Federal astronomers now determining where fast radio bursts come from

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They’re out there in the universe – bursts of radio energy coming from distant galaxies. These fast radio bursts (FRBs) were first identified a few years ago. Now, thanks in large measure to the work of Dr. Matthew Kerr, we know exactly where in the cosmos at least some of these FRBs originate. Kerr is a research physicist at the U.S. Naval Research Laboratory and he joined Federal Drive with Tom Temin  for more details.

Interview transcript:

Tom Temin: Dr. Kerr, good to have you on.

Dr. Matthew Kerr: Good morning. Thank you very much for having me.

Tom Temin: Give us the context of this work for what you did get a major award. But FRBs out there in the cosmos. What is the significance of all of this?

Dr. Matthew Kerr: So fast radio bursts were a huge surprise for all of us in the radio astronomy and the larger astronomy community that were found about 15 years ago, serendipitously, so many things in astronomy are people were looking for pulsars, which are another type of radio source that were found 50 years ago, when they were looking through the data, they found this mysterious pulse radio light that lasted only about a millisecond. So when we say fast, we mean faster than the blink of an eye. And nothing like this had really been seen before. And it was the first one and the only one that was seen in that data set. So people had no idea what it was whether it was a real signal or interference. And if it was a real signal, what it could be or where it was coming from. So it set off a great mystery. And until recently, we didn’t really have the technology to solve that mystery. All our telescopes could do was say, hey, here it is, but not where it was coming from. thing we’ve been able to do recently is say, hey, here it is, and there is where it came from.

Tom Temin: So a millionth of a second is not long enough for it to be say some cosmic Michael the plumber add it, we just know that it’s in the radio frequency range. And what is the evidence of it, you can’t hear it directly, it’s something you infer from a large data set.

Dr. Matthew Kerr: Well, just like any other type of light radio emission, you can see it. So you know, you see an optical flash, you can say, hey, it wasn’t bright. Now it’s bright. And now it’s not bright again. So that’s definitive evidence, the special thing about these is that they’re dispersed. What that means is that the high frequencies arrive below the low frequencies. So you remember back in your science class, maybe sending light through a prison, that medium that prism causes light with different frequencies to travel, different speeds, radio waves, when they pass through space, which is full of electrons have the exact same process applied to. So these bursts are dispersed. And that’s their Hallmark that we know they didn’t come from someone’s cell phone or microwave, but that they came from the cosmos. And so we were able to take that signature from the get go with these fast radio bursts. It’s kind of why they’re special, and how we’re able to tell them to come in from great distances.

Tom Temin: So it’s important to know then that they did come from someplace out there and not bouncing off source in our own galaxy or even on earth. And so how were you able to tell where they came from? You’ve named a specific galaxy, somewhere really far out one that is the source of at least one of those particular bursts.

Dr. Matthew Kerr: Yeah, that’s right. The radio telescope that discovered fast radio bursts cannot pinpoint where they come from. It’s an analogy that radio astronomers hate to make. But it really is kind of like just a microphone that has no directional capability. In fact, it does have direction capability. But it’s not enough to pinpoint a galaxy with this new discovery uses something called an interferometer. And it is an array of telescopes. And because they’re, they’re big, they have the angular resolution that lets you determine where they’re coming from. The real trick is that because these are arrays, they have many antennas and a huge data volume. So we were never able before, to find these bursts quickly enough to record the data, and then determine their position accurately. By using kind of modern computational techniques, like GPUs, graphical processing units, which are being used throughout science these days, as well as some clever algorithms, we can now analyze the light right as it comes in, determine if there’s a fast radio burst in it, potentially using some machine learning techniques, and then dump out our data. And it’s this kind of technological breakthrough that allows us to actually pinpoint the position precisely to distant galaxies.

Tom Temin: And just out of curiosity, where did this particular burst come from?

Dr. Matthew Kerr: It’s an unmemorable galaxy name. And there are a number of them now that we’ve determined which galaxies they’re coming from. The most interesting one right now is repeating fast radio bursts, and it’s coming from the galaxy. That’s Giga, parsec. away. So that’s 3 billion light years give or take. And remember that a light here is the distance light goes in a year, and it’s about 6 trillion miles. So it’s quite distant, even by cosmological standards.

Tom Temin: Yes. So if those aliens are on their way here, that’s going to be a while till they get here physically.

Dr. Matthew Kerr: It’ll be a while, and they’ve got a really powerful transmitter.

Tom Temin: Okay. And I wanted to ask you about the award you got from the American Association for the Advancement of Sciences Newcomb, Cleveland prize. That’s a big deal, isn’t it?

Dr. Matthew Kerr: Yeah. This was really surprising to me, because this is not a word that I was familiar with. And until the announcement should have been my inbox, I didn’t really know what it was all about. But the Triple S publishes the journal Science, which is one of the two high profile publications that are kind of cross disciplinary. So they get publications from medicine, physics, chemistry, and kind of the high impact. papers from each of those fields tend to go to the journal Science and Nature, although each field does their own thing. So science each year reviews the articles that are submitted and picks kind of what they feel is the most interesting or groundbreaking work and awards if this prize, so it was real honor to receive it. And I’ve got to give a great shout out to the lead author Keith Bannister, who is really the kind of technological genius behind this project working in Australia.

Tom Temin: Sure. And this work is being done by the Naval Research Laboratory. Is this basic research you’re doing? Is there some tie in to naval activities? Or because often federal labs do kind of applied research on behalf of the sponsoring agency?

Dr. Matthew Kerr: Yeah, absolutely. I don’t know We do everything from basic research, to very applied research, we have a vision that when we’re doing basic research to will ultimately have used for the Navy. So our group is the high energy space environment group. And we’ve traditionally worked with gamma ray astronomy. And so for instance, the crossover there is by understanding gamma rays and cosmic rays, we can understand how they affect the Earth’s atmosphere. And the ionosphere. And this is important for a space weather being able to predict how well or over the horizon radars are going to work, how reliable or information systems will be. As there’s always a tie in, we also need precision navigation and timing using celestial sources. So this kind of falls into that same portfolio, we’re doing basic science, but with instrumentation that can definitely be useful for the Navy.

Tom Temin: And as a scientist, who is involved in astronomy, and looking out there, so to speak, do you spend most of your time looking through the scope of a telescope or most of your time looking at a screen doing data analysis,

Dr. Matthew Kerr: I definitely spend most of my time looking at a screen and doing data analysis. But like many of my colleagues, I’ve spent some time observing overnight, especially in my last postdoc, when I was doing radio astronomy, I would frequently observed during the day and overnight.

Tom Temin: And having discovered the source in the cosmos of these repeating radio bursts, what’s your philosophical take on what’s going on out there.

Dr. Matthew Kerr: So we’re still just scratching the surface with bastard universe. You know, we’ve observed hundreds now, but only a few of them are known to repeat, we’ve just discovered the host galaxies for a handful. So we have some ideas of what’s going on, we think that they are caused by something called magnetars, which are magnetized neutron stars. They’re born when massive stars former massive than our sun, die, and leave behind a very compact magnetized remnant. And when they’re young, they have the energy that they could potentially produce these fast radio bursts. So just on our sample of a few, that looks like that might be the case. But we really need to detect some more to see whether, you know, this holds up. There are many that have never been observed to repeat. So we don’t know if they’re the same type of object or not.

Tom Temin: And beyond this, what other projects are you working on at the moment?

Dr. Matthew Kerr: I do a lot of work with the Fermi gamma ray Space Telescope. That’s what I did my PhD on. This was a NASA mission launched in 2008. And it’s still orbiting the Earth doing good science. And I particularly study pulsars, which are similar to the main guitars I just mentioned. And what we try and do is time them very precisely, and by looking for perturbations and the signals, they’re very good clocks. And if we see perturbations in the signals, we can infer the presence of something moving the distance between those pulsars in the earth, such a thing might be low frequency gravitational waves, which were predicted by Einstein many years ago, and are thought to be filling the universe. So that’s one of the things that I’m working on right now, aside from these FRBs.

Tom Temin: Yes, in fact, I had an interview on that discovery a couple of years ago, and I forget the details, but I think the news the Yeah, it was literally a wrinkle in time, I think is what the press covers.

Dr. Matthew Kerr: That’s right.

Tom Temin: Sure. And final question, it sounds like given the work and the range of things you’re involved in that the Naval Research Laboratory, ranks up there with any academic institution in terms of supporting interesting and basic and relevant research.

Dr. Matthew Kerr: It’s a really great place to work. I’ve never experienced anything like it, we have the resources to do our own hardware developments, and to put it on satellites and test them, and even to launch them into space. So right now we’re working on an instrument that will go up to the space station, hopefully sometime within the next year to detect gamma ray bursts. They’re kind of like high energy analogues of these fast radio bursts. And we’ve designed instruments built it in house and we’ll launch it through the DVD. So that’s an opportunity that just doesn’t really exist in academia. So it’s a really great place to work.

Tom Temin: Dr. Matthew Kerr is a research physicist at the Naval Research Laboratory. Thanks so much for joining me.

Dr. Matthew Kerr: Thanks very much for having me on. Let me tell you about the great work we’re doing in our own.

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