Title: Probing Star Forming Regions with Sulfur-bearing Species

Speaker: Ziwei Zhang (RIKEN)

Abstract: Sulfur is abundant in the universe and on Earth, produced in stellar cores and crucial for life. While sulfur is highly depleted in dense molecular clouds, sulfur-bearing species are effective probes of the physical conditions of various energetic environments. In this seminar, I will discuss our recent studies on sulfur-bearing species in star-forming regions. With low-mass protostars, we reveal their structures and physical conditions using volatile species (e.g., SO). Moreover, we probe the ‘hot disks’ of massive protostars, where the dust is sublimated and a high fraction of sulfur is released back to the gas-phase, with refractory species (e.g., SiS). Such studies would not only assist in probing the physical and chemical properties of young stellar objects, but also better our understanding of the high depletion rate of sulfur- the ‘missing sulfur’ problem. Furthermore, solid evaporation in the “hot disks” drops a hint of the formation of primitive meteorites and thus the origin of our solar system.

Bio: Ziwei Zhang obtained her Ph.D. from University of Georgia in 2019. Since then she is a postdoc researcher at RIKEN, Japan. She has been working on various aspects of energetic astrophysical environments, with the two primary topics being star formation and molecular astrophysics. She is particularly interested in the heated environments in both low- and high-mass star-forming regions, especially in the properties of sulfur-bearing species. Her previous research on simulation and analysis of highly (ro-vibrationally) excited molecules in non-local thermal equilibrium (NLTE) environments has benefited these studies.

Time: 10:30-11:00, 24/Oct, Thursday

Venue: Room 502 (Small seminar room), Department of Astronomy 

Online connection:

https://meeting.tencent.com/dm/Bgh4WFmZhi9w

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