Li: Radio Galaxies and the CMB: Opportunities for Millimeter-Wave Surveys / Ma: Decipher the ubiquitous bursty phase in high-redshift galaxy formation

Dec 01, 2020 - 11:00 am to 12:00 pm
Zack Li (Princeton) / Xiangcheng Ma (UC Berkeley) via zoom

Zoom info:

Zack Li:

We're producing some exciting data with high-resolution, ground-based observations of 30 - 300 GHz, using experiments like ACT, SPT, and (soon) SO. We expect these observations to yield new science across a broad range of scales --dust, galaxies, and the Universe.

In this talk, I'll focus on one promising avenue for discovery: these surveys will double as deep, multi-frequency surveys of radio galaxies. Such galaxies contaminate cosmological analysis, but they also offer a view of AGN activity across cosmic time. I'll discuss our new simulated maps of radio galaxies, which use the Websky simulations to include realistic spatial correlations of radio sources with the cosmic infrared background, lensing, and clusters. I'll also talk about the many unknown properties of these objects that we hope to learn from upcoming surveys.

Xiangcheng Ma:

Galaxy formation is an essential research area in astronomy. High-resolution cosmological zoom-in simulations with realistic multi-phase ISM, star formation, and feedback models have significantly advanced our understanding of galaxy formation theory in recent years. One most important prediction is dwarf and high-redshift galaxies exhibit “bursty” star formation with the ISM characterized as highly chaotic and turbulent. The bursty regime is poorly understood, as different simulation groups produce diverging galaxy properties. I will briefly show how bursty SF affects our understanding of galactic chemical evolution, cosmic reionization, globular cluster formation, and supermassive black hole growth. I will discuss what predictions can be tested by future observations with JWST and 30 m-class telescopes and how these observations can be used to constrain star formation and feedback models in galaxy formation simulations.