Dr. Fereshteh Rajabi was born in northwest Iran and did her undergraduate studies in Atomic Physics at the University of Tehran. She moved to the United States in 2009 where she obtained a MSc in Atomic Physics at Wesleyan University, Connecticut, working in a Laser Spectroscopy laboratory studying the statistics of atomic systems at the boundary between quantum and classical physics. While at Wesleyan, Fereshteh became very interested in research on astrophysical processes. At the end of 2010, she came to Canada and started a second MSc, this time in Astronomy at the University of Western Ontario, where she worked on identifying potential magnetic dipole maser lines. Her interest in applying the principles of quantum physics to the interstellar medium were met for her PhD studies, where she worked on Dicke’s superradiance, a well-known phenomenon in the quantum physics community, and investigated the possibility of superradiance in astrophysics. Both her PhD and Master’s were done under the supervision of Dr. Martin Houde at the University of Western Ontario.
Fereshteh is currently a Postdoctoral Fellow in the Institute for Quantum Computing (IQC) at the University of Waterloo. At the IQC, her research is focused on the study of light-matter interactions in quantum systems. Her goal is to learn and better understand quantum phenomena studied in physics laboratories and apply them to astrophysics.
Title: Dicke’s Superradiance in Astrophysics
It is generally assumed that, in the interstellar medium, much of the emission emanating from atomic and molecular transitions within a radiating gas happen independently for each atom or molecule, but as was pointed out by R. H. Dicke in a seminal paper several decades ago, this assumption does not apply in all conditions. As will be discussed in this talk, and following Dicke’s original analysis, closely packed atoms/molecules can interact with their common electromagnetic field and radiate coherently through an effect he named superradiance. Superradiance is a cooperative quantum mechanical phenomenon characterized by high intensity, spatially compact, burst-like features taking place over a wide range of time-scales, depending on the size and physical conditions present in the regions harbouring such sources of radiation. I will discuss the application of superradiance to the CH3OH 6.7-GHz and H2O 22-GHz maser lines, and show that superradiance provides a valid explanation for previous observations of intensity flares detected in these spectral lines for some astronomical sources. An interesting result is that superradiance provides a natural mechanism for the recent observations of periodic and seemingly “alternating” methanol and water flares in G107.298+5.639 that cannot be explained within the context of maser theory.