カテゴリー: 科学研究部コロキウム

January 23 Tue 10:00-11:30 太陽系小天体セミナー
Zoom

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January 24 Wed 10:30-12:00 SOKENDAI Colloquium
Large Seminar Room in Subaru Building and Zoom (hybrid)

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January 24 Wed 13:00-15:00 SOKENDAI Doctoral Thesis Dissertation review
Lecture Room and Zoom (hybrid)

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January 24 Wed 13:30-15:00 Solar and Space Plasma Seminar
Insei Seminar Room and Zoom(hybrid)

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January 24 Wed 14:30-15:30 ALMA-J seminar
Room 102 in the ALMA Building and Zoom (hybrid)

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January 24 Wed 15:30-16:30 NAOJ Science Colloquium
the 3F seminar room in Instrument Development Building No.3 and Zoom (hybrid)

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詳細は下記からご覧ください。

=============== January 23 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：1月23日（火曜日）10時00分～11時30分
場所：zoom
講演者：匠あさみ

世話人の連絡先
　名前：渡部潤一

備考：テレビ会議またはスカイプによる参加も可

=============== January 24 Wed ===============

Campus：Mitaka
Seminar：SOKENDAI Colloquium
Regularly Scheduled/Sporadic：Regular
Date and time：January 24, 2024 10:30-12:00
Place：Large Seminar Room in Subaru Building and Zoom

Speaker: Takumi Kakimoto
Affiliation: SOKENDAI 2nd year (M2) (Supervisor: Masayuki Tanaka, Daisuke Iono, Kiyoto Yabe)
Title: Star formation activity in a massive protocluster at z=4.5

Speaker: Chanoul Seo
Affiliation: SOKENDAI 5th year (D3) (Supervisor: Yuka Fujii, Masahiro Ikoma, Hideko Nomura)
Title: Impact of Magma Redox States on Super-Earth Atmospheres:Unveiling the Connection with Atmospheric Composition

Facilitator
-Name：Matsuda, Graduate Student Affairs Unit

=============== January 24 Wed===============

Campus：Mitaka
Seminar：SOKENDAI Doctoral Thesis Dissertation review
　　　　総研大博士学位論文予備審査会
Regularly Scheduled/Sporadic：Sporadic
Date and time：January 24, 2024 13:00-15:00
Place ：Lecture Room and Zoom

Speaker：Takaho Masai
Title：A Study on the Design of Receiver Optics and Waveguide Components Towards High-Performance (Sub)millimeter Wave Multibeam Receivers

Facilitator
-Name：Nozomu Tominaga, Hideyuki Kobayashi, Kaya Kitabayashi (Graduate Student Affairs Unit)

Comment:
https://guas-astronomy.jp/CampusLife/doctor_report.html

=============== January 24 Wed==============

Campus： Mitaka
Seminar： Solar and Space Plasma Seminar
Regularly Scheduled/Sporadic： Sporadic
Date and time：24 January (Wed), 13:30-15:00
Place： hybrid; Insei Seminar Room and Zoom

Speaker：Dr. Yoichiro Hanaoka
Affiliation：NAOJ
Title：Observation of the White-Light Corona at Total Solar Eclipses (Focusing
on Polarization Measurements)
Abstract：Total solar eclipses are good chances to observe the inner white-light corona under a very low background level. Combining the eclipse data and those from spaceborne coronagraphs such as SOHO/LASCO, we can obtain the distribution of the coronal material regardless of the temperature from just above the limb to tens of solar radii.
For this purpose, we carried out eclipse observations several times with amateur observers using polarimetry instruments. Polarimetry is indispensable to separate the K-corona (million-kelvin plasma) from the F-corona (interplanetary dust), and therefore, all the spaceborne coronagraphs have polarimetric capacity.
The results from the eclipses unexpectedly show a systematic difference between the polarimetry results obtained during the eclipses and those by LASCO. The degree of polarization obtained by LASCO is about 30 % less than the eclipse results and it was revealed that combining the eclipse and LASCO data is difficult. This result suggests that the polarimetric calibration of LASCO should be re-examined.
Some future space missions carrying white-light coronagraphs are planned, and they may also have difficulty in polarimetric calibrations. Repeated eclipse observations are expected to provide good calibration data for space coronagraphs. After a consistent calibration becomes possible, the precise distribution of coronal material in the wide range will be obtained.

Facilitator
-Name：Akiko Tei

Comment：English

=============== January 24 Wed==============

Campus: Mitaka
Seminar: ALMA-J seminar
Date and time: January 24 (Wed) 14:30-15:30
Place: hybrid (Room 102 in the ALMA building and Zoom)

Speaker: Kianhong Lee
Affiliation: Tohoku University
Title: ALMA [CII] observations of TN J0924-2201, the radio galaxy at z~5.2

Abstract:
High-redshift radio galaxies are massive star-forming galaxies with powerful radio jets, often located on or below the star-forming main sequence of galaxies, indicating that they are in the process of being quenched. TN J0924-2201 is one of the most distant known radio galaxies, associated with three CO(1-0)-detected companions at z~5.2. In this talk we will present ALMA observations of [CII] 158 um line and the corresponding 1-mm continuum emission of TN J0924-2201. While obtaining the [CII] line and 1mm continuum emission at the host galaxy, our observations revealed no detection at the positions of the three CO(1-0) companions. The derived systematic redshift z_[CII] of the host galaxy from the [CII] is ~5.17, indicating a velocity offset of ~1200 km/s with respect to z_Lya, marking the largest velocity offset between [CII] and Lya recorded at z > 5 to date. Within the host galaxy, we identified an extended [CII] structure with a velocity of ~700 km/s, suggestive of an outflow. This finding aligns with the shell outflow model, providing consistency with the observed large velocity offset of Lya. Assuming three massive CO(1-0) companions are also outflows, their velocities of ~1500 km/s surpass the escape velocity of a 10^13 Msun halo, implying the removal of molecular gas from the system of TN J0924-2201. Our observations and results revealed that we are witnessing a distinctive phase of radio galaxies in their evolution.

=============== January 24 Wed==============

Campus: Mitaka
Seminar: NAOJ Science Colloquium
Date and time: 2023 Jan. 24 (Wed.), 15:30-16:30
Place: the 3F seminar room in Instrument Development Building No.3 / Zoom (hybrid)

Speaker: Ryota Ichimura
Affiliation: NAOJ (D1)
Title: Carbon Isotope Fractionation of Complex Organic Molecules in Star-Forming Cores
Abstract:
Recent high-resolution and sensitivity ALMA observations have unveiled the carbon isotope ratios (12C/13C) of Complex Organic Molecules (COMs) in a low-mass protostellar source. To understand the 12C/13C ratios of COMs, we investigated the carbon isotopic fractionation of COMs from prestellar cores to protostellar cores with a gas-grain chemical network model. We confirmed that in the prestellar phase, the 12C/13C ratios of small molecules are bimodal: CO and species formed from CO (e.g.,CH3OH) are slightly enriched in 13C compared to the local ISM (by ∼ 10 %), while those from C and C+ are depleted in 13C owing to isotope exchange reactions. COMs are formed from the simple species on grain surface, and thus basically inherit the bimodality of 12C/13C. In the protostellar phase, COMs are formed on the grain surface and in the hot gas (> 100 K) and have different 12C/13C from those in the prestellar phase. We additionally incorporate reactions between gaseous atomic C and H2O ice or CO ice on the grain surface to form H2CO ice or C2O ice suggested by recent laboratory studies. The direct C-atom addition reactions open pathways to form 13C-enriched COMs from atomic C and CO ice. We find that these direct C-atom addition reactions mitigate isotope fractionation, and the model with the direct C-atom addition reactions better reproduces the observations than our base model. Our calculations also show that cosmic-ray ionization rates affect the 12C/13C ratios of COMs.

Speaker: Akifumi Matsumura
Affiliation: The University of Tokyo (M1)
Title: Estimating the characteristics of ejecta from magma ocean for water production on the protoplanet
Abstract:
How water is delivered to rocky planets during the planet-forming stage is a major issue in planetary science. While many previous studies considered water delivery by icy planetesimals, we consider water production by chemical interaction between the primordial atmosphere and the surface of the magma ocean of a rocky planet growing through planetesimal accretion. Previous studies based on this idea assumed that iron oxides in the magma ocean and atmospheric hydrogen are always in constant contact, which must be examined; namely, we need to consider properly how to bring the magma into contact with the atmosphere. In this study, we focus on the reaction between the atmospheric gas and the materials ejected from the magma ocean when planetesimals collide with the magma ocean surface during the growth phase of a planet. I am currently studying the scatter of magma upon the impact of planetesimals on the planet’s surface and its influence on the atmospheric composition. In this talk, I will describe our progress in the research to date and future research plans.

Facilitator
-Name: Kanji Mori

Comment: English

January 16 Tue 10:00-11:30 太陽系小天体セミナー
Zoom

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January 17 Wed 10:30-12:00 SOKENDAI Colloquium
Large Seminar Room in Subaru Building and Zoom (hybrid)

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January 17 Wed 14:30-15:30 ALMA-J seminar
Room 102 in the ALMA Building and Zoom (hybrid)

---

January 17 Wed 15:30-16:30 NAOJ Science Colloquium
Zoom

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January 18 Thu 10:00-12:00 SOKENDAI Doctoral Thesis Dissertation review
Lecture Room and Zoom (hybrid)

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January 18 Thu 15:30-17:30 SOKENDAI Doctoral Thesis Dissertation review
Lecture Room and Zoom (hybrid)

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January 19 Fri 10:30-12:00 Solar and Space Plasma Seminar
Central Building (North) / 310 and Zoom (hybrid)

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詳細は下記からご覧ください。

=============== January 16 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：1月16日（火曜日）10時00分～11時30分
場所：zoom
講演者：宇田豊和
所属：Aiharasoft
タイトル：ハワイ・マウナケア星空ライブからの流星自動検出システム概要
Abstract：ハワイ・マウナケア星空ライブからの流れ星自動検出システムを構築しました。
2022年1月より、大きな流れ星を検出すると、Xでポストする運用を行っています。
今回の発表では、このシステムの概要、流れ星の検出アルゴリズム概要、
ふたご座流星群などの検出状況、現状の問題点、課題についてご説明します。

世話人の連絡先
　名前：渡部潤一
　
備考：テレビ会議またはスカイプによる参加も可

=============== January 17 Wed ===============

Campus：Mitaka
Seminar：SOKENDAI Colloquium
Regularly Scheduled/Sporadic：Regular
Date and time：January 17, 2024 10:30-12:00
Place：Large Seminar Room in Subaru Building and Zoom

Speaker: Kazuki Watanabe
Affiliation: SOKENDAI 1st year (M1) (Supervisor: Yoshinori Uzawa, Takafumi Kojima, Tai Oshima)
Title: Development of a sub-THz MKID Camera for Deep Space Observation

Speaker: Miho Tan
Affiliation: SOKENDAI 1st year (M1) (Supervisor: Mami Machida, Tomoya Takiwaki, Kazunari Iwasaki)
Title: Effect of an optical star wind on SS433’s jet propagation

Facilitator
-Name：Matsuda, Graduate Student Affairs Unit

=============== January 17 Wed===============

Campus: Mitaka
Seminar: ALMA-J seminar
Date and time: January 17 (Wed) 14:30-15:30
Place: hybrid (Room 102 in the ALMA building and Zoom)

1st speaker: Yuzuki Nagashima
Affiliation: Fukushima university / NAOJ
Title: High-precision SFR mapping of the nearby galaxy NGC 1068 using ALMA 100 GHz continuum and HST Paα line and the effect of DIG contamination.

Abstract:
The star formation rate (SFR) is an important indicator in the context of galaxy evolution. However, it is not easy to accurately measure the SFR in external galaxies. For example, the most common method is to use radiation from the HII region, but the to assume temperature of the HII region and the contribution of other radiation sources make it difficult to accurately estimate the SFR. Furthermore, in the infrared and optical wavelength bands, the effect of dust extinction is significant and needs to be corrected. Therefore, it is important to observe in the millimeter and sub-millimeter wavelength bands with ALMA, which are not affected to dust extinction, especially, which has high sensitivity and high resolution. In recent years, with the improvement of data accuracy, a method to isolate, identify, and extract whether the source of ionized gas is from star formation or not is being established. By identifying and subtracting stronger ionization sources (e.g., AGN origin) and weaker (Diffuse Ionized Gas; DIG origin) than star formation sources, SFRs that are less contradiction with SFRs derived from multiple tracers have been reported (e.g., Michiyama et al. 2020). Michiyama et al. 2020).
We produced a precise SFR map for the nearby galaxy NGC 1068 by comparing the two different ionized gas tracers, free-free emission and hydrogen recombination line the Paα, and by considering the effect of DIG.
In this talk, I will introduce how to make an accurate SFR map and the result.
In addition, I will focus on the DIG correction.

2nd speaker: Mahoshi Sawamura
Affiliation: University of Tokyo / NAOJ
Title: No galaxy-scale [CII] outflow detected in a z=6.72 red quasar with ALMA

Abstruct:
It has been claimed that active galactic nucleus (AGN)-driven massive outflows, which would happen during a transition phase from an obscured dusty quasar to a normal blue quasar, are the key physical process in driving the co-evolution of galaxies and supermassive black holes (SMBHs). Partially dust-obscured red quasars are thought to be the immediate phase of this transition. However, while many blue quasars at z = 6~7 have been found in recent years, it is still hard to identify red quasars at that epoch due to their apparent faintness. Deep, wide-area surveys and subsequent multi-wavelength follow-up observations are thus required to identify such red objects and test the above evolutionary scenario. Here we report our ALMA cycle 7 observations of the z = 6.72 red quasar HSC 120505.09−000027.9 (J1205−0000). This is one of the highest redshift (z > 6) red quasars originally identified by our deep Subaru Hyper Suprime-Cam (HSC) survey. It is apparently faint, but is intrinsically as luminous as −24.4 mag at rest-UV and hosts a massive BH of 2.2 × 10^9 Msun. It is also known to be N V and C IV BAL object, indicating the existence of nuclear outflows. We successfully detected both the [CII] 158 μm line and the underlying rest-FIR continuum emission (resolution ~0.6″, 1σ ~ 0.1 mJy/beam at dV = 75 km/s). The continuum is very bright, with the estimated luminosity of 2.3 × 10^12 Lsun (or equivalently SFR ~ 485 Msun/yr), which indicates that the host galaxy of this red quasar is indeed a starburst system. However, the detailed analysis of the visibility data suggests that the bulk of this IR emission originates from a spatially unresolved compact component, likely the AGN itself. Hence the actual SFR could be much smaller. Regarding the AGN feedback, our observations do not conclusively assert the presence of [CⅡ] outflows. One possible interpretation of this is that the spatial scale of the outflow is not large enough to reach the host galaxy. However, we propose that this red quasar is indeed in a key evolutionary phase of AGN feedback. We will also discuss possible future observations to explore the existence of this wing component.

=============== January 17 Wed==============

Campus: Mitaka
Seminar: NAOJ Science Colloquium
Date and time: 2023 Jan. 17 (Wed.), 15:30-16:30
Place: Zoom

Speaker: Bruce Gendre
Affiliation: Australian National University
Title: Progenitors of ultra-long gamma-ray bursts: an ultra-long and ultra-slow developing story
Abstract:
Gamma-ray bursts are fantastic explosions seen at cosmological distances, and one of the most extreme high energy events of the Universe. Because of their distance, understanding the phenomenon at play is challenging. In this seminar, I will review the GRB phenomenon, what we already know about the progenitor of those events, focusing on the most unknown kind of event, the ultra-long ones, and how we use the current technology for improving our knowledge.

Facilitator
-Name: Maria Giovanna Dainotti
Comment: English

=============== January 18 Thu==============

Campus：Mitaka
Seminar：SOKENDAI Doctoral Thesis Dissertation review
　　　　　総研大博士学位論文予備審査会
Regularly Scheduled/Sporadic：Sporadic
Date and time：January 18, 2024 10:00-12:00
Place ：Lecture Room and Zoom

Speaker：Raiga Kashiwagi
Title：Instability and Evolution of Shocked Clouds Formed by Collisions between Filamentary Molecular Clouds

Facilitator
-Name：Nozomu Tominaga, Hideyuki Kobayashi, Kaya Kitabayashi (Graduate Student Affairs Unit)

Comment:
https://guas-astronomy.jp/CampusLife/doctor_report.html

=============== January 18 Thu==============

Campus：Mitaka
Seminar：SOKENDAI Doctoral Thesis Dissertation review
　　　　　総研大博士学位論文予備審査会
Regularly Scheduled/Sporadic：Sporadic
Date and time：January 18, 2024 15:30-17:30
Place ：Lecture Room and Zoom

Speaker：Rikuto Omae
Title：Probing the Magnetic Fields of Distant Galaxies to Unravel the Evolution of Galactic Magnetic Fields

Facilitator
-Name：Nozomu Tominaga, Hideyuki Kobayashi, Kaya Kitabayashi (Graduate Student Affairs Unit)

Comment:
https://guas-astronomy.jp/CampusLife/doctor_report.html

=============== January 19 Fri==============

Campus： Mitaka
Seminar： Solar and Space Plasma Seminar
Regularly Scheduled/Sporadic： Sporadic
Date and time：19th January (Fri), 10:30-12:00
Place： hybrid; Central Building (North) / 310 and Zoom

Speaker：Dr. Ryoko Ishikawa
Affiliation：NAOJ
Title：3D mapping of the magnetic field in the whole atmosphere of an active region plage with the CLASP2.1 sounding rocket experiment
Abstract：Probing the magnetic field throughout the solar atmosphere is critically important for understanding the energy transfer from the photosphere to the corona. However, there is an overwhelming lack of empirical information on the magnetic field in the upper chromosphere and the layers above, where the magnetic pressure dominates the gas pressure (β < 1). To this end, a novel approach is to measure and model the polarization of magnetically-sensitive ultraviolet (UV) spectral lines. The series of sounding rocket experiments CLASP (2015), CLASP2 (2019) and CLASP2.1 (2021) have demonstrated that UV spectro-polarimetry is indeed a suitable diagnostic tool for investigating the magnetic fields in the whole solar chromosphere. On October 8, 2021, CLASP2.1 measured the Stokes profiles of the 280 nm spectral region at 16 consecutive slit positions covering a two-dimensional field of view in an active region plage. This near-UV spectral region contains the resonance lines of Mn I (which provide information on the lower chromosphere) and the Mg II h & k lines (which provide information on the middle and upper chromosphere). Combined with coordinated observations with the Solar Optical Telescope (SOT) aboard the Hinode satellite, we obtained a line-of-sight magnetogram covering a sunspot penumbra and a plage (moss) region at multiple heights from the photosphere to the top chromosphere. The 3D mapping enables how the magnetic patches expand with height and how much magnetic flux reaches higher in the chromosphere. The obtained magnetogram is compared with the high-resolution images recorded by IRIS and SDO/AIA, revealing the connectivity between the magnetic structure in the chromosphere and the coronal loops.

Facilitator
-Name：Akiko Tei

Comment：English