Hi, I’m
Yuan Qi
GET IN TOUCH:
Chris (Yuan Qi) Ni
University of Toronto
chris.ni@mail.utoronto.ca
I’m a PhD candidate in the Department of Astronomy and Astrophysics at the University of Toronto. I think new pieces of the puzzle can always be found in unique and novel data. Recently, I’ve been searching for signs of radioactive elements in the infant stages of supernova explosions, and shedding new light on how they explode. I am currently working with Professors Dae-Sik Moon and Maria R. Drout.
Projects 1/2
The Type Ia Supernova Origin Problem
Attempts to understand the nature of Supernovae span the entire history of science, starting as early as 185 AD. Most of the elements heavier than H and He are produced in Supernova explosions, including the building blocks of life itself. In particular, Type Ia Supernovae are used to measure distances across the Universe, famously leading to the discovery of accelerated cosmological expansion and Dark Energy. Most of my recent research has focused on using data obtained by novel facilities to advance our understanding of how Type Ia Supernovae explode.
Videos shown are of the two earliest Type Ia Supernovae ever discovered, imaged by the Korea Microlensing Telescope Network in their hours of infancy. This new data reveals brief flashes of light reddened by absorption lines of iron-group elements near the surface of the explosion, bringing us closer to understanding its origin.
Supernova 2018aoz published in
Supernova 2021aefx published in
Publications by
Yuan Qi et al.
READ 》Ni, Y. Q. et al. (2024), Infant type Ia supernovae from the KMTNet I. multi-color evolution and populations, submitted to Astrophysical Journal (August 12)
READ 》Ni, Y. Q. et al. (2023), Origin of high-velocity ejecta and early red excess emission in the infant Type Ia SN 2021aefx, Astrophysical Journal, 959. 132.
READ 》Ni, Y. Q. et al. (2022), Infant-phase reddening by surface Fe-peak elements in a normal type Ia supernova, Nature Astronomy, 6, 568 (cover article of the May 2022 issue; Volume 6 Issue 5)
READ 》Ni, Y. Q. et al. (2023), The origin and evolution of the normal type Ia supernova 2018aoz with infant-phase reddening and excess emission, Astrophysical Journal, 946, 7.
READ 》Moon, D.-S., Ni, Y. Q. et al. (2021), Rapidly declining hostless type Ia supernova KSP-OT-201509b from the KMTNet Supernova Program: transitional nature and constraint on 56Ni distribution and progenitor type, Astrophysical Journal, 910, 151.
READ 》Afsariardchi, N., Moon, D.-S., Drout, M. R., González-Gaitán, S., Ni, Y. Q., et al. (2019), KSP-SN-2016kf: a long-rising H-rich type II supernova with unusually high 56Ni mass discovered in the KMTNet Supernova Program, The Astrophysical Journal, 881, 22.
READ 》Brown, S., Moon, D.-S., Ni, Y. Q. et al. (2018), High-cadence multi-color observations of the dwarf nova KSP-OT-201503a by the KMTNet Supernova Program, Astrophysical Journal, 860, 21.
READ 》Antoniadis, J., Moon, D.-S., Ni, Y. Q. et al. (2017), Discovery of a rapid, luminous nova in NGC 300 by the KMTNet Supernova Program, Astrophysical Journal, 844, 160.
Projects 2/2
Origin of structure in nebulae
I am also investigating the origin of structures seen in Supernova Remnant as well as Planetary Nebulae. In particular, axial and shell structures observed in some Planetary Nebulae (video shown) are thought to originate from poorly understood evolutionary processes of their central white dwarf binaries which are on track to explode as Type Ia Supernovae.
[3] Video is from my integral-field spectroscopy of NGC 6826, acquired with the Wide Integral-Field Infrared Spectrograph designed at the University of Toronto. The observations were performed at the 1.5-metre Bok Telescope in KPNO.
