Apr. 10 Mon 15:00-16:30 Solar and Space Plasma Seminar Zoom / Insei Seminar Room (hybrid)
Apr. 11 Tue 10:00-11:30 太陽系小天体セミナー Zoom
Apr. 12 Wed 15:30-17:00 NAOJ Science Colloquium Zoom / the large seminar room (hybrid)
Apr. 14 Fri 16:00-17:00 NAOJ Seminar Zoom / Large Seminar Room (hybrid)
詳細は下記からご覧ください。
=============== Apr. 10 Mon ===============
Campus： Mitaka
Seminar： Solar and Space Plasma Seminar
Regularly Scheduled/Sporadic： Scheduled
Date and time：10th Apr (Mon), 15:00-16:30
Place： hybrid (Insei Seminar Room or Zoom)
Speaker：Pablo Santamarina
Affiliation：Instituto de Astrofísica de AndalucíaTitle：Fabry-Perot interferometers in Solar Physics. A novel approach to correct the data.
Abstract：
Fabry-Perot interferometers (FPIs) are fairly common in the field of solar observations as they make for excellent wavelength-tunable and narrow-band filters. They are present in several instruments, such as PHI aboard the Solar Orbiter mission, or IMaX and Tumag in the Sunrise missions, among many others. Although FPIs have numerous advantages, they also present a series of disadvantages when correcting and interpreting the data.
In this talk I propose a novel approach to use and correct the data of these instruments, and thus, increase the confidence of the scientific results achieved by them.
Facilitator
-Name：Takayoshi oba
-Comment：in English
=============== Apr. 11 Tue ===============
キャンパス：三鷹
セミナー名：太陽系小天体セミナー
定例・臨時の別：定例
日時：4月11日（火曜日）10時00分～11時30分
場所：zoom
講演者：和田空大
世話人：渡部潤一
=============== Apr. 12 Wed ===============
Campus：Mitaka
Seminar：NAOJ Science Colloquium
Regularly Scheduled/Sporadic：Every Wednesday
Date and time：2023 April 12, 15:30-17:00
Place：zoom / the large seminar room (hybrid)
Speaker：Suchetha Cooray
Affiliation：NAOJ
Title：Learning Representations of Galaxies from Observations and Simulations
Abstract：In recent years, advances in machine learning have allowed astronomers to extract valuable insights from large datasets of observations and simulations. Traditionally, representing information of these datasets has been through summary statistics like the scaling relations, stellar mass functions, and correlation functions. However, we now know that there is plenty of information that may be missed out through the use of summary statistics. Therefore, there is a strong motivation to learn efficient representations made possible through unsupervised machine learning. In this talk, I will present two applications of representation learning on observations and simulations. The first application shows that the emissions of local galaxies can be represented by two parameters that correspond to the galaxy’s evolutionary stage and scale. The second application presents a data-driven model of star formation history (SFH) constructed by finding an efficient representation of simulated SFHs in cosmological simulations. This data-driven SFH model contains the physics included in the simulations and can be used to constrain observed SFHs. I will cover the machine learning techniques used to learn the efficient representations for anyone interested in such methods.
Facilitator
-Name：Akimasa Kataoka
=============== Apr. 14 Fri ===============
Campus：Mitaka
Seminar：NAOJ Seminar
Regularly Scheduled/Sporadic：Regularly Scheduled
Date and time：2023 Aprl 14, 16:00-17:00
Place： Zoom/Large Seminar Room(hybrid)
Speaker:Zongnan Li
Affiliation：National Astronomical Observatories, Chinese Academy of Sciences
Title：Understanding Galactic Circumnuclear Environments in M31 and M81 with Multi-wavelength, High-definition Observations
Abstract：Galactic Circumnuclear regions, where billions of stars and putative supermassive black holes (SMBHs) interact intensely with the surrounding interstellar medium (ISM), play a crucial role in our understanding of the feeding and feedback of SMBHs, as well as the co-evolution of the central black hole and the host galaxy. However, the direct connection between black hole feedback and the properties of the surrounding ISM remains elusive. This work makes use of multiwavelength observations to study the multiphase ISM in the circumnuclear regions of nearby galaxies (M31 and M81) in order to understand the details of this interaction. These closest galaxies provide us with a full-band, spatially-resolved view of galactic nuclei, serving as unique laboratories for understanding SMBH feedback. Through millimeter and infrared observations, it has been found that the cold gas is severely deficient in the circumnuclear region of M31 compared to that in the Milky Way. Nevertheless, the cold gas temperature is much higher than that of the galactic disk, which may be related to past nuclear activities. In addition, through optical integrated field spectroscopic observations, it is also found that there is a biconical ionized gas outflow structure located at about 200 pc from M81 center, which may be directly related to the low luminosity active galactic nucleus in M81.
Facilitator
-Name：Moriya, Takashi