Home-Tianyi Yang Astro

About me

⭕️ I am a PhD student studying at the Institute for Astronomy, the University of Edinburgh, supervised by Dr. Yanchuan Cai and Dr. John Peacock.

⭕️ My research interest is in observational cosmology and galaxy formation: I study the matter distribution in galaxies and large-scale structures using galactic kinematics, gravitational lensing and simulations. I also study the gas properties through thermal SZ effect from simulations and observational data.

⭕️ I finished my Bachelor (2018) and Master (2020) degree at the University of Waterloo, under the supervision of Dr. Mike Hudson and Dr. Niayesh Afshordi. My Master thesis can be found here.

⭕️ My publications can be found on arXiv and ADS , or on Google Scholar.

left: credit to https://www.nature.com/collections/dttrsdkjww/, right: credit to https://www.universetoday.com/135954/largest-scales-milky-way-galaxy-middle-nowhere/

Research

Here are some brief descriptions of my research fields

Dark matter and light distribution in the filaments

Current cosmological model predicts that dark matter haloes are connected by filaments. However, direct measurements of the masses and structure of these filaments are difficult. In one of our works, we study the total matter distribution of filaments between stacked galaxy pairs using gravitational lensing, as well as the light distribution between stacked pairs (see the maps below). In another work of ours, using dark-matter-only N-body simulations, we study their dark matter distributions in more details by fitting the measured stacked filament density profile to a universal functional form (see the curve below).

Galaxy formation

Unlike dark matter, gas distribution in or around haloes can be affected by various galactic activities, such as active galactic nucleus (AGN in short) feedback. One useful tool used for probing the gas physics around haloes is thermal SZ effect. By studying the correlation between SZ amplitude and other halo properties, one can gain some insight into how gas distributions are altered by different feedback mechanisms in galaxies. In the figure below, we show an example of SZ amplitude-halo mass relation to study the effect of galactic activities on gas distributions in/around massive haloes. More details can be found here.

Previously, I also worked on studying the dark matter properties of our own Milky Way using stellar kinematics. Please refer to this link for more details.