West Mountain Observatory contributes to understand distant galaxy

West Mountain observatory
West Mountain Observatory at sunset.

A team of 86 scientists from 13 countries recently carried out extensive high-time resolution optical monitoring of a distant active galaxy, BL Lacertae (BL Lac). Mike Joner, BYU research professor of physics and astronomy, was one of the astronomers contributing to the project.

Dr. Joner and BYU undergraduate student Gilvan Apolonio secured over 200 observations of the galaxy using the 0.9-meter reflecting telescope at the BYU West Mountain Observatory. Their measurements were combined with observations made by other scientists around the world in a collaboration known as the Whole Earth Blazar Telescope (WEBT). The WEBT network makes it possible to monitor objects around the clock from different locations during times of high variability.

Using the WEBT observations made in the summer of 2020, astronomers discovered surprisingly rapid oscillations of brightness in the central jet of the galaxy BL Lac. The scientists attribute these cycles of brightness change to twists in the jet’s magnetic field. Their study was recently published in the scientific journal Nature.

BYU’s West Mountain Observatory was one of 37 ground-based telescopes throughout the world monitoring the optical variations of BL Lac – an active galaxy classified as a blazar that is roughly 1 billion light years away. Joner and Apolonio alternated working different groups of nights at the observatory throughout the spring and summer of 2020 – a task that was extra burdensome during the height of the pandemic. This atypical work schedule was necessary since observations were needed on every clear night and there were no other trained student observers remaining in the Provo area.

An analysis of the high-cadence optical observations was critical to understanding the high-energy observations from the space-based Fermi Gamma-Ray Telescope.

“You need to combine data from high-energy space observatories with optical ground-based monitoring data. The billion-dollar space telescopes that are used on projects like this often need to compare results with optical ground-based observations,” said Joner. “Correlating what was seen in the high energy observations with the ground-based light curves helped confirm the rapid periodic oscillations that were observed in the high-energy data from space.”

Although he’s an established expert in astrophysical research, Joner says he continues to be amazed at the level of detail scientists are capturing through such observations. And he’s grateful for the chance to explore the far reaches of the cosmos with his students at BYU.

“On a galactic scale, the central jet of a blazar is quite small. It is amazing to be able to see the variations of the jet so clearly. The variability of the jet is easily seen even though it is combined with the light from the hundreds of billions of stars in the host galaxy,” he said.

“It is noteworthy that in this age of giant telescopes and space-based research, it is still necessary to rely on modest sized and well-equipped facilities like we have available at BYU to explore the unknown reaches of the Universe.”

Boston University doctoral student Melissa Hallum, a BYU graduate and former student of Dr. Joner’s, was also a co-author of the paper.

More Information on This Article

Article Source/Further Information

News and Events

Image for Wesley Morgan Doubles AP Physics Enrollment
Y Magazine recognizes finalist for the 2023 National Science Foundation’s Presidential Award of Excellence in Mathematics and Science Teaching
Image for BYU Women in Physics Students Thrive at CUWiP
Conference for Undergraduate Women in Physics provides support and opportunities for female BYU physics students
Image for New Faculty Member, Dr. Micah Shepherd
Dr. Micah Shepherd, Acoustic Physicist, joins faculty
Image for Nanoparticle Drug Delivery Using Magnetism
Dr. Karine Chesnel awarded Interdisciplinary Research Origination Grant
Image for Sommerfeldts Called as Mission Leaders
Professor Scott and Lisa Sommerfeldt in Missouri Independence Mission
Image for Adam Fennimore's Insights for Students
Alumni Adam Fennimore shares career insights for current students
Image for Society of Physics Students Awarded Outreach Grant
BYU's SPS is selected for Marsh Award for their outreach plan with Boys & Girls Club
Image for Rocket Noise and Bird Songs
Hart, Gee, and their research group study the impact of rocket noise on wildlife
Image for Dr. Ragozzine's Nice, France Obersvatoire Sabbatical
Darin Ragozzine collaborates with leading planetary scientists in France
Image for New Faculty Member, Dr. Greg Francis
Dr. Greg Francis joins faculty, specializing in Physics Education
Image for Steve Summers' Insights for Students
Alumni Steve Summers answers interview questions for current students