Fwd: NCTS Astrophysics Student Lunch Seminars [July to December 2025]
Dear colleagues,
We will have our monthly NCTS Astrophysics Student Lunch Seminars next Friday, 10/31, from 12pm in the 4F lecture room in the Cosmology Hall. Talk details are appended below. You can sign up for lunch boxes here:
https://forms.gle/MafsWr3PMpsYSZDs5
Please come and support our students.
Cheers, Min-Kai
1. “Brick” or “Mist”? Investigating Gas Dynamics in Cool-core Galaxy ClustersYi-Yang Lee (NTHU, supervisor: Hsiang-Yi Karen Yang) Intracluster medium (ICM, or hot gas) with strong X-ray emissions and cold gas (T~10^4K) nebular gas with optical emissions interact with each other at the central regions of some cool-core galaxy clusters; this interaction plays a crucial role in the cluster evolution. We aim at comparing the gas kinematic between the observations of cool-core clusters and our simulations in order to interpret the dynamical properties of cold and hot gas in clusters. Hydrodynamic simulations with two different scenarios of cold gas properties, modeled as “Brick” or “Mist”, are performed to trace their kinematics. By calculating the cold gas time-averaged line-of-sight velocity, velocity dispersion and comparing observed values, we found the observations do not have a clear preference on Brick-like or Mist-like cold gas. On the other hand, recent XRISM observations of the hot gas prefer the predicted values from the Brick simulation, indicating the cold gas is likely to be dense, clumpy gas rather than misty, tiny cloudlets that passively floating within the cluster.
2. Transit Timing Constraints on the Maximum Exomoon Mass Prangsutip Cherdwongsung (NTHU, supervisor: Ing-Guey Jiang)
The search for exomoons, moons orbiting exoplanets, is one of the most exciting challenges. This study investigates the use of transit timing variations (TTV) and transit duration variations (TDV) as indirect methods to detect potential exomoons. By analyzing periodic shifts in transit mid-times and durations from the synthetic light curves that include TESS-like noise, we aim to identify the dynamical signatures that indicate the gravitational influence of an orbiting moon. Our current focus is the WASP-31b system, which exhibits unusually strong sodium (Na I) and potassium (K I) absorption features that may originate from volcanic activity on unseen exomoons, as proposed by Oza et al. (2019). We estimate the maximum exomoon mass that can remain dynamically stable within this system. These results help assess the plausibility of exomoons around hot Jupiters and guide future observations to confirm their presence.
———- Forwarded message ——— From: Min-Kai Lin mklin@asiaa.sinica.edu.tw Date: Mon, Jul 14, 2025 at 11:41 AM Subject: NCTS Astrophysics Student Lunch Seminars [July to December 2025] To: riaa riaa@asiaa.sinica.edu.tw, ncts-tca-all@googlegroups.com, < tan@asroc.org.tw>
Dear colleagues,
The NCTS Astrophysics group is resuming our monthly student seminar series. These provide opportunities for our domestic students to share their work and practice giving live talks. The schedule for the rest of the year is appended below. Seminars begin at 12pm in the 4F lecture room in the Cosmology Hall on the NTU campus. Talks are open to all.
Sign up links for lunch boxes will become available from the NCTS seminar list a week before the talks:
https://phys.ncts.ntu.edu.tw/en/act/Seminars/seminars_TG2
Cheers, Min-Kai
Date Speaker 1 Affiliation Supervisor Speaker 2 Affiliation Supervisor 2025/7/24 Pon-Yin Wang TKU Hsi-An Pan 2025/8/22 Tsung-Han Chuang NTNU Yueh-Ning Lee 2025/9/26 Chiung-Yin Chang NTHU Hsiang-Yi Karen Yang Huan-Ping Chao NCKU Kwan-Lok Li 2025/10/31 Yi-Yang Lee NTHU Hsiang-Yi Karen Yang Prangsutip Cherdwongsung NTHU Ing-Guey Jiang 2025/11/28 Yu-Xuan Nancy Lin NYCU Shih-Ping Lai Tz-En Gau NTU Chia-Yu Hu 2025/12/26 Szu-Ting Chen NTHU Shin-Ping Lai Afif Ismail NTNU Hung-Yi Pu