Ignacio Taboada, professor in the School of Physics and member of the Center for Relativistic Astrophysics at Georgia Tech, has been elected as spokesperson for the IceCube Neutrino Observatory, a collective of more than 300 scientists worldwide who work to detect neutrinos and other high-energy streams of subatomic particles reaching Earth from deep space. The system of sensitive detectors — which takes up a cubic kilometer of South Pole ice — began in 1999 and has already yielded major discoveries about neutrinos, which are near massless subatomic particles that can travel unhindered for billions of light years from the most extreme environments in the universe to Earth.
Taboada joined AMANDA (The Antarctic Muon and Neutrino Detection Array), IceCube’s predecessor project, as a Ph.D. student in 1998 and has since added a number of major research responsibilities to his portfolio as IceCube has grown. In 2017, Taboada and Ph.D. student Chun Fai Tung made significant contributions to the study of the first-ever detection of a neutrino in coincidence with a gamma ray flare from a "blazar" — a type of galaxy with a super-massive black hole, in which a jet produced near the black hole points towards Earth. The blazar was the source of a high-energy neutrino that set off IceCube detectors.
In recent years, researchers in the School of Physics at Georgia Tech have helmed a number of major collaborations and communications within the realm of astrophysics research and discovery — including the Nobel Prize-winning successful search for gravitational waves, through which a team of Tech’s astrophysicists joined thousands of scientists from around the globe in the LIGO (Laser Interferometer Gravitational Wave Observatory) detection effort. Laura Cadonati, professor in the School of Physics and the current director for Georgia Tech’s Center for Relativistic Astrophysics (CRA), has served as LIGO’s deputy spokesperson.
As Taboada, a member of CRA, prepares to begin his tenure as IceCube’s spokesperson this May, he echoes that arc of leadership and the unique role that Georgia Tech and the School of Physics play within IceCube, LIGO, and other projects — and what that may mean for the future of other large-scale undertakings in this space:
“I think the relevance is that big science, as understood in terms of large scientific collaborations, is now clearly an important part of the scientific portfolio at Georgia Tech,” Taboada says. “If you look at the way that science has been changing within Georgia Tech, it’s clear that there are many changes for the better. The scientific output of Georgia Tech is improving, and improving over time. And I really hope that this is a sign of more things to come for physics and for science in general — and I really am very hopeful that Georgia Tech is going to play a big role within Gen2 (the next phase of IceCube’s development).”
Taboada recently joined Madeleine O’Keefe, communications manager at the University of Wisconsin-Madison IceCube Particle Astrophysics Center, and Darren Grant, current IceCube spokesperson and professor at Michigan State University, by video conference for a conversation on IceCube’s progress and plans:
IceCube Spokesperson Q&A: Ignacio Taboada and Darren Grant
By Madeleine O'Keefe
Darren Grant has seen quite a few exciting things during his time as IceCube spokesperson. From pinpointing a cosmic accelerator to measuring a tau neutrino appearance to detecting a Glashow resonance event, the last four years have been exciting for the South Pole neutrino telescope and the team of scientists behind it. But Grant, a professor at Michigan State University, has served his maximum two terms as spokesperson and will soon hand the reins to IceCube’s newly elected leader: Ignacio Taboada, professor at the Georgia Institute of Technology. Elected in February 2021 by the IceCube Collaboration, Taboada officially begins his term as spokesperson on May 1.
Being the spokesperson for an international collaboration as big as IceCube can be a challenge, but Taboada is up for it. With IceCube at an exciting juncture, with more scientific discoveries and physical expansions on the horizon, we chatted with Grant and Taboada (over Zoom, of course) to hear what each had to say about what IceCube has accomplished and where it is headed in the future.
Question: What were some of the highlights in the last two years of IceCube?
Darren Grant: There have been so many, it’s really tough to pin down specific highlights. Tau neutrinos have been popular: We had the first measurements of tau appearance with IceCube DeepCore in 2019 and then reported the first observation of high-energy astrophysical tau neutrinos late last year. There was this exquisite measurement of the cosmic ray anisotropy by IceTop and HAWC. And the Glashow event, being able to finally publish that and make it public, that was a highlight.
We keep just pushing the frontier of what this instrument can do. The calibration work over the last two years has been really impressive — the knowledge of the ice, the knowledge of the detector itself — which allows us to keep extracting better quality science. Every year, it’s always a surprise. If you look back at some of the studies of projections for how this instrument would perform, we’ve far exceeded them. We clearly haven’t reached the limit of what this instrument can do.
Ignacio Taboada: The detector performance is improving dramatically, and it’s not simply because we’re accumulating more data. If you have a study of two years of data and then you publish a new one with five years of data, it will be better simply because there is more data. IceCube, as a 10-year-old detector, is benefiting from that, but we are publishing results that very often are far better than simply accumulating more data. They actually reflect a better understanding of the instrument and reflect a better understanding of the ice.
The past two years have also seen a dramatic increase in the use of machine learning within the collaboration, and that has had a dramatic impact on the scientific output of IceCube. Machine learning in the broadest sense of the word has been used in IceCube for ages. Boosted decision trees, for example, are normally considered machine learning, and they have been used in IceCube for at least 15 years. But with deep neural networks that only modern computing enable, especially with GPUs, it’s really the past two years that have seen dramatic increase. One specific analysis that has benefited enormously from that is the cascade analysis, where we have improved the ability to determine the direction of cascades enormously. At some energies, it is more than a factor of two — it’s really impressive. These neural networks are having an impact in other areas as well.
The pandemic upended the world in 2020, presenting some unique challenges for Antarctic research and IceCube on both the micro and macro levels. Darren, how has the collaboration handled the last year? Ignacio, how will the effects of the pandemic influence how you lead going forward?
DG: There was no one left untouched by this pandemic, that is absolutely clear. The collaboration has persevered. It has not been easy; the way that we generally operate had to shift pretty dramatically. And the inability to meet in person...that impact, it’s hard to quantify overall. But I have just seen the collaboration rally and really come together as a team.
In terms of the operations, in terms of the scientific output, pursuing our mission, it is incredibly challenging but it’s working. It is so far from ideal, but the papers are excellent, the community is responding, we continue to produce science that is world-class and is recognized globally. The fact that we’ve been able to continue to do that is a testament to the team, to the entire collaboration broadly.
IT: I think every crisis is an opportunity. I am sure that there are a gazillion ways in which we all hate the way we’re operating right now. However, it is a good time to look at the way we operate and consider the norms we had before, and among all the disaster of having to work through Covid restrictions, what are the things that we want to keep? My hope is that the collaboration actually works better as a collaboration after we’re able to meet again in person. For example, should the collaboration meetings have the same format they had in the past? I think they shouldn’t, I think they should adapt. We can learn from the forced-online collaboration meetings to see what is it that we want to change for future collaboration meetings.
In 2019, NSF awarded IceCube funding for the IceCube Upgrade. How are those efforts going? How do you see them moving forward in the next two years?
DG: The Upgrade is going really, really well. Progress has been absolutely fantastic in spite of all of the best efforts of the pandemic to throw wrenches into this. The status that we have seen and the updates during the meetings last week...it is incredible! The modules in Japan are on schedule; they’re going to be ready for shipping this year. The first modules in Germany have been assembled and they’re on track for their design verification tests. The pandemic has introduced really unique challenges for the upgrade, and we are having to reevaluate the schedule — that is unavoidable. But, again, it’s a testament to what this collaboration can accomplish as a team when they work together that we are where we are.
IT: I was really impressed with some of the testing of the multiple-PMT DOMs that is being conducted right now. It is really beautiful, and it reminds me of the effervescence that IceCube had when IceCube itself was being built. Those were really exciting times and it’s really cool to see this happening again in very similar ways in spite of the circumstances.
What about the next planned extension, IceCube-Gen2?
DG: The progress there is really another highlight of the last two years. We started talking about Gen2 back in 2014. It’s been incredible to watch that evolve over that period of time, but things have accelerated in the last two years. The vision for Gen2 has started to materialize in this period. In particular, in the last year, we published the white paper, which was an enormous effort by the collaboration and such an incredibly important exercise because all of the ideas that had been forming up until that point basically got shaken out, and the collaboration started to put together a vision and discuss that in the public forum. You can start to see that it’s within reach, the ideas that could bring Gen2 to reality.
IT: I am very hopeful about its future because it shares something with IceCube, which is a very wide breadth of scientific objective. IceCube was initially conceived to study astrophysical neutrinos and to search for the sources of astrophysical neutrinos. However, the amount of science that it can do in other areas — glaciology, cosmic rays, PeV gamma ray sources, searches for dark matter, etc. — that enormous scientific breadth is what has allowed IceCube to produce really good scientific results for a decade or longer. Because Gen2 is standing on similar premises, I think it has a really bright future.
Would either of you be willing to guess what IceCube’s next big scientific contribution or “breakthrough” will be?
DG: I would really love to see neutrinos in coincidence with a gravitational wave event. In terms of big breakthroughs, that in my mind would be one.
IT: What would be the absolute best possible news for IceCube? I think it would be a galactic supernova. That would be — I am serious — the scientific event of the decade. I’m not exaggerating. Now, is that going to happen over the next two years? Probably not. I mean, we get one every 50 years, maybe. But who knows?
Let me take a gamble on what I think would be something really interesting that may happen in the next two years. IceCube has been improving its data analysis methods significantly, and we will have more data. These two things combined mean that we’re beginning to get close to measuring neutrinos from our own galaxy, the galactic plane, and that will be a really beautiful result. We believe our astrophysical neutrinos are extragalactic [they come from outside our galaxy], but I think we may be close to seeing the galaxy as a whole, maybe. That’s a long shot, but not impossible.
What do each of you see as the key areas of growth for the collaboration moving forward?
IT: This is on my theme of the detector performing better than expected by just accumulating more data — that it will continue to happen. There are some groups within IceCube that are very organized on that front, but you’re seeing that as a sea of change it is going to take over the entire collaboration. So far, it has been very bottoms-up, but I think that it’s time to do a top-down counterpart as well.
DG: One of the areas that we have been working very hard in as a collaboration has been improvements for diversity, equity, and inclusion. This is an effort that is just so essential — not just for IceCube, but also for science and for society in general. I think that we will continue to see that effort really grow and mature over the next few years, in particular. I am incredibly encouraged by the people that we have in the collaboration who really care and invest their time and efforts in these areas. Being able to be a part of that has just been an incredible experience. I hope that, as I move forward, it is something that I can continue to contribute to.
Ignacio, why did you decide to run for spokesperson? What are your main goals for the coming two years?
IT: I had not considered being a spokesperson until pretty much the last second. I was nominated and then asked if I wanted to be considered. I had not really considered that as an option for now — maybe it’s something that would have occurred to me on my own, years from now, but not now. I thought about it and I didn’t sleep for a couple of nights because I know that it is a gigantic responsibility.
But I decided that I can help the IceCube Collaboration. I also really hope that I can play a role in a future unification of IceCube and IceCube-Gen2. Whether the actual formation of an IceCube-Gen2 collaboration, with funding and all, happens in the next two years, I cannot tell. But that is definitely high on my list of goals.
The other thing that I have on my list of goals is — and this matters to me very much — that I want to make every IceCube member feel welcome within IceCube. There are 350 authors whose names go into papers, but we have other people that don’t have their names going into papers, and I want to make sure that everybody that is related to IceCube in one way or another feels welcome within IceCube. I mean that in the broadest sense possible. I began doing this when the collaboration (back then, the AMANDA collaboration, the predecessor of IceCube) was maybe 25 people, and I knew everybody by name and everybody knew me. And now that it’s a gigantic enterprise, it is very easy, for example, for new PhD students to feel intimidated by professors, the analysis coordinator, the spokesperson. That’s not what I want — what I want is for everybody to feel welcome, because every single one of these people has tremendous potential to contribute to the experiment.
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College of Sciences at Georgia Tech
Renay San Miguel
Communications Officer II/Science Writer
College of Sciences at Georgia Tech
University of Wisconsin-Madison IceCube Particle Astrophysics Center