Jason Dexter

Trying to Solve a Key Black Hole Mystery: Simulating Magnetic Flows Around Black Holes

Steven Burrows — Tue, 18 Feb 2025 19:48:01 +0000

Trying to Solve a Key Black Hole Mystery: Simulating Magnetic Flows Around Black Holes Steven Burrows Tue, 02/18/2025 - 12:48

Kenna Hughes-Castleberry / JILA Science Communicator

Black holes have been fascinating subjects of study, not just because they are cosmic vacuum cleaners, but also as engines of immense power capable of extracting and redistributing energy on a staggering scale. These dark giants are often surrounded by swirling disks of gas and dust, known as accretion disks. When these disks are strongly magnetized, they can act like galactic power plants, extracting energy from the black hole’s spin in a process known as the Blandford-Znajek (BZ) effect.

While scientists have theorized that the BZ effect is the primary mechanism in the energy extraction process, many unknowns remain, like what determines how much energy is funneled into powerful jets—powerful streams of particles and energy ejected along the black hole's poles—or dissipated as heat.

To answer these questions, JILA postdoctoral researcher Prasun Dhang, and JILA Fellows and University of Colorado Boulder Astrophysical and Planetary Sciences professors Mitch Begelman and Jason Dexter, turned to advanced computer simulations. By modeling black holes surrounded by thin, highly magnetized accretion disks, they sought to uncover the underlying physics that drives these enigmatic systems. Their findings, published in The Astrophysical Journal, offer crucial insights into the complex physics around black holes and could redefine how we understand their role in shaping galaxies.

“It's long been known that infalling gas can extract spin energy from a black hole,” elaborates Dexter. “Usually, we assume this is important for powering jets. By making more precise measurements, Prasun has shown there's a lot more energy extracted than previously known. This energy could be radiated away as light, or it could cause gas to flow outwards. Either way, extracted spin energy could be an important energy source for lighting up the regions near the black hole event horizon.”

Comparing Black Hole to Black Hole

For decades, scientists have studied black holes and their interactions with surrounding gas and magnetic fields to understand how they power some of the universe’s most energetic phenomena. Early research focused primarily on low-luminosity black hole sources with quasi-spherical accretion flow as these systems are comparatively easier to simulate and align with many observed jets.

However, high-luminosity black holes with geometrically thinner, denser magnetized disks present a unique challenge. These systems are theoretically unstable due to imbalances in heating and cooling.

Artist render of a black hole surrounded by a highly magnetized thin disk. Image credit: Steven Burrows / JILA

However, previous studies, including those by Mitch Begelman, suggested that strong magnetic fields might stabilize these thin disks, but the details of their role in energy extraction and jet formation remained unclear in such conditions.

“We wanted to understand how energy extraction works in these highly magnetized environments,” Dhang explains.

Simulating Magnetized Flows Around Black Holes

The team used advanced computer simulations to explore this phenomenon, specifically, a special type of model called the 3D general relativistic magnetohydrodynamic (GRMHD) model. The GRMHD model works as a computational framework that simulates the behavior of magnetized plasma in the curved spacetime around black holes, combining the physics of magnetic fields, fluid dynamics, and Einstein's theory of general relativity to capture the complex interactions in these extreme environments. Using the framework, the researchers observed how magnetic fields interacted with black holes spinning at different speeds.

“The goal was to see how magnetic flux threading [permeating] the black hole impacts energy extraction and whether it leads to the formation of jets,” Dhang says.
The simulations modeled thin, magnetized accretion disks and examined how much energy the black hole transferred to its surroundings. By studying the efficiency of this energy extraction, the team identified various black hole spins and magnetic configurations with jets.

Manifestation of BZ power

From their simulations, the team found that depending on the black hole's spin, between 10% and 70% of the energy extracted through the BZ process was channeled into jets.

“The higher the spin, the more energy the black hole can release,” Dhang notes.

However, not all energy went into jets; some was absorbed back into the disk or dissipated as heat.

While the simulations couldn’t determine where the excess energy went, Dhang plans to study this further to better understand how jets form, as jets are often found in active galactic nuclei systems such as quasars.

Mysteries Continue

From their models, the researchers found that the strong magnetic fields increased the disk's radiative efficiency, making it brighter. This extra luminosity may explain why some black holes appear far more luminous than theoretical models predict.
“The unused energy close to the black hole could heat the disk and contribute to a corona,” Dhang notes.

The corona, a region of hot gas surrounding the black hole that emits intense x-rays, is crucial for shaping the light we observe from these systems, but its exact formation process remains unclear.

The researchers hope to use further simulations to understand the dynamics of making a black hole corona.

This work was supported by the National Science Foundation, the NASA Astrophysics Theory Program, and the Alfred P. Sloan Fellowship.

JILA postdoctoral researcher Prasun Dhang, and JILA Fellows and University of Colorado Boulder Astrophysical and Planetary Sciences professors Mitch Begelman and Jason Dexter, turned to advanced computer simulations to model black holes surrounded by thin, highly magnetized accretion disks, to uncover the underlying physics that drives these enigmatic systems. Their findings, published in The Astrophysical Journal, offer crucial insights into the complex physics around black holes and could redefine how we understand their role in shaping galaxies.

Off

Traditional

White

JILA Undergraduate Research Assistant Aaron Barrios is Awarded a 2024 Jacob Van Ek Scholarship

Steven Burrows — Fri, 19 Apr 2024 17:34:07 +0000

JILA Undergraduate Research Assistant Aaron Barrios is Awarded a 2024 Jacob Van Ek Scholarship Steven Burrows Fri, 04/19/2024 - 11:34

Kenna Hughes-Castleberry / JILA Science Communicator

Undergraduate research assistant Aaron Barrios

JILA undergraduate student Aaron Barrios has recently been honored with the prestigious Jacob Van Ek Scholarship, an accolade from the University of Colorado Boulder College of Arts and Sciences to a select group of exceptional undergraduates. This year, Barrios is among 23 distinguished students to receive one of the college's highest honors, reflecting his outstanding contributions and academic excellence in Physics, Astronomy, and Mathematics.

The scholarship is named after Jacob Van Ek, who profoundly impacted CU’s academic landscape. Van Ek, born in 1896, began his illustrious career at CU shortly after completing his doctorate in 1925 at what is now Iowa State University. He quickly ascended from an assistant professor to a full professor within a mere three years and served as the dean of the College of Liberal Arts from 1929 to 1959. His legacy continues to inspire and recognize student excellence through this scholarship.

Aaron Barrios's research, under the mentorship of JILA Fellow and Astrophysical & Planetary Sciences professor Jason Dexter, focuses on the intriguing dynamics of black holes and accretion disk theory. Barrios' work primarily investigates how isotropic emissions around black holes can become anisotropic, a critical study in understanding the behavior of light and radiation in extreme gravitational fields.

JILA undergraduate student Aaron Barrios has recently been honored with the prestigious Jacob Van Ek Scholarship, an accolade conferred by the University of Colorado Boulder College of Arts and Sciences to a select group of exceptional undergraduates. This year, Barrios is among 23 distinguished students to receive one of the college's highest honors, reflecting his outstanding contributions and academic excellence in the fields of Physics, Astronomy, and Mathematics.

Off

Traditional

White

Questions about Quasars: How to Best Weigh a Celestial Body

Steven Burrows — Fri, 18 Aug 2023 17:24:49 +0000

Questions about Quasars: How to Best Weigh a Celestial Body Steven Burrows Fri, 08/18/2023 - 11:24

Kenna Hughes-Castleberry / JILA Science Communicator

A comparison of two theoretical models, the cloud and the disk wind model. Image credit: Steven Burrows / JILA

In a new paper in The Astrophysical Journal, JILA Fellow Jason Dexter, graduate student Kirk Long, and other collaborators compared two main theoretical models for emission data for a specific quasar, 3C 273. Using these theoretical models, astrophysicists like Dexter can better understand how these quasars form and change over time.

Quasars, or active galactic nuclei (AGN), are believed to be powered by supermassive black holes at their centers. Among the brightest objects in the universe, quasars emit a brilliant array of light across the electromagnetic spectrum. This emission carries vital information about the nature of the black hole and surrounding regions, providing clues that astrophysicists can exploit to better understand the black hole's dynamics.

A Tale of Two Models

Light emission from a quasar gives astrophysicists many insights into the mechanics of the supermassive black hole. For Dexter and Long, the emission data from quasar 3C 273 came from GRAVITY, an instrument on Chile’s VLT (Very Large Telescope). “Specifically, we used near-infrared light (too red for your eyes to see but still close enough to the visible spectrum that a ‘normal’ telescope mirror reflects it) to look at quasar 3C 273 in this work, as the emission line we care about emits in this wavelength regime,” explained Long.

Per previous findings, Long and Dexter expected the GRAVITY emission data to reveal one peak for quasar 3C 273. While this single peak is a hallmark of quasar emission spectra, the mechanism that produces it is still up for debate, as some people believe that this comes from the emission falling into the black hole and swirling within the galactic whirlpool.

“But how far does this geometry extend?” asked Long. “If you were to think about this area where these emission lines come from—which we call the broad-line region—if you imagine that as a spinning disk emitting isotropically, where every part of the disk is glowing at the same temperature, you would expect to see two emission peaks.”

This is because one peak is red-shifted toward the viewer and one blue-shifted away from the viewer due to the Doppler effect.

However, as seen in the data from quasar 3C 273 (and many other quasars), there aren't two peaks but just one. This means that the emission from the quasar is not following the simplest model, and something more complicated is happening. Astrophysicists apply various models to their data to examine the mechanisms causing the one emission peak.

To better understand the data variations, Dexter and Long looked at the two main theoretical models proposed as possible underlying mechanisms: the cloud and disk-wind models. For Dexter, comparing these two models could offer more insight into the modeling process itself.

“One of the important takeaways from this is that you can actually measure the uncertainty in the mass of the black hole to quantify how wrong you are if you have the wrong model,” he added. “In this particular case, we can also check consistency because we know how we look at this black hole from other data. The view that [a] particular model [may pick may] not match the other data. So we can say that that's probably a disfavored solution. It’s important for future work to keep in mind that the model you choose impacts the measurements you get. So, we aren't going to know how we're looking at these systems in general, which means it's important to try to figure out which of these models holds water in the biggest number of cases.”

The cloud model proposes that the emission lines observed in quasar spectra arise from clouds of ionized gas near the central black hole. Long elaborated: “There are basically a bunch of clouds chaotically spinning around the black hole. Those clouds make the single peak because you've filled in more of a spherical type geometry instead of just a disk, like a star. So, you can get one peak because most of the emitting gas isn’t moving towards or away from you. The clouds are on weird tilted orbits but still in stable orbits so you can weigh the black hole.”

While the cloud model fits several quasar data sets, the mechanics don’t seem to add up. “There's this mystery that you assume that the clouds should be falling in and swirling around in this disk,” Dexter stated. “But, if this process produces atomic gas transitions, it should produce these two peaks where you see lines. But that's not what we see; it’s always the single peak.” To explain this difference, several astrophysicists theorize that the atomic gases have puffed up, causing a change in the emission spectra.

To address the disparity between the one and two peak emissions, other astrophysicists proposed a different model called the disk-wind model. This model suggests that the observed quasar emissions “come from the footprints of winds embedded in the disk,” Long explained. “In this model, you can still have a thin disk all the way out to the broad-line region, but now your extra assumption is that you will add shears to the disk. In our study, we added a couple of different shears because we see observational evidence for outflows and inflows, where gases are being blown away or blown in from this region.”

Comparing Models and Data

Using the University of Colorado Boulder’s supercomputing system, Dexter and Long applied the disk-wind model to the quasar 3C 273 data set to see how well it fit. From their computations, Dexter and Long found that the disk-wind model would indeed change the calculated amount for black hole mass by a factor of 5.

But the disk-wind model had more uncertainties than the cloud model, which Dexter previously analyzed. “I think, while we disfavored the disk-wind model based on our results, the only reason we can disfavor it for quasar 3C 273 is not that it actually fits the data that much worse—it actually fits the data about as well as the cloud model—it's that it requires you to be looking at the disk in a different way than the way you would be looking at the clouds,” Long explained.

By fitting the disk-wind model to the data, Long and Dexter had to reorient their view of 3C 273 and look at it sideways. “That tells us that maybe this version of our proposed model is wrong,” added Long. “But there may be other things we could add to the disk-wind model that could better align it to the jet, so we don’t rule it out completely.”

From their results, Dexter and Long can better understand how these uncertainties may affect the larger process of “weighing” supermassive black holes, which can be leveraged by other astrophysicists when looking further into the dynamics of quasars.

In a new paper in The Astrophysical Journal, JILA Fellow Jason Dexter, graduate student Kirk Long, and other collaborators compared two main theoretical models for emission data for a specific quasar, 3C 273. Using these theoretical models, astrophysicists like Dexter can better understand how these quasars form and change over time.

Off

Traditional

White

JILA Graduate Students Tyler McMaken and Lia Hankla Awarded the 2022 Richard Nelson Thomas Award

Steven Burrows — Wed, 01 Jun 2022 19:52:06 +0000

JILA Graduate Students Tyler McMaken and Lia Hankla Awarded the 2022 Richard Nelson Thomas Award Steven Burrows Wed, 06/01/2022 - 13:52

Kenna Hughes-Castleberry / JILA Science Communicator

Tyler McMaken (left) and Lia Hankla (right) were awarded the 2022 Richard Thomas Nelson award

Two JILA graduate students were awarded this year's Richard Nelson Thomas Award for Graduate Students in Astrophyiscs. This award is given annually in honor of Dr. Richard Nelson Thomas, a founding member of JILA and an astrophysics researcher. Dr. Thomas was instrumental in establishing JILA's Visiting Fellows program, as well as growing the institution as a whole. Because of Dr. Thomas' legacy, his family and friends established an annual award given to an outstanding graduate student in astrophysics.

This year, graduate students Tyler McMaken and Lia Hankla received the award. McMaken studies under JILA Fellow Andrew Hamilton, and focuses on black hole dynamics, looking at how quantum field theory and general relativity work in tandem on this phenomena in the galaxy. Similarly, Hankla also studies black holes under JILA Fellow Jason Dexter. Her research focuses on plasma (hot gas) interacting with the black holes. Both graduate students will receive $1000 as part of the award. These students were nominated by several JILA faculty members in order to recognize their hard work and dedication to their field.

Off

Traditional

White

The Mystery of Black Hole Flares

Steven Burrows — Tue, 19 Oct 2021 18:21:31 +0000

The Mystery of Black Hole Flares Steven Burrows Tue, 10/19/2021 - 12:21

Kenna Hughes-Castleberry / JILA Science Communicator

A model of black hole flares. Image credit: Steven Burrows / JILA

In 2019, a team of researchers used an international network of radio telescopes—called the Event Horizon Telescope—to take the first photo of a supermassive black hole in the center of the elliptical galaxy Messier 87 (M87). On that team of researchers was JILA Fellow Jason Dexter. Since then, Dexter has been studying M87's black hole further using simulations, with code written by researchers at the University of Illinois. As described in a new paper published in the Monthly Notices of the Royal Astronomical Society (MNRAS), Dexter, and his team of graduate students and postdoctoral researchers, collaborated with researchers at the Los Alamos National Laboratory and the University of Illinois to create a new simulation studying the edge of a black hole.

The researchers specifically focused on the phenomenon of flaring that occurs around the black hole. Flares, also called jets, are outputs of hot gas. The source of these flares and the explanations for their behavior are still unknown. These unanswered questions intrigued first author Philippe Z. Yao, who led this study as a ��Ҵ�ý�ƽ�� undergraduate student. “I started talking to Jason Dexter about what we can do to help us better understand the processes around black holes. And since we also see these very high-energy flares that come from M87, we do not know what processes really trigger them,”said Yao. Dexter echoed this uncertainty about where the flares around the black hole occur: “The brightness changes can occur in about the same amount of time it would take for light to cross roughly the size of the event horizon of the black hole. So, it's possible that the flares happen close to the black hole.” The event horizon is the term for the edge of the black hole. The telescope images that showed the flares were confusing to the researchers, as the flares could have been either close to the event horizon, or farther away, just flaring at a faster rate.

In order to better understand where these flares were occurring, the researchers created General Relativistic Magneto-Hydro-Dynamic (GRMHD) simulations, which naturally follow how gas flows along magnetic fields that thread through a black hole. The GRMHD simulations looked at accretion flow of the gas, where the gas spinning around the black hole slowly moves toward the black hole, and eventually falls in. Dexter explained this accretion flow in the simulation by describing the gas as: “an ionized fluid made of protons and electrons. The reason the gas falls into the black hole is that the charged particles conduct magnetic fields and the magnetic fields actually cause the gas to become unstable and turbulent. The turbulence causes collisions which knock the gas off of stable orbits around the black hole and cause it to fall in through the event horizon. And the magnetic fields also end up launching the jet that we see.” In studying how the gas moves toward the event horizon of the black hole, the researchers hoped to find an explanation for the cause of the flares as well as their positions relative to the black hole.

Gas and Light

The simulation not only modeled the flow of this gas, but also how it interacted with light particles, called photons. According to Dexter, the gas cools by radiating light and gamma rays. “The gas heats up, and then we can track its cooling,” Dexter said. “That puts us in a unique position, because all the mechanisms for how you might produce flares close to the black hole rely on how photons interact with matter. We're able to realize what we think is a physically realistic description of the gas and the photons near the black hole.” The study of the photons in the gas shed new light (no pun intended) on more processes occurring at the edge of a black hole.

This simulation is also important because it builds on previous black hole research. “Previous work on the flares have made simplifying assumptions about the low-energy photons near the black hole,” said postdoctoral researcher Alexander Chen, who had worked on flare models before this paper. “One of the results of this work is that we have a much better understanding of how these low-energy photons are distributed.” The team is planning to continue building on these simulations to find ways to answer questions about the black hole flares. “Our calculations provide new background conditions for calculations of the flaring process itself,” Dexter stated. “What we find is that how the light is moving inside the jet is not at all uniform, with photons moving mostly inwards close to the black hole and away from it as well.” Chen, for his part, is excited to continue the research: “We can now take this result and compute more accurately the gamma-ray flares, and compare with data. This is what we're going to do next.”

In 2019, a team of researchers used an international network of radio telescopes—called the Event Horizon Telescope—to take the first photo of a supermassive black hole in the center of the elliptical galaxy Messier 87 (M87). On that team of researchers was JILA Fellow Jason Dexter. Since then, Dexter has been studying M87's black hole further using simulations, with code written by researchers at the University of Illinois. As described in a new paper published in the Monthly Notices of the Royal Astronomical Society (MNRAS), Dexter, and his team of graduate students and postdoctoral researchers, collaborated with researchers at the Los Alamos National Laboratory and the University of Illinois to create a new simulation studying the edge of a black hole.

Off

Traditional

White

Scientists Dig Deeper into Subject of First-Ever Image of a Black Hole

Steven Burrows — Mon, 10 May 2021 19:06:59 +0000

Scientists Dig Deeper into Subject of First-Ever Image of a Black Hole Steven Burrows Mon, 05/10/2021 - 13:06

Daniel Strain / ��Ҵ�ý�ƽ�� Strategic Communications

Image of a black hole. Image Credit: EHT Collaboration

An international team of scientists, including a University of Colorado Boulder researcher, has taken the most detailed look yet at the supermassive black hole at the center of a galaxy called Messier 87. The results suggest the celestial object is surrounded by strong magnetic fields—key ingredients that could help generate galaxy-length jets of particles that shoot out around it.

The research, published in two studies on 24 March, 2021, in The Astrophysical Journal Letters, is the latest to emerge from the Event Horizon Telescope, a collaboration that includes more than 300 scientists from five continents drawing on observations from several telescopes around the world.

In April 2019, the team made international headlines when it released the first-ever image of the immediate vicinity of a black hole. That now-famous portrait of this object shows a dark shadow the size of our entire solar system ringed by a swirling mass of ultra-hot, magnetized plasma called an “accretion disk.”

��Ҵ�ý�ƽ�� astrophysicist Jason Dexter is a member of the Event Horizon Telescope collaboration and coordinating author of one of the new papers. He said that the 2019 image finally gave a face to black holes. But for scientists like him who want to understand how the bodies behave, it was just the beginning.

“I think these new papers are going to be a major step forward in using Event Horizon Telescope data to look at how black holes grow,” said Dexter, a JILA fellow and assistant professor in the Department of Astrophysical and Planetary Sciences.

The team’s latest images look at the same black hole, but in polarized light. That’s a term researchers use to describe the orientation of light waves as they travel through space. (Polarized sunglasses work by blocking light with certain orientations, while allowing other light through). Such data, Dexter said, may help scientists to dive deep into the belly of a black hole.

“We’re seeing strong magnetic fields near the black hole,” he said. “These fields may be able to extract energy from the black hole itself and use it to power these jets.”

Rings of fire

That hot and volatile environment is Dexter’s specialty.

He explained that the tricky thing about studying objects like M87*, the black hole at the center of M87 more than 50 million light-years from Earth, is that they’re impossible to see on their own. The gravity produced by black holes is so strong that even light can’t escape their grasp if it gets too close.

But scientists can view the area just outside of a black hole and, in particular, its accretion disk. As Dexter put it: “We can’t see inside a black hole, but we can study what’s all around it.”

There’s a lot to study: Accretion disks form when massive central objects gobble down humungous clouds of gas from the surrounding space. Like water circling a bathtub drain, that material will begin to spin around the black hole the nearer it gets. Scientists have long suspected that this churning matter could, under the right circumstances, generate magnetic fields—similar to what makes the field that causes compasses point north on Earth.

“We have two broad theories for what those magnetic fields can look like,” Dexter said. “Some research has suggested that they could be weak and are simply dragged along with the gas. The other idea is that they can become really strong near the black hole and actually push back against that motion.”

To probe the nature of those fields, the Event Horizon Telescope group combined data collected from telescopes spread across our own planet. That information allowed the team to measure the polarization of light from M87’s accretion disk, which, in turn, holds clues to the churning dynamics below.

The group’s results suggest that the black hole’s magnetic fields are anything but weak.

“They’re not being dragged around passively with the gas,” Dexter said. “They’re strong, and that can change the entire structure of how gas is falling into the black hole, and even how this black hole is growing over time.”

Bright jets

Just what that means for the black hole isn’t clear yet.

Dexter, however, believes that strong magnetic fields could be the key to understanding M87’s explosive nature. Scientists have previously observed a humungous “jet” of gas that seems to blast off from around the black hole and stretch for potentially tens-to-hundreds of thousands of light-years. According to theory, the rotation of a black hole itself may twist up the magnetic fields in an accretion disk, generating built up energy that can occasionally burst out to form jets.

“The Event Horizon Telescope gives us the ability to study these processes where they’re really important—where energy is being released and where jets are being launched,” Dexter said.

For now, he’s excited that the data coming from the study has, at least so far, matched the theory. Put differently, the images of M87 to date look a lot like what researchers expected them to—something Dexter finds comforting.

“To me, that’s evidence that we’re on the right track,” he said. “We seem to understand the basic physics of accretion disks and how these black holes grow, which to me is amazing.”

Off

Traditional

White

Jason Dexter Looks Deeper Into the First Image of a Black Hole

Steven Burrows — Wed, 24 Mar 2021 20:46:41 +0000

Jason Dexter Looks Deeper Into the First Image of a Black Hole Steven Burrows Wed, 03/24/2021 - 14:46

Kenna Hughes-Castleberry / JILA Science Communicator

Image of the first black hole pictured

A new paper in the Astrophysical Journal Letters tells the new and ongoing research done by the team working with the Event Horizon Telescope looking at the first ever photograph taken of a black hole. This photograph won the team an award two years ago. JILA Fellow and assistant professor in the Department of Astrophysical and Planetary Sciences, Jason Dexter, is a coordinating author on this paper, and is excited by the current research. According to an article written by science writer Dan Strain, Dexter said: "I think these new papers are going to be a major step forward in major step forward in using Event Horizon Telescope data to look at how black holes grow."

You can read the full article about the new research here at ��Ҵ�ý�ƽ�� Today.

In a team of over 300 scientists, JILA Fellow and assistant professor in the Department of Astrophysical and Planetary Sciences, Jason Dexter digs further into the first picture ever taken of a black hole. His research has been recently published in a new paper for the Astrophysical Journal Letters.

Off

Traditional

White

JILA Fellow Jason Dexter Wins 2020 Sloan Fellowship

Steven Burrows — Thu, 13 Feb 2020 02:13:50 +0000

JILA Fellow Jason Dexter Wins 2020 Sloan Fellowship Steven Burrows Wed, 02/12/2020 - 19:13

Rebecca Jacobson / JILA Science Communicator

The Alfred P. Sloan Foundation announced on February 12 that JILA Fellow Jason Dexter has won a 2020 Sloan Fellowship.

Dexter joined JILA in 2019. Dexter’s work revolves around black holes, specifically how gas falls into black holes and their use as probes of strong gravity. He is a core member of the Event Horizon Telescope Collaboration, which captured the first image of a black hole last year.

“I’m honored to receive this prestigious award," Dexter said. "Images and movies of gas falling into black holes hold tremendous promise for learning how they grow and for understanding their nature. The Sloan Fellowship will support our group’s work in maximizing the science return on these breakthrough observations using state of the art computational models."

The Sloan Fellowships recognize 126 early career researchers who have the potential to revolutionize their fields. These two-year fellowships are granted across the sciences, including chemistry, computer science, economics, mathematics, molecular biology, neuroscience, ocean sciences, and physics. Each 2020 fellow receives $75,000 for his or her fellowship.

JILA Fellow Jason Dexter has been selected for a 2020 Sloan Fellowship.

Off

Traditional

White

Jason Dexter, JILA’s newest fellow, wins Breakthrough Prize

Steven Burrows — Sat, 07 Sep 2019 01:19:17 +0000

Jason Dexter, JILA’s newest fellow, wins Breakthrough Prize Steven Burrows Fri, 09/06/2019 - 19:19

Rebecca Jacobson / JILA Science Communicator

The Breakthrough Prize is considered the highest-paying prize in science, with a total of $21.6 million for achievements in fundamental physics, mathematics and life sciences. On Thursday, JILA’s newest fellow Jason Dexter was one of 347 scientists to be honored with the Breakthrough Prize in Fundamental Physics for their work on the Event Horizon Telescope.

But don’t worry; he won’t be quitting his job at JILA any time soon. The $3 million prize for the team works out to about $8,600 per participant—so it might be enough to pay rent in Boulder, he joked.

Dexter worked on predictions on what the Event Horizon Telescope would see while he was doing his Ph.D. in Seattle. And his group’s prediction for M87, the black hole in the now famous image, was pretty close. Seeing the results come back from the experiment was incredible.

Prior to arriving in Boulder, Dexter was at the Max Planck Institute for Extraterrestrial Physics, where he was also involved in the GRAVITY project. But many of the American Physical Society experts on black holes are here at JILA, so Dexter chose to come here.

“It allows for a lot of lively discussions on black hole physics,” he added.

At JILA, Dexter is now building his research group, and continues to study images and videos of gas falling into black holes, and what that can tell us about how black holes work. As an astrophysicist, his work focuses on theory and interpretation around these observations—and seeing that image from the Event Horizon Telescope is just the start of new discoveries in physics, he added.

“Now that evidence comes down to the scale of the event horizon itself,” he said. “The best is yet to come.”

“It was amazing,” Dexter said. “For me, personally, it’s the coolest thing that I’ve seen in science.”

“It allows for a lot of lively discussions on black hole physics,” he added.

“Now that evidence comes down to the scale of the event horizon itself,” he said. “The best is yet to come.”

Dexter is one of the 347 scientists who worked on the Event Horizon Telescope.

Off

Traditional

White