Originally posted on Cal Poly by Nick Wilson.
SAN LUIS OBISPO — In the second year of the Astronomy Faculty Research Fellowship in Cal Poly’s Bailey College of Science and Mathematics, a research team will study extremely high-energy photons emitted by the extreme environment found near mega-sized black holes.
The fellowship program was launched in 2023 through a generous donation from the Marrujo Foundation, established by Daniel and Rosamaria Marrujo, covering three years of the program.
The fellowship reassigns faculty time to focus more closely with students on research, offering students cutting edge research-based experiences.
The 2024 faculty recipient, physics Professor Jodi Christiansen, is working with the VERITAS International Collaboration to study very-high-energy photons called gamma rays, that are emitted by particles shooting down the jets associated with supermassive black holes.
Black holes have powerful gravitational pull that sucks in just about anything in their proximity, light included, but some of that matter can also shoot out as jets of particles instead. The accretion disk (typically formed of gas, dust, asteroids and other matter) of diffuse material in orbital motion around massive central bodies remain outside of the black hole’s outer boundaries, and wouldn’t exist without the presence of black holes.
VERITAS — which stands for Very Energetic Radiation Imaging Telescope Array System — gathers data from the night sky using telescopes in southern Arizona at the Fred Lawrence Whipple Observatory. The observatory is located near Amado, Arizona on a summit at the foot of Mount Hopkins. Christiansen’s work has included trips to the telescope site in Arizona for research and viewing opportunities, as well as analyzing computer-based imaging remotely.
“These gamma rays are extremely energetic, so much so that they can’t come from a hot star, which just isn’t energetic enough,” Christiansen said. “What we’re looking at comes from the environment near a supermassive black hole.”
The plasma particles that the Cal Poly team observes come from an environment that is so powerful that the “atoms have fallen apart,” Christiansen said.
Most galaxies have a supermassive black hole at their center, Christiansen said, and some release energy in the form of enormous blasts of particle streams.
“Our images have shown jets that are bigger than galaxies,” Christiansen said. “This jet structure is huge compared to the galaxy. There aren’t a lot of places in space that produce this level of energy.”
Christiansen said that the high-energy gamma-rays that reach earth offer insights into the density and magnetic properties of the plasma very close to the supermassive black hole.
“There’s still a lot to learn about the physical mechanisms that produce the jets,” Christiansen said. “We don’t know why jets are formed. But we are very interested in how that energy can be released from this environment around the black hole.”
Christiansen’s Cal Poly research teams, in recent years, have been active in discovering blazars, which are streams of high-energy electromagnetic radiation that are directed at an angle that points toward the earth.
A few years ago, Christiansen developed a software algorithm for the VERITAS telescope that improves the resolution of the telescope by about 25% — and also allows scientists to detect signals with 30% less observing time, enhancing the ability to discover rare blazars and other astronomical phenomena.
The first year of the Marrujo fellowship was led by Elizabeth Jeffery, a Cal Poly assistant professor of physics, who explored data related to locations and brightness of stars to better understand how long they’ve existed. Jeffrey’s work focused on white dwarf stars, which represent the endpoint of a low mass star’s life.
The Marrujo Foundation supports and works with educational institutions to further research in astronomy, astrophysics and cosmology to establish a world-leading fellowship ecosystem. The foundation’s efforts aim to ensure that institutional work challenges current understanding of space, creates new opportunities and makes a difference in people’s lives across the U.S. and around the globe.
“The inaugural year of this program has been an amazing journey marked by success, profound insights, and captivating discoveries,” expressed Daniel Marrujo. “Dedicated to offering cutting-edge research and educational training to Cal Poly students, our commitment resonates with the essence of advancing the Learn by Doing mission and nurturing the future cohort of extraordinary astronomers and scientists. The Marrujo Foundation is filled with absolute delight as we witness the flourishing landscape of Cal Poly astronomy, and we eagerly anticipate the unfolding of remarkable accomplishments yet to come.”
Marrujo holds a master’s degree in materials engineering and a bachelor’s degree in electrical engineering with a minor in physics from Cal Poly. He is the former chief strategy officer and former director of the Office of Research and Technology Applications at the Defense Microelectronics Activity, delivering microelectronics solutions to the U.S. Department of Defense. Marrujo is the president and managing director at Sacramento-based Trusted Strategic Solutions, LLC, working with commercial, civil, and national security entities to provide the foresight and expertise that ensures safety, time savings, and financial protections.
