Science, Nate and Dr. Arcand dive into the mysteries of the universe illuminated by Chandra’s use of X-ray light. From uncovering the intricacies of black hole cosmic recycling processes to exploring the aftermath of exploded stars and the mesmerizing pulsars emitting high-energy particles like cosmic lighthouses, this is a galactic tour like no other!

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Photo credit: NASA/CXC & J.Vaughan

Transcript:

Nate: Hello everyone and welcome to another episode of The Show About Science. This is your host, Nate, and on today’s episode we are talking about the universe and all of the crazy things that you can observe when you look beyond what your eyes can see.

If you’re out there thinking, “Hey Nate, how on earth does somebody see beyond what their eyes can see?” Well, have no fear, because helping us on this cosmic journey is Dr. Kimberly Arcand. 

Kimberly Arcand: Hello, it’s so nice to be here. 

Nate: Kim’s title is a bit of a mouthful. She’s a visualization scientist and emerging technology scientist at NASA’s Chandra X-ray Observatory at the Center for Astrophysics, Harvard, and Smithsonian.

Kimberly Arcand: And so that is kind of a mouthful just to say essentially I get to, yeah, work with incredible data of our universe every day and it’s pretty fun. 

Nate: So, you’ve worked at the Chandra X-ray Observatory. Emphasis on the X-ray Observatory part. What even is that? 

Kimberly Arcand: Yeah, so Chandra is a telescope that has been designed to detect X-rays, like from very hot regions of our universe.

And you can think of like the x-rays that you might have gotten if you’ve ever gone to a doctor or a dentist if you had like a broken bone or if you’ve had a cavity in your tooth. Those types of x-rays, they’re really important because they’re so highly energetic and you can see through things that you can’t otherwise see in different kinds of light.

Nate: So, these are the same x-rays that we’re using to see broken bones. But how do they help us see things in space? 

Kimberly Arcand: Yeah, so you can kind of think of the universe as like a baseball field. And if you could only look at that baseball field with optical light, the kind of light we see with human eyes, you’d probably only be able to see the third base foul line.

Intergalactic Baseball Announcer Guy: Welcome to game seven of the universe series. It’s a celestial showdown between the Milky Way Pulsars and the Andromeda asteroids. And so far this series has been out of this world. It’s a beautiful night for a game, but for all you Earthlings watching with just optical light, your view is as narrow as a wormhole.

Kimberly Arcand: But as soon as you start looking in other kinds of light, like X-ray light that Chandra looks at, or infrared light from the James Webb Space Telescope, or microwave light, radio light, all of that stuff. Now you’re starting to get a better picture of who’s playing on the field, what the score might be, where the baseball even is, right?

So we need all these different kinds of lights to be able to understand our universe. 

Nate: So it’s like we only have one slice of the picture when we look at the universe with the naked eye. And Chandra provides us with another critical slice. And that lets us visualize all sorts of cool things. 

Kimberly Arcand: Yeah, so X-ray light gives us very specific glimpses into the cores of galaxies where supermassive black holes tend to reside through arms of dust and gas where we can find things like exploded stars, neutron stars, pulsars, all of these different kinds of objects in our universe that are important to learn about, but some of them can only be captured in X-ray light.

And so Chandra really has opened up a window, a new window onto like our high energy universe, these things creating all of this extreme energy, right? The light from an exploded star, a supernova, can be essentially brighter than all of the light from its galaxy. So these are pretty intense processes and objects that we get to look at.

But because it’s x-ray light, it’s invisible to humans naturally, right? right? So we had to create this telescope and then write software to be able to translate what we’re capturing out in the universe to something we can see or perhaps hear down here on Earth. 

Nate: And so you mentioned exploding stars aka a supernova.

So have you actually seen one happen and seen what that looks like? 

Kimberly Arcand: So in our galaxy, a star explodes about every 50 years or so. So we haven’t seen one locally in our galaxy with Chandra. However, Chandra has seen the remains of them, so what happens after those stars blow their guts apart and kind of like, you know, spread out into the universe.

There was a pretty famous supernova that’s called 1987A that happened back in 1987 that telescopes have been monitoring for a while because it was like a wonderful opportunity to capture that in real time. Chandra wasn’t yet launched but it has been studying it since it launched in 1999 and so that is a really good example of a nearby but still extra galactic exploded star that’s great to be able to look at over time.

And then of course Chandra has absolutely captured new supernovas that have occurred in other galaxies. So they’re not in quite as much detail as we can get when they’re more local, but it really does give us a lot of really cool information. 

Nate: And so what has for you personally been your favorite thing that you’ve been able to study or observe with the data from the Chandra X-ray Observatory?

Kimberly Arcand: I, you know, I have to go back to the very first object we ever released from Chandra which was called Cassiopeia A. It is a supernova remnant and I think it’s because we’ve looked at it so many times. It’s a star that exploded about 10,000 light years away from us. A light year is a distance, satellite travels in a year about 10 trillion kilometers and so 10,000 times 10 trillion kilometers give or take.

And when we can look at that Chandra, we see this incredibly detailed stellar barf and the barf is really beautiful. We can color code it when we have enough information. We capture all of these edges and the detailing so we can see where there’s like pockets of iron and silicon and calcium and sulfur and color code it like you would a weather map to be able to showcase where all of that sciencey goodness is wrapped up inside that stellar barf.

So we’ve looked at that now, gosh, hundreds of times and have like millions of seconds of data on it. And it’s like the supernova that keeps on giving because it just offers us such a view into a star since its death, but also learning about a star and its death helps tell us about what it was like during its life.

You know, it’s kind of like a CSI crime scene investigation.

Nate: And so what would happen after all of that stellar barf was dispersed across the galaxy?

Kimberly Arcand: Yeah, that’s a great question ’cause that stellar barf is really important stuff, right? The iron that’s in our blood, the calcium that’s in our bones, the oxygen that we breathe, right? that that stuff that we have here on Earth came from previous generations of stars that exploded their guts out all over the universe and then slowly dispersed out and was caught up into new clumps of gas and dust and then turned into new stars and planets right so it’s this beautiful cosmic recycling program that this stellar barf is a really important key to.

Nate: And so how long would that process take? 

Kimberly Arcand: Oh, it takes a long time. It can take many, many, many millions to billions of years, right? You can think of the formation of our own solar system that occurred over quite some time. And so these things take long periods of time on the human scale, but the universe is patient.

So the universe has plenty of time for all of these things to kind of come together, coalesce and create new generations of stars, new generation of planets, new generation perhaps someday of people or some other form of life. Who knows?

Nate: So that process would take a long time, but how long would like a supernova take to occur from the beginning to the end when the star is fully exploded? 

Kimberly Arcand: So stars that are kind of small and dim, they last a really, really long time. Things like brown dwarfs could last perhaps, I don’t know, 50 billion years or more.

Things like our sun, they tend to live a pretty good amount of time as well, perhaps 10 billion years or so. Our sun is in like its halfway point if you will. But then these massive stars, they live their lives in like really fast and furious kinds of ways. So they’ve got much shorter lifespans and they’re kind of like a constant push and pull, right?

It’s a constant push from the force inside and then the constant pull because of the gravity because they’re so massive. It’s kind of like every day is a bit of a battle. So they live these short lives because of that, so much pressure and so much pull, and they burn their energy at a really fast rate.

So what happens is as they’re burning up their fuel inside their core, stars that are really massive can build up heavier and heavier elements until eventually they get to iron, and then it just becomes too much and they’ve run out of fuel, their core collapses, and they explode their guts out all over the place.

That process of the actual explosion takes very, very little time. It is very fast, like we’re talking seconds. And then after that, it can dissipate out depending on the size of the star itself. Sometimes a star can be so massive and its explosion so crazy wow, that it can just obliterate itself completely.

Other times it can form into a black hole. Other times it can form into something like a neutron star which is a really super dense core of a star that’s perhaps like the size of Manhattan. And then the rest of the stellar barf that might be left behind can slowly dissipate out over the course of thousands of years.

So the time scales can be so different, right? It can take a while for it to kind of run out of its fuel, but the explosion super fast and then depending on how big that star was and how massive the explosion, how slowly or how quickly it sort of dissipates out into the universe can depend. 

Nate: Wait, okay, so you said that neutron stars are usually about the size of Manhattan?

Kimberly Arcand: Yep, yeah. 

Nate: So like this big, or I guess not big, but uh this really dense energy-filled core of a star is compressed into something that’s way smaller than even the earth? 

Kimberly Arcand: Yeah, so like you can think of the force of crushing down all of this stuff that would have been in the star down into something super, super, super, super, super dense, right?

So think of like, I don’t know, if we could generate some kind of force strong enough to crush like all the emptiness out of a rock the size of a football stadium, that rock would be squeezed down to the size of a grain of sand and would still weigh 4 million tons, right? So these are like really extreme forces that can occur out there in the universe.

When that central part of that really big star collapses in on itself, what it leaves behind is so dense that even though sounding like the size of Manhattan sounds big kind of, ’cause on the human scale, that’s still kind of big. On a universal scale, that’s been compacted down quite a bit. Like it’s a really amazing amount.

And then sometimes with those leftover stellar, I don’t know, zombies, if you will, those leftover dead star bits, um, these really intense fields can form and they can also start to rotate. Right. And so if this neutron star, that leftover core is rotating like really rapidly, then you’re going to create something called a pulsar that has incredible like volts coming out of it like quadrillions of volts speeding around at a really intense speed so it like creates these I don’t know deadly blizzards of high-energy particles which sounds scary but we’re far enough away from them I don’t want to get scared. So the universe is extreme. 

Nate: So these pulsars, could those like shoot out electricity or something like that that could then disrupt I mean probably not our solar system but a different solar system or another star or causing something like that?

Kimberly Arcand: Yeah pulsars do have these high energy particles and they can produce these beams of radiation at different kinds of energies and they’re kind of like a lighthouse beam, right?

That’s like rotating around and they’re really important in science because they can be very dependable too. So you can kind of use them to study different kinds of things in the universe. One of my favorite pulsar is called the Crab Nebula and you can see this kind of really beautiful ring-like structure and you can see the sort of like jet-like feature.

It’s one of the youngest and I believe one of the more energetic pulsars known or at least has been over time. And things like that can definitely be disruptive to the area around them. Those are at smaller scales. I think when I think of things that are disruptive at larger scales, I think more of things like black holes with incredibly intense jets coming out of them.

Some of them, let me see, there’s this one black hole in a galaxy nicknamed the Death Star Galaxy. I think its proper name was 3C 321 if I recall. But it was called the Death Star Galaxy because it was this supermassive black hole and its core was just unleashing a tremendous amount of energy. And the beams of those particles were going so far out that it was going well beyond the edges of its galaxy and knocking a tinier, smaller galaxy next door.

And yeah, I wouldn’t want to be that little smaller galaxy getting knocked upside its head by this super massive, this intensely massive, super massive black hole. And that’s why they nicknamed it the Death Star Galaxy from Star Wars. So there are these incredibly powerful things that are out there in the universe that can be disruptive.

But, but, but things like black holes, they have a bad reputation for being these cranky monsters going through the universe vacuuming things up, you know. But it’s not necessarily the case or not always the case. So black holes can be, like exploded stars, an incredible system of cosmic recycling. And that’s really important, I think, overall, it seems, to the health and safety of their galaxies.

Some of them can be very green, so they’re like responsible for the care and feeding of their galaxy, which I think I think it’s kind of neat when you think about it. 

Nate: So how would a black hole actually be helpful to a galaxy? Like caring for instead of just sucking everything up? 

Kimberly Arcand: Yeah, well, for the most part, black holes have this reputation of being cosmic vacuum cleaners because I think people think they do suck things up.

I mean, there are rogue black holes, sure. But things can orbit around a black hole perfectly well. Like if we, with a magic wand, turned our sun into a black hole tomorrow, which we can’t do because the sun’s not big enough to do that, but if we just did it for fun, Earth would be in a relatively safe distance from a black hole that size.

We would just continue to orbit. It wouldn’t disrupt it. I mean, we would be disrupted for other reasons because we would no longer have light that we need. But as far as like where we are, we would be fine. We wouldn’t be sucked in. So black holes can exist quite well with stuff around them. It’s just, if you get too close, then that tug, there’s no escaping it.

So there are, I think, really interesting things like that about black holes that are fun to think of. But for the most part, other black holes can do things like they can essentially be the beating hearts of their galaxies, where on a time scale of say, five or maybe 10 million years, They pump out material and energy into its environment.

And so what that does is that can enable different stuff to form, right? It’s like you’re giving a little shock to the home galaxy that you live in. So it just, yeah, all of that energy, right? All of that material can be useful for new generations of stars or stuff. So yeah, they can be these really green recycling centers.

Nate: So the black holes could actually release some matter and that could then go to other planets and things like that in the galaxy? How would that work?

Kimberly Arcand: Yeah, so by releasing all of that stuff, right? It can trigger things like new stars to be formed. It can create cavities and well, fill in cavities, I guess, with hot gas.

It can create shock waves, which are kind of like sonic booms. So all of this disruption, all of that high energy goodness can create new generations of stuff to be formed. And that kind of disruption can be good. If you think of a pool of water, if you just have a little pond somewhere and there’s circulation in that pond.

The pond can get really stagnant and you know some yucky stuff can grow. I’m a gardener so I’m gonna go to gardening metaphors I guess. But if you have a little fountain in the middle of that pond, if you’ve got something circulating in there and the water is being taken care of, there’s some energy that’s being sort of you know added into that environment, then it can keep things healthier and it won’t stagnate.

So that’s the kind of thing that this type of energy output from things like black holes can do. They can help prevent things from getting too stagnant. 

Nate: Okay, so in the end what is one big question about the universe that you would like to know the answer to? 

Kimberly Arcand: Oh well that has to be is there a life somewhere else?

You know scientists that are studying things like exoplanets, planets beyond our solar system, they are finding some of the weirdest worlds. Things like worlds where it rains glass sideways at like 1,500 miles per hour, lava worlds, worlds where it rains rubies and sapphires, worlds with like diamond cores, all of these incredible sounding places that are not good for humans to live on.

So my question is always like what other worlds exist that we don’t yet know of and what does it take to have a hospitable place, you know, the Goldilocks place not too hot, not too cold, not too dry, not too wet, all of that. The perfect spot, right, for other types of life to develop. And I think hopefully someone in your generation will figure that out someday.

Nate: Wow. Well, this entire conversation has been very interesting. So before we wrap it up, if anybody would like to learn more about some of the topics that you study, is there anywhere that you would direct them? 

Kimberly Arcand: Yeah, I would definitely direct them to the Chandra website. I think it’s been an absolute dream working for this mission for the past 25 years and Chandra has just uncovered so many gems in this little treasure chest of a universe that we have.

So yeah, check out the Chandra website at chandra.si.edu or just use your favorite search engine to look up Chandra and exploded stars or black holes and you’ll come across some pretty fun stuff. 

Nate: All right, thank you for being on the show. 

Kimberly Arcand: Thanks so much for having me. This was really fun. You don’t get to talk about stellar barf every day, so here we are.

Nate: Yeah.

Intergalactic Baseball Announcer Guy: Hey, Nate. 

Nate: Yeah? 

Intergalactic Baseball Announcer Guy: You really knocked this episode out of the park. 

Nate: Thanks, intergalactic Baseball Announcer Guy. 

Intergalactic Baseball Announcer Guy: You are so welcome, Nate. This interview was a meteoric success. You were like a gravitational force pulling out the most enlightening insights from Dr. Arcand. 

Nate: Okay, I think that’s enough “spaceball” puns.

Wait, hey, how about you read the credits? I’ve got a black hole to get to. 

Intergalactic Baseball Announcer Guy: Sure. Music on this episode comes from Epidemic Sound and Descript. The show about science theme song was written by Jeff, Dan, and Theresa Brooks. Thank you to the entire constellation of contributors who make this show a cosmic success.

And a special shout out to our stellar audience, whose curiosity fuels our cosmic adventures. Remember to subscribe wherever you get your podcasts. 

Nate: Okay, Dad, I think it’s time to shut this guy off. See you on the next episode, everyone. Bye!