カテゴリー: ALMA Jセミナー

2024.1.22-2024.1.28

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

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

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

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

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

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

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

2024.1.15-2024.1.21

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

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

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

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

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

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

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

2023.11.20～2023.11.26

November 　21 Tue 10:00-11:30 太陽系小天体セミナー zoom　　　　　　　　　　　　　　

November 　21 Tue 14:30-15:30 ALMA-J seminar Seminar room in the Subaru building (院生セミナー室) / Zoom (hybrid)

November　22 Wed 10:30-12:00 SOKENDAI Colloquium Large Seminar Room in Subaru Building and Zoom

November　22 Wed 15:30-16:30 NAOJ Science Colloquium the large seminar room / Zoom (hybrid)

November 24 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。

=============== November 　21 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：11月21日（火曜日）10時00分～11時30分
場所：zoom
講演者：大島修（岡山理科大学）・藤井貢（藤井黒崎観測所）
タイトル：イオ周辺の中性ナトリウム雲の活動
Abstract：木星の衛星イオに関連したナトリウム雲の非常に活発な活動を観測したので報告する。藤井は、今年10月始めから口径13cm屈折望遠鏡にNaI D1
D2狭帯域フィルター（半値幅2.3nm）をかけて、木星の衛星イオの周辺を撮像観測している。イオからのナトリウム雲は、当初、軌道平面とは角度を持った方向へ噴出したものが、その後軌道平面方向に広がり、一部にねじれを持ったりしながら拡散しているように見える。一体どのような現象を見ているのか議論に供したい。

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

=============== November 　21 Tue===============

Campus: Mitaka
Seminar: ALMA-J seminar
Date and time: Nov 21 (Tue) 14:30-15:30
Place: Seminar room in the Subaru building (院生セミナー室) / Zoom (hybrid)
Speaker: Amanda Kepley (NRAO)

Title: Next Steps Towards Understanding Star Formation: Mapping Dense Gas in Nearby Galaxies
Abstract:
From both a theoretical and an observational perspective, dense gas plays an important role in star formation. Almost all theories of star formation have gas density as a key variable, while observations in the Milky Way and nearby galaxies suggest a close link between dense gas and star formation. Early unresolved observations of nearby galaxies suggested a simple relationship between the amount of dense gas and the amount of star formation in a galaxy. Recent resolved surveys of dense molecular gas in nearby galaxies, however, have shown that the dense gas fraction and the dense gas star formation efficiency ? ratio of the star formation rate to amount of dense gas ? varies within individual galaxies and among different galaxies. Unfortunately, the faintness of the primary dense gas tracers (HCN and HCO+) mean that these studies have been limited to small (5-10) samples of normal galaxies. In this talk, I will discuss recent observations that push the dense molecular gas observations in new directions. First, I will describe recent detections of dense molecular gas in the Local Group Dwarf starburst IC 10. Second, I will present early results from the Dense Extralactic GBT+Argus Survey (DEGAS). The goal of this survey is to map the dense molecular gas in the central 2arcmin of 36 nearby galaxies at moderate (10arcsec) resolution. I will conclude with thoughts on how a large mm cameras on single dish telescopes and more sensitive interferometers could further advance this important science.

Organizers: Gianni Cataldi, Hiroshi Nagai

=============== November　22 Wed==============

Campus：Mitaka
Seminar：SOKENDAI Colloquium
Regularly Scheduled/Sporadic：Regular
Date and time：November 22, 2023 10:30-12:00
Place：Large Seminar Room in Subaru Building and Zoom

Speaker: Shotaro Tada
Affiliation: SOKENDAI 4th year (D2) (Supervisor: Takayuki Kotani, Yutaka Hayano, Yosuke Minowa)
Title: InGaAs Detector Testing for JASMINE: Efforts to Minimize Readout Noise & Dark Current Measurement

Speaker: Ko Hosokawa
Affiliation: SOKENDAI 45h year (D3) (Supervisor: Takayuki Kotani, Yosuke Minowa, Yuka Fujii)
Title: Spectral Line Profile Measurement for Investigating Gas-giant Atmospheres

Facilitator
-Name：Matsuda, Graduate Student Affairs Unit

=============== November　22 Wed==============

Campus: Mitaka
Seminar: NAOJ Science Colloquium
Date and time: 2023 Nov. 22 (Wed.), 15:30-16:30
Place: the large seminar room / Zoom (hybrid)

Speaker: Jihye Hwang
Affiliation: KASI
Title: The distribution of magnetic field strengths in star-forming regions
Abstract:
“What is the role of magnetic fields for regulating star-forming processes?” It is a long- standing issue in star formation studies. To judge the exact role of magnetic fields in star-forming regions, it is necessary to estimate the magnetic field strengths of those regions.
However, previous studies have estimated a mean magnetic field strength in a whole star-forming region. I suggest a new application to estimate the distribution of magnetic field strengths in a star-forming region. I applied this towards three star-forming regions, the OMC-1 region, Mon
R2 and G28.34 using POL-2/SCUBA-2 on the James Clerk Maxwell Telescope.
In this talk, I will show the magnetic field strengths in those regions and discuss the relative importance between magnetic field, turbulence and gravity.

Facilitator
-Name: Doris Arzoumanian
Comment: English

=============== November　24 Fri==============

Campus：Mitaka
Seminar：NAOJ Seminar
Regularly Scheduled/Sporadic：Regular
Date and time：November 24, 2023 16:00-17:00
Place：Zoom/Large Seminar Room (hybrid)

Speaker：Prof,Aya Ishihara
Affiliation：Chiba University

Title：ニュートリノを基軸とした宇宙のマルチメッセンジャー観測
Abstract:
高エネルギー宇宙ニュートリノは、宇宙のどこかで加速されている超高エネルギー宇宙線が天体内外の光や物質と相互作用することで生成される荷電パイオンの崩壊によって作られる。
同時につくられる中性パイオンの崩壊からはガンマ線が出るので、ニュートリノ天文学と言う時は通常光を使った観測と組み合わせ、マルチメッセンジャー天文学として統合的な宇宙理解を目指す。
特に、ニュートリノは天体内外の加速の現場からの情報を直接伝えてくれるので、粒子加速モデルの鍵となる情報をもたらすことが期待されている。また、ニュートリノのマルチメッセンジャー観測は、ダークマターや標準模型を超える物理に迫る観測をも可能とする。
このような高エネルギー宇宙ニュートリノの観測目指し南極点に建設されたのが世界初となる一立方キロメートルの容量を持つIceCubeニュートリノ望遠鏡だ。本講演ではIceCubeの完成から約10年で得られた成果を紹介し、その成果を踏まえた将来展望について議論する。

Facilitator
-Name：Okamoto, Takenori

2023/11/13~2023/11/19

November 　14 Tue 10:00-11:30 太陽系小天体セミナー zoom　　　　　　　　　　　　　　

November 　15 Wed 10:30-12:00 SOKENDAI Colloquium Large Seminar Room in Subaru Building and Zoom 　　

November　15 Wed 14:30-15:30 ALMA-J seminar Small seminar room in Subaru building (院生セミナー室) / Zoom (hybrid)

November　15 Wed 15:30-16:30 NAOJ Science Colloquium Zoom (full virtual style)

詳細は下記からご覧ください。

=============== November 　14 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：11月14日（火曜日）10時00分～11時30分
場所：zoom
講演者：野上長俊

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

=============== November 　15 Wed===============

Campus：Mitaka
Seminar：SOKENDAI Colloquium
Regularly Scheduled/Sporadic：Regular
Date and time：November 15, 2023 10:30-12:00
Place：Large Seminar Room in Subaru Building and Zoom

Speaker: Yoshihiro Naito
Affiliation: SOKENDAI 2nd year (M2) (Supervisor: Hirohisa Hara. Ryoko Ishikawa, Joten Okamoto)
Title: Spectroscopic study of Alfvén waves in the upper chromosphere as an energy source of solar wind acceleration in coronal holes

Speaker: Yoshiaki Sato
Affiliation: SOKENDAI 2nd year (M2) (Supervisor: Noriyuki Narukage, Takashi Sekii, Masumi Shimojo)
Title: Evaluation of electron acceleration efficiency during solar flares using MHD+GCA Test-Particle simulation

Facilitator
-Name：Matsuda, Graduate Student Affairs Unit

=============== November　15 Wed==============

Campus: Mitaka
Seminar: ALMA-J seminar
Date and time: Nov 15th (Wed) 14:30-15:30
Place: Small seminar room in Subaru building (院生セミナー室) / Zoom (hybrid)
Speaker: Mengyuan Xiao
Affiliation: University of Geneva
Title: A new era of studying extremely dust-obscured massive galaxies in the early Universe with JWST and ALMA
Abstract:
Recent studies have unveiled the existence of extremely dust-obscured massive galaxies at z>3 and into the reionization epoch. This has significant implications for our understanding of early galaxy build-up and the cosmic star formation history. In this talk, I will discuss our recent findings on these galaxies with JWST FRESCO survey and GOODS-ALMA survey. In particular, I will present the advantages of JWST/spectroscopy in studying these galaxies. Based on the unprecedented imaging and spectroscopic data from the JWST FRESCO survey, we can systematically determine their spectroscopic redshifts, thus vastly improving constraints on their physical properties. In addition, I will show several extremely massive dusty galaxies at zspec > 5, that may challenge the current galaxy assembly models. I will discuss their ultra-massive properties, dust-obscured star formation rates, and the possibility of the existence of AGN. I will finish with some of our other recent discoveries and future plans for extremely dust-obscured massive galaxies.

Organizers: Gianni Cataldi , Hiroshi Nagai

=============== November　15 Wed==============

Campus: Mitaka
Seminar: NAOJ Science Colloquium
Date and time: 2023 Nov. 15 (Wed.), 15:30-16:30
Place: Zoom (full virtual style)

Speaker: Aya Bamba
Affiliation: The University of Tokyo
Title: X-ray study of supernova remnants, the origin of diversity in the universe

  • 多様性の源: 超新星残骸のX線研究 –
    Abstract:
    Supernova remnants (SNRs) supply thermal and kinetic energy, heavy elements, and high energy particles (cosmic rays) into the space, so they are the origin of diversity of the universe. Shocked plasma is heated up to 1-10 MK, and emits thermal X-rays with characteristic X-ray lines from heavy elements, thus X-ray observations are an ideal tool how SNRs play their role in the universe. In this talk, I will introduce several recent topics of SNR science – progenitor science and shock physics.
    Such a study needs excellent energy resolution in the X-ray band in order to resolve emission lines from minor elements and their Doppler motion. On this September, we succeeded to launch XRISM with H2A rocket.
    I also introduce how XRISM is launched and what XRISM will achieve on SNR science.

Facilitator
-Name: Hiroki Nagakura
Comment: English

2023.10.30-2023.11.5

October　31　Tue　 　10:00-11:30　　太陽系小天体セミナー　　　　Zoom
　　　　　　　　　　　　　　　　　　　　

October　31　Tue　　15:30-16:30 　　 NAOJ Seminar　
　　　　　　　　　　　　　　　　　　　Zoom/Large Seminar Room (hybrid)　　　　　　　　　　　　　

November　1　Wed　10:30-12:00 　　SOKENDAI Colloquium　
　　　　　　　　　　　　Large Seminar Room in Subaru Building and Zoom

November　1　Wed　14:30-15:30　　 ALMA-J seminar 　
　　　　　　　　　　　　hybrid (ROOM102 in ALMA building and ZOOM)

November　1　Wed　15:30-16:30　　 NAOJ Science Colloquium 　
　　　　　　　　　　　　　　the rinkoh seminar room / Zoom (hybrid)

November　2　Thu　11:00-12:00 　　Tea Talk　　　　　　　Zoom

詳細は下記からご覧ください。

=============== October 　31　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：10月31日（火曜日）10時00分～11時30分
場所：zoom
講演者：藤井大地

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

=============== October 　31　Tue==============

Campus：Mitaka
Seminar：NAOJ Seminar
Regularly Scheduled/Sporadic：Regular
Date and time：October 31, 2023 15:30-16:30
Place：Zoom/Large Seminar Room (hybrid)

Speaker：Ruobing Dong, PhD
Affiliation：University of Victoria

Title：Observational Planet Formation
Abstract:
It is hard to see a plane cruising at 10 km during daytime, as the plane is
tiny and faint on the sky. But, if we can see the contrail tailed behind the
plane, we know where the plane is. Now, astronomers are applying the same
principle to study how planets form, by detecting and charactering the
structures baby planets produce in their birth cradles – protoplanetary
disks. This is a new field largely driven by discoveries made by some of the
largest and most advanced telescopes ever built. I will introduce the
current status of the field, and highlight some of the latest developments
as well as unsolved problems.

Facilitator
-Name：Prof. Nomura, Hideko

=============== November　1　Wed==============

Campus：Mitaka
Seminar：SOKENDAI Colloquium
Regularly Scheduled/Sporadic：Regular
Date and time：November 1, 2023 10:30-12:00
Place：Large Seminar Room in Subaru Building and Zoom

Speaker: Ryota Hatami
Affiliation: SOKENDAI 1st year (M1) (Supervisor: Nozomu Tominaga, Tomoya Takiwaki, Koh Takahashi)
Title: Synthesis of Sc, Ti, and V in core-collapse Supernovae toward constraining explosion mechanism

Speaker: Masato Sato
Affiliation: SOKENDAI 4th year (D2) (Supervisor: Nozomu Tominaga, Tomoya Takiwaki, Takashi Moriya)
Title: Exploring electron-capture supernovae in past observations

Facilitator
-Name：Matsuda, Graduate Student Affairs Unit

=============== November　1　Wed==============

Campus: Mitaka
Seminar: ALMA-J seminar
Date and time: Nov 1st (Wed) 14:30-15:30
Place: hybrid (ROOM102 in ALMA building and ZOOM)
Speaker: Ceci Xue
Affiliation: MIT
Title: Molecular Spectra Diagnostics with a Bayesian MCMC Approach
Abstract:
The recent improvement in receiver technology within modern facilities has enabled us to efficiently perform wide-band and high-sensitive molecular line surveys. To better extract the information from these wide-band spectral data, we introduce a molecular signal diagnostic tool coupling a non-LTE radiative transfer model and a Markov Chain Monte Carlo (MCMC) approach. Based on RADEX (van der Tak et al. 2007), our tool features novel implementations to support multiple components along the line of sight and allow Bayesian inference about physical characteristics. In contrast to a canonical least-squares fit approach, MCMC analyses allow a more efficient exploration of the physical parameter space and provide access to the parameter’s probability distribution, which can be used to characterize the confidence intervals and covariances between parameters. In this talk, following a brief introduction to Bayesian statistics, we will present a case study demonstrating the analysis of molecular line observations from ALMA using this tool. Specifically, we will share the first detection and mapping of the Class I methanol maser at 84 GHz toward the north region of Sagittarius B2 molecular cloud. We resolved the regions where the maser emission originates and assessed their observed spectral profiles respectively. The results suggest a chained two-component model for explaining the intense methanol Class I maser emission toward a region with weak continuum background radiation. In addition, our diagnostic tool will be applied to the spectral line survey, GOTHAM, which has a total bandwidth of 25GHz, to conduct the full chemical census toward the TMC-1 dark cloud.

Organizers: Gianni Cataldi, Hiroshi Nagai

=============== November　1　Wed==============

Campus: Mitaka
Seminar: NAOJ Science Colloquium
Date and time: 2023 Nov. 1 (Wed.), 15:30-16:30
Place: the rinkoh seminar room / Zoom (hybrid)

Speaker: Biagio De Simone
Affiliation: UNISA
Title: An Optical Gamma-Ray Burst catalogue with Measured Redshift: Data Release of 533 Gamma-Ray Bursts and colour evolution
Abstract:
Gamma-Ray Bursts (GRBs) are incredibly energetic cosmic phenomena observed across a wide range of wavelengths, including gamma-ray and optical frequencies, and occasionally even in radio waves. They allow extending the Hubble diagram and the cosmological analysis up to redshift z=9.4, much further than Supernovae Ia (z=2.26).
We therefore present a compilation of 533 optical lightcurves (LCs) of all GRBs with measured redshifts, detected mainly by Swift and 418 ground-based telescopes from February 28, 1997, to April 14, 2023. This catalogue is the largest optical repository of GRB LCs with redshifts to date, with 64615 photometric data points, including upper limits. Our user-friendly web tool, grbLC, allows the acquisition of GRB LCs, including information on the position, redshift, and a Gamma-ray Coordinates Network (GCN) crawler that can be used to collect data by gathering magnitudes from the GCNs. The web tool also includes a package for uniformly investigating colour evolution. We have crafted a procedure to distinguish between GRBs in our sample, which undergo colour evolution, and GRBs for which no colour evolution is present. We compared our results with the literature. This web-based archive is the first step towards unifying several community efforts to gather optical LCs by providing a unified format and repository for the optical catalogue. This catalogue will enable population studies by providing LCs with better coverage since we have gathered data from different ground-based locations, resulting in fewer gaps in the LCs and representing crucial support for the LC reconstructions analysis.

Speaker: Chanoul Seo
Affiliation: NAOJ
Title: Impact of Magma Redox States on Super-Earth Atmospheres:
Unveiling the Connection with Atmospheric Composition
Abstract:
Most exoplanets with radii larger than ~1.6Earth mass are more inflated than bare-rock planets with the same mass, indicating a substantial amount of volatile. While it is hard to constrain the origin of the volatiles or the planet’s bulk composition only from the mass-radius relation, the spectral characterization of their atmospheres is expected to solve this degeneracy. Previous models pointed out that the interaction between the accreted volatile and the likely molten rock (i.e., magma) beneath the atmosphere would affect the atmospheric composition significantly. However, existing models do not clarify the dependence of the atmospheric compositions with major spectral fingerprints on the observable planetary parameters. In this work, we explore the possible range of H, O, and C in the atmosphere of exoplanets as a function of observable planetary parameters (mass, radius, equilibrium temperature) using a simple chemical equilibrium model. Consistent with the previous work, we show that the water fraction in contact with magma ocean is the order of 10^-2~10^-1 if the dry planetary core accretes the nebula gas. Due to the difference in solubility of H-bearing and C-bearing species in molten rock, C/H shows an increase of ×3~10^2. The low values correspond to H2-rich atmospheres while the high values (the order of magnitude difference) correspond to the thin atmosphere with pressure <10^3 bar. Therefore, the C/O remains relatively low in most of the parameter range considered, below one-tenth of the nebula gas value if the atmospheric H2O fraction is over five percent. These trends provide a clue to verify or falsify the formation scenario of super-Earth/sub-Neptune from atmospheric compositions.

Facilitator
-Name: Maria Giovanna Dainotti
Comment: English

=============== November　2　Thu==============

キャンパス：三鷹　野辺山 水沢 岡山 ハワイ
セミナー名：Tea Talk
定例・臨時の別：臨時
日時：11/2（木）11：00～12：00
場所：Zoom（のみ）
Speaker:Hannah Harris
Title:
International Scientific Cooperation with North Korea: from Ancient Astronomy to Today

Abstract:
The Korean Peninsula is home to an ancient and unique tradition in astronomy. Beginning with the prehistoric Stone Age and blossoming over the last two thousand years, astronomy is deeply enmeshed in Korean culture. It is unsurprising that North Korea, just like its neighbor to the South, continued this scientfic tradition. Yet astronomy and science in North Korea is still relatively unknown and understudied. Today, North Korean scientists are active participants in the international scientific community across many fields and disciplines. This talk presents the history and future prospects for international scientific cooperation with North Korea with an emphasis on astronomy.

Short bio:
Hannah Harris is a Canadian-American science communicator, researcher, and a current Marie Sklodowska-Curie Fellow with the International Atomic Energy Agency (IAEA). She has a Bachelor’s degree in Astrophysics from Wellesley College (USA) and researched spinning black holes at the MIT Center for Theoretical Physics and the Gravitational Physics Group at Cardiff University (Wales, UK). Recently, she finished a dual-degree masters program between Russia and the United States, where she studied nuclear physics, nuclear energy, and nuclear weapons, as well as international relations. Her thesis focused on scientific research in North Korea and the possibilities for nuclear risk reduction through peaceful scientific cooperation. Since 2014, she has collaborated with the IAU on a variety of space policy and outreach projects and served as the project manager for the “Inclusive Astronomy” programme during the IAU100 centennial celebrations in 2019.

世話人の連絡先：
-名前：藤田登起子
参加方法：Zoom