The Heineman Foundation, at the American Institute of Physics, and American Astronomical Society, announced Professor Norman Murray as the winner of the 2022 Dannie Heineman award for Astrophysics.
Dannie Heineman award for astrophysical achievements
The Heineman committee have selected Norman Murray as the winner of the Dannie Heineman award “for his deep theoretical insight into an exceptionally broad range of astrophysical phenomena, including the dynamics of planetary systems, accretion disk winds in active galactic nuclei, and star formation and feedback in galaxies.”
“As I looked over the list of past recipients of the Heineman Prize, I felt both thrilled and humbled. I’ve been fortunate to work in such an exciting period of discovery in astronomy,” explained Murray. “I have been lucky to work with so many great people. They have taught and inspired me. I hope, in turn, to teach and inspire others.”
“AIP congratulates Dr Murray for this achievement and his work into many of the phenomena that occur in our universe,” commented Michael Moloney, chief executive officer of AIP. “One can only be impressed by the significant breadth of the scope of his work – from understanding the formation of planets to the nature of some of the most active galactic-scale phenomena in the universe. And with his work being informed by observations across the electromagnetic spectrum, his research is universal in many dimensions.”
Life cycle of quasars
In addition to studying protoplanets, Murray has also investigated the life cycle of quasars, the brightest objects in the universe, and how they influence their host galaxies.
“I am delighted to see this prestigious Dannie Heineman award go to Professor Murray,” said AAS president Paula Szkody. “His broad knowledge of physical principles, which he has applied to helioseismology and the solar magnetic field, planetary systems within and outside our solar system, star and galaxy formation, and active galactic nuclei and winds, has contributed to major advancements in both physics and astronomy.”
Murray credits his third-grade teacher, Mrs. Adamack, for inspiring his nascent interest in the physical world. She purchased a 3-inch refracting telescope for him that came with a solar filter so he could observe sunspots safely. Growing up in a rural area with very little light pollution, it enabled him to see the Milky Way without a telescope. By using the gift from his teacher, he could see details in brighter planets such as Venus, Jupiter.
Years later, Murray circled back to the night sky in his quest to understand the most luminous and energetic objects in the universe, quasars. These supermassive black holes slowly accrete gas from a disk, and Murray wanted to know how they worked.
“In the 1990s, my co-workers and I figured out how the intense light of a quasar drives winds,” Murray explained. “These winds produce characteristic emission and absorption lines, providing astronomers a means by which to measure the redshift, and hence, the distance to the quasar. Many years later, I realised, along with several others, that these winds could affect the rate at which galaxies produced stars. I should note that the exact mechanism is still being worked out.”
Protoplanets
A clearer understanding of how galaxies produce stars led him to look at how stars produce protoplanets – large bodies of mass surrounding a star, with the potential to become a planet. Just as intense energy of quasars is the product of gravity, the fundamental force, similarly, plays a significant role in how stars are formed.
“Gravity from the gas in galactic disks, acts on the gas itself, playing a major role in star formation as well as galaxy evolution,” Murray said. “The self-gravity drives accretion toward the centre of the galaxy, while at the same time producing clumps, known as giant molecular clouds. This is where stars form.
“Protoplanetary disks are in between quasar disks and galactic disks when it comes to self-gravity. The presence of self-gravity, early in the birth of the star, is important. However, as the system ages, despite ever increasing accumulation of mass, self-gravity becomes less of a player. Comparing these cases is very instructive.”
When asked for advice, Murray said, “Stay curious, learn as much physics as you can, talk to as many people as you can. Oh yes, exercise daily. That advice comes from Peter Goldreich, my dorm resident associate at Caltech, when I was an undergraduate.”
Currently, after winning the Dannie Heineman award, Murray’s research is focused on black holes and protoplanetary disks but has also taken a closer look at our home planet, studying the effects of thermal tides on the Earth’s length of day and month. Thermal tides, as opposed to lunar tides, are the result of the sun heating the Earth’s atmosphere.
