Apr. 17 Mon 14:30-15:30 ALMA-J seminar Zoom / ALMA building #102 (hybrid)
Apr. 18 Tue 10:00-11:30 太陽系小天体セミナー Zoom
Apr. 19 Wed 10:30-12:00 SOKENDAI Colloquium Zoom / the large seminar room (hybrid)
Apr. 19 Wed 14:30-15:30 ALMA-J seminar Zoom / ALMA building #102 (hybrid)
Apr. 19 Wed 15:30-17:00 NAOJ Science Colloquium Zoom / the large seminar room (hybrid)
Apr. 21 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. 17 Mon ===============
Campus：Mitaka
Seminar：ALMA-J seminar
Regularly Scheduled/Sporadic： Every Wednesday
Date and time： April 17th, 2023 (Mon), 14:30 – 15:30
Place： ALMA building #102 / Zoom (hybrid)
Speaker: Ryan Loomis
Affiliation: National Radio Astronomy Observatory (NRAO)
Title: The PAH Revolution: Cold, Dark Carbon at the Earliest Stages of Star Formation
Abstract: Polycyclic Aromatic Hydrocarbons (PAHs) have been implicated as a large reservoir of reactive carbon in the interstellar medium since the 1980s. They have also long been widely attributed as the carriers of the unidentified infrared bands, but it is only in the last year that individual PAHs been detected in the ISM through their rotational spectroscopic lines. In this talk, I will discuss these detections made by the GOTHAM collaboration toward the Taurus Molecular Cloud (TMC-1) using the Green Bank Telescope. In particular, I will describe our advances in observational techniques and analysis methods necessary to make these detections, our efforts to investigate the detailed chemical pathways for the formation and destruction of PAHs, and the challenges that we have faced in analyzing such a rich and extensive dataset.
Facilitator: Toshiki Saito, Andrea Silva
=============== Apr. 18 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18日（火曜日）10時00分～11時30分
場所：zoom
講演者：浦川聖太郎
世話人の連絡先
名前：渡部潤一
=============== Apr. 19 Wed ===============
Campus：Mitaka
Seminar：SOKENDAI Colloquium
Regularly Scheduled/Sporadic：Regular
Date and time：April 19, 2023 10:30-12:00
Place：Large Seminar Room in Subaru Building and Zoom
Speaker: Ryota Ikeda
Affiliation: SOKENDAI 3rd year (D1) (Supervisor: Daisuke Iono, Masayuki Tanaka, Takuma Izumi)
Title: Playing with Gas Kinematics pt.2 – Kinematical properties of CO line in z ~1.5 cluster galaxies –
Speaker : Shotaro Tada
Affiliation: SOKENDAI 4th year (D2) (Supervisor: Takayuki Kotani, Yutaka Hayano, Yosuke Minowa)
Title: Development of precise detector calibration methods for photometry and astrometry with space telescopes
Facilitator
-Name：Matsuda, Graduate Student Affairs Unit
=============== Apr. 19 Wed===============
Campus：Mitaka
Seminar：ALMA-J seminar
Regularly Scheduled/Sporadic： Every Wednesday
Date and time： April 19th, 2023 (Wed), 14:30 – 15:30
Place： ALMA building #102 / Zoom (hybrid)
Speaker: Edwige Chapillon
Affiliation: The Institut de radioastronomie millimétrique (IRAM)
Title: Observation of protoplanetary-disks with NOEMA and ALMA
Abstract: ALMA and NOEMA are 2 big mm-interferometers covering the full sky. They are ideal tools for the study of protoplanetary disks, the birth place of planets, both in continuum (dust) and molecular lines (gas). The increased spatial resolution and sensitivity of these telescopes has revolutionized our view of the protoplanetary disks, showing in peculiar that planetary formationmost likely occurs earlier than previously thought. In this talk I will present several results obtained in the latest years with ALMA and/or NOEMA, in particular the case of GG Tau, a multiple system, the cases of edge-on disks, and molecular survey allowed by the new capabilities of the NOEMA interferometer.
Facilitator: Toshiki Saito, Andrea Silva
=============== Apr. 19 Wed===============
Campus：Mitaka
Seminar：NAOJ Science Colloquium
Regularly Scheduled/Sporadic：Every Wednesday
Date and time：2023 April 19, 15:30-17:00
Place：zoom / the large seminar room (hybrid)
Speaker：Masamitsu Mori
Affiliation：NAOJ
Title：Core-collapse of white dwarfs with super Chandrasekhar mass
Abstract：Recently, Fast Radio Bursts (FRBs) from globular clusters have been reported (Kirsten et al. 2022). A model has been proposed suggesting that young neutron stars (magnetars) may be involved in causing FRBs. However, these FRBs have been observed in globular clusters where star formation has ended. This implies the possibility that young magnetars were formed in the old stellar population.
As an explanation for this celestial phenomenon, it has been proposed that a white dwarf (WD) binary system merged and exceeded the Chandrasekhar mass limit, causing a collapse due to a decrease in degenerate pressure through electron capture reactions, leading to a gravitational collapse supernova explosion rather than a type Ia supernova explosion.
Therefore, we conducted a general relativistic neutrino radiation hydrodynamics calculation for a 1.6 solar mass WD and successfully achieved an explosion. In this simulation, we assumed hydrostatic equilibrium and used the Chandrasekhar mass before gravitational collapse as the initial conditions.
In this study, we used a one-dimensional simulation and performed calculations that implemented general relativistic gravity, a state equation based on nuclear physics, and a moment method for neutrino radiation transport. First, we confirmed stability under adiabatic conditions and then calculated the process leading to gravitational collapse through a decrease in the Chandrasekhar mass due to electron capture reactions by solving the neutrino radiation transport. Up to this point, we used Newtonian gravity to reduce numerical errors. Finally, we performed an explosion calculation with consideration of general relativistic gravity for the model that underwent gravitational collapse.
The explosion reproduced in this study was very small, with an explosion energy of $3 \times 10^{48}$ erg and an ejecta mass of $5 \times 10^{-4}~M_{\odot}$.
Facilitator
-Name：Akimasa Kataoka
-Comment：English
=============== Apr. 21 Fri===============
Campus：Mitaka
Seminar：NAOJ Seminar
Regularly Scheduled/Sporadic：Regularly Scheduled
Date and time：2023 Aprl 21, 16:00-17:00
Place： Zoom/Large Seminar Room(hybrid)
Speaker: YaëlNazé
Affiliation: University of Liège
Title:Women astronomers
Abstract：Who discovered a record number of comets and asteroids . Who found a
way to organize the stellar populations ? Who discovered an important
law to derive distances in the Universe ? Who discovered cosmic
lighthouses ? Who understood how stellar forges work ? The answer to
all these questions is : women… However, when we have to name a
‘historical’ astronomer, we most often think of men: Ptolemy, Galileo,
Copernicus or Hubble. It is true that over the centuries, women have
had little access to science in general and astronomy in particular,
but that is no reason to believe that they have made no contribution
at all ! In this talk, we will follow the careers of some women
astronomers, from Antiquity to the modern times, and see how their
situation has evolved with time.
Facilitator
-Name：Moriya, Takashi