USTC Astronomy Seminar Series: 2024 Fall
Early-type Dwarf Galaxies in the Local Universe: Morphology and Environment
Sanjaya Paudel 教授
Yonsei University
2024/09/05, 4:00pm , the 19th-floor Observatory Hall
报告人:
Prof. Sanjaya Paudel holds a Ph.D. in astrophysics from Heidelberg University, Germany (2011). After completing PhD, he was a Postdoctoral fellow at the Center for Alternative Energy (CEA), Paris, France, and the Korea Astronomy and Space science Institute (KASI), Daejeon, Korea. He joined Yonsei University in 2019 as a research professor at the Department of Astronomy. His research interests include the formation and evolution of dwarf galaxies in various environments and searching for their tidal features using large-scale imaging surveys like the SDSS and Legacy Survey. He has published the two largest catalogs of dwarf galaxies, merging the dwarf galaxies catalog and the early-type dwarf galaxy catalog.摘要:
We have prepared an extensive catalog of 5405 early-type dwarf (dE) galaxies located in the various environments, i.e., clusters, groups, and fields, of the local universe (z < 0.01). With a thorough analysis of the dE population with respect to their immediate environment, we find that the association between dEs and their nearest bright neighbor galaxies suggests that dEs are more likely created where their neighbors are non-star-forming ones. Using a standard definition commonly used in literature, we identify 100 ultra-diffuse galaxies (UDGs), which comprise 2% of the dE population and are more likely to be found in a group environment than a cluster environment. In this talk, I will share my experiences searching and classifying dwarf galaxies within large-scale datasets. I will discuss the limitations and challenges encountered during this process while also exploring the potential future advancements that can be achieved by using AI algorithms by machines.