Chad Hanna, associate professor of physics and astronomy and astrophysics, has been selected as one of six Penn State faculty members to receive the 2021 Faculty Scholar Medals for Outstanding Achievement.
Established in 1980, the award recognizes scholarly or creative excellence represented by a single contribution or a series of contributions around a coherent theme. A committee of peers reviews nominations and selects candidates.
Nominators said Hanna is a growing leader in the field of gravitational wave physics and has an increasingly visible presence in the Laser-interferometry Gravitational Wave Observatory (LIGO) Scientific Collaboration. LIGO is responsible for numerous discoveries — particularly related to black holes — and has benefited from Hanna’s expertise.
At LIGO, Hanna developed data analysis pipelines responsible for crucial discoveries such as the gravitational waves generated by the merger of binary black holes and binary neutron stars. The team responsible for this discovery, observed in 2015 and announced by LIGO in 2016, was awarded the 2017 Nobel Prize in physics.
“The first direct detection of gravitational waves emitted by a binary black hole merger in 2015 was hailed as a watershed moment for the world of physics and astronomy,” a nominator said. “In the almost five years since that time, observations of binary black hole mergers by LIGO have laid to rest a number of longstanding fundamental questions about high-energy astrophysics and gravity, including: Do black holes form in binary systems? Can they merge in a Hubble time? Do binary black hole mergers seed the formation of more massive black holes? Are the black holes detected by LIGO as predicted by general relativity? Does gravity travel at the speed of light? The answer to all of these questions is ‘yes.’ ”
Hanna’s group found a way to conduct searches to quickly identify gravitational wave events, which have resulted in quick observations by telescopes. This was key to the groundbreaking discovery of the observation — in both gravitational waves and the entire electromagnetic spectrum — of a merging binary neutron star system in 2017.
LIGO continues to make major physics discoveries including nearly 50 black hole mergers and the merger of two neutron stars. Nominators said Hanna made crucial contributions to these key discoveries.
The signal analysis methods he helped develop that use cutting-edge algorithms led to the rapid identification of the observed signals from merging black holes. He also helped employ automatic alerts that quickly alerted astronomers worldwide that interesting celestial events were occurring. This alert system has been used by LIGO for the past three years.
“Dr. Hanna has proven himself to be a leading scientist who has made forefront contributions to one of the major physics discoveries of modern times,” a nominator said. “He is also a conscientious educator who is committed to improving undergraduate education at Penn State, and he is an excellent research mentor. Finally, he has made energetic and thoughtful service contributions at Penn State and beyond.”