科学研究
-
2023.12.26
The “Missing baryons” in the cosmic web—what is it? Where is it? How much?
Previous studies of galaxy formation have shown that only 10 per cent of the cosmic baryons are in stars and galaxies, while 90 per cent of them are missing. In this talk, I will present several observational studies that coherently find significant evidences of the missing baryons. The first measurement is the cross-correlation between the thermal Sunyaev-Zeldovich effect with gravitational le...
详情 -
2023.12.25
A cooling anomaly of white dwarfs
Data from the Gaia satellite are revolutionizing many fields of astronomy. I will present two related discoveries about white dwarfs: one is an extreme cooling anomaly upon phase transition of some white dwarfs, which stops their cooling for almost 10 Gyrs, and the other is the existence of merger products among single white dwarfs. I will show interesting solution to explain the anomaly and th...
详情 -
2023.12.25
Constraining the Cosmic Partition of IGM and CGM Baryons with FRB Foreground Mapping
The frequency shifts measured in extragalactic Fast radio bursts (FRB)s probe the total column of ionized gas in the foreground, including large contributions from the CGM and IGM. By combining this information with both deep and wide spectroscopic observations of foreground galaxies, the information content is enhanced. The wide-field data (∼10s of Mpc scales) allows us to reconstruct the u...
详情 -
2023.12.22
The three regimes of atmospheric evaporation for super-Earths and sub-Neptunes
A significant fraction of super-Earths and sub-Neptunes are thought to experience an extreme loss of volatiles because of atmospheric evaporation in the early stages of their life. Though the mechanisms behind the extreme mass loss are not fully understood, two contenders have been widely discussed: photoevaporation from X-ray and ultraviolet irradiation and core powered mass loss. In this talk...
详情 -
2023.12.21
Probing Planet Formation with the Most Extreme Cases
Thousands of exoplanets have been discovered in the past ~30 years. However, there are still major gaps of knowledge in our understanding of planet formation. The most extreme exoplanets are often ideal for identifying, isolating, and investigating critical aspects of plant formation. In this talk, I will highlight three extremes of planet formation: 1) the ultra-short-period planets (
详情