なお、当談話会は天文学研究者・学生を対象に大学・大学院での 専門的な研究と教育を目的として開催されています。 一般の方は公開講座・講演会などにご参加いただければ幸いです。
ML: semiadm _at_ ioa.s.u-tokyo.ac.jp
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Abstract: This talk will present first results of the MIRI-MRS spectra of a number of protostars, T Tauri and brown dwarf disks resulting from the JOYS and MINDS GTO programs as well as a number of open time programs. Rich ice spectra are seen in dark clouds and the cold outer envelopes of protostars hinting at the presence of complex molecules in ices formed very early in the evolution. In young and mature disks, many lines from gaseous CO, H2O, CO2, C2H2 and HCN are found, but also surprising new molecules are detected. Together they point to a rich chemistry that is linked to the physical structure of the inner regions of these disks and thereby provides a unique diagnostic of it. Background information: the 55 hr JWST Observations of Young protoStars (JOYS) GTO program (PI: van Dishoeck) uses MIRI to investigate the physical and chemical properties of two dozen protostars and their immediate environment. JOYS studies the physical characteristics of embedded disks, accretion signatures onto the protostars, feedback from the young protostars on their environment through primordial jets and outflows, as well as the chemical gas and ice constituents of the protostellar envelopes to feed the disks. The goal of the 120 hr MIRI Mid INfrared Disk Survey (MINDS) GTO program (Th. Henning, I. Kamp co-PIs) is to use JWST to (1) investigate the chemical inventory of the terrestrial planet forming zone, (2) to follow the gas evolution into the disk dispersal stage, and to (3) study the structure of protoplanetary and debris disks in the thermal mid-IR. The program builds a bridge between the chemical inventory of planet-forming disks and the properties of exoplanets. In total, about 50 targets (Herbig Ae stars, T Tauri stars, brown dwarfs and young debris disks) are being observed.
Abstract: Gravitational microlensing has a unique strength in its sensitivity to planets with masses as low as Earth mass just beyond the snow line, where the core accretion theory of planetary formation predicts the most efficient planet formation. Because it does not rely on the light from the host star, microlensing can detect the planets orbiting around faint stars such as M-dwarfs and brown dwarfs, as well as free-floating planets, and black holes. So far, about 250 exoplanets were found by this method thanks to survey observations by MOA (Microlensing Observations in Astrophysics), OGLE (Optical Gravitational Lensing Experiment) and KMT-Net (Korean Microlensing Telescope Network) groups. In this talk, I will present recent results provided by microlensing observations. I will also talk about the PRIME (PRime-focus Infrared Microlensing Experiments) project, which has recently started survey observations towards the Galactic center in infrared in South Africa.
|405||2023年10月3日(火) 天文学教室との合同談話会||Ewine van Dishoeck (Leiden Observatory)||Protostars and protoplanetary disks with JWST: first results from the JOYS and MINDS programs||N. Matsunaga|
|406||2023年10月26日(木)||平尾優樹 (天文学教育研究センター)||The latest findings and future prospects in exoplanet studies through gravitational microlensing||TBA|
|403||2023年6月8日(木)||今井正尭 (天文学教育研究センター)||Observations of planetary-scale waves on Venus atmosphere||S. Koyama|
|404||2023年6月29日(木)||谷口琴美 (国立天文台・科学研究部)||Chemical complexity around massive young stellar objects revealed by ALMA||K. Kohno|
|402||2023年5月25日(木)||藤田真司 Shinji Fujita (Institute of Astronomy, the University of Tokyo)||Distance determination of molecular clouds in the Galaxy using deep learning||M. Imai|
|401||2023年4月20日(木)||Yao-Lun Yang (Research Scientist, RIKEN)||Complex chemistry in the era of JWST and ALMA||K. Kohno|
|400||2023年4月6日(木)||Doug Johnstone (National Research Council Canada)||What the Variability of Embedded Protostars Tells Us about Accretion: Past, Present, and Future||K. Kohno|