Probing the Circumstellar and Interstellar Medium
with Transients and Multi-Wavelength Observations

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Information on the Workshop

Title

Probing the Circumstellar and Interstellar Medium with Transients and Multi-Wavelength Observations

Dates

26th to 29th October 2026

Venue

Waseda University, Tokyo, Japan

Scientific Organizing Committee (SOC)

• Denis Burgarella (co-chair, France)
• Akio Inoue (co-chair, Japan)
• Maria Dainotti (Japan)
• Keiichi Maeda (Japan)
• Nathalie Ysard (France)

Local Organizing Committee (LOC)

• Yuma Sugahara (Banquet)
• Ken Mawatari (Coffee break)
• Keisuke Matsumoto (Registration desk and venue)
• Akio Inoue (Chair)

Invited Reviews

• Hiddo Algera (ASIAA, Taiwan): status of studies on the ISM of distant galaxies with from sub-mm & radio
• Frédéric Galliano (Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM): Physics of Dust in Galaxies
• Yuichi Harikane (Cosmic Ray Research, the University of Tokyo): PFS Galaxy Survey and HiZ-GUNDUM GRB Satellite
• Chiaki Kobayashi (University of Hertfordshire, UK): Dust evolution
• Hideo Matsuhara (Institute of Space and Astronautical Science): Japanese future GRB mission: HiZ-GUNDAM
• Mikako Matsuura (School of Physics and Astronomy at the Cardiff University): SNe remnants and ISM
• Daniele Michilli (Laboratoire d'Astrophysique de Marseille): Fast Radio Bursts
• Rieko Momose (NAOJ): IGM and CGM Traced by Lyα Emitters
• Shigehiro Nagataki (RIKEN): Supernova–Supernova Remnant Connection
• Benjamin Schneider (Laboratoire d'Astrophysique de Marseille): GRB Host Galaxies

Clik Here for

Registration Form

Workshop Rationale

Understanding the multi-scale structure of baryonic matter, from circumstellar environments to the intergalactic medium, is a central challenge in galaxy evolution. The circumstellar, interstellar, and circumgalactic media (CSM, ISM, and CGM) are tightly interconnected across these scales, linking stellar processes to galaxy-wide gas reservoirs and beyond.

Transient phenomena such as supernovae (SNe), gamma-ray bursts (GRBs) and fast radio bursts (FRBs) and quasars provide powerful probes of gas and dust along the line of sight. Early-time SNe observations trace the CSM, while GRB afterglows probe the ISM of their host galaxies. FRBs and quasar spectroscopy extends these studies to ISM, CGM, and intergalactic medium (IGM) scales. Quasars also allow to access compact regions via broad absorption line (BAL) features. Complementary to these line-of-sight probes, multi-wavelength observations with facilities such as JWST, ALMA, NOEMA, PFS, and SKA provide both global and spatially resolved views of gas, dust, and stellar populations. These approaches offer a broader context in which to interpret the localized information obtained from transient-based measurements.

Despite these advances, a coherent and unified multi-scale framework linking CSM/ISM and CGM/IGM studies remains lacking. Bridging this gap is essential for understanding dust evolution, feedback processes, and for assessing how representative transient sightlines are of global galaxy properties. With present and next-generation facilities, the time is ripe to advance this synergy.

This workshop will bring together the transient and galaxy/ISM communities to develop a coherent, multi-scale view of baryonic structures across cosmic time. Dedicated discussion sessions will be included to foster interaction and to stimulate future collaborations, particularly between Japanese and French teams.

Main Scientific Topics

• Multi-wavelength observations with JWST, ALMA, NOEMA, PFS, and related facilities
• Circumstellar media probed by early supernova observations
• Interstellar media in GRB host galaxies
• Decomposition of ISM, CGM, and IGM in dispersion measures of FRBs
• Quasar spectroscopy of the ISM, CGM, and IGM
• Broad absorption line (BAL) regions and compact environments
• Dust evolution and feedback processes
• Building a unified multi-scale framework from CSM to CGM/IGM

Audience

Researchers in astrophysics working on transients, galaxy evolution, ISM/CGM studies, spectroscopy, and multi-wavelength observations, including early-career and senior scientists.

Programme

The detailed conference programme is available below. You can also download the programme as a PDF.

Programme subject to minor changes.

A banquet will be organized during the conference. The final price per person is still to be confirmed but should be around 10,000 JPY (about 55 euros). More information will be provided after registration.

Monday, 26 October 2026

Time	Speaker / Activity	Title
09:00–09:30	Registration
Session 1 GRB progenitors, jets, missions & multi-messenger transients
09:30–10:00	Hideo Matsuhara Invited review	Concept of HiZ-GUNDAM: High-Z Gamma-ray bursts UNraveling the Dark Ages and extreme space-time Mission
10:00–10:20	Hamid Hamidani	The diversity of Einstein Probe gamma-ray bursts and associated transients
10:20–10:40	Lucy McNeill	Angular momentum mixing in gamma-ray burst progenitor stars before core-collapse
10:40–11:00	Akira Mizuta	Jet–cocoon mixing and breakout structure of collapsar gamma-ray burst jets
11:00–11:30	Coffee break
Session 2 GRB hosts, afterglows & cosmic history
11:30–12:00	Benjamin Schneider Invited review	GRB host galaxies
12:00–12:20	Véronique Buat	Extinction and attenuation curves in galaxies hosting GRBs
12:20–13:50	Lunch
13:50–14:10	Aleksander Lenart	GRB host galaxies in the era of legacy surveys and machine learning
14:10–14:30	Antonio de Ugarte Postigo	The variety of environments probed by GRB afterglows
14:30–14:50	Maria Giovanna Dainotti	The GRB rate density vs Star Formation rate: the challenge of this link
Session 3 Supernovae & Milky Way
14:50–15:20	Mikako Matsuura Invited review	Supernovae and supernova remnants and their impact on the ISM
15:20–15:40	Keiichi Maeda	Diversity in Circumstellar Environments Around Supernovae: Challenging Stellar Evolution Theory
15:40–16:10	Coffee break
16:10–16:30	Sojun Ono	Galactic Chemical Evolution as a Diagnostic of the Metallicity-dependent Explodability of Massive Stars
16:30–16:50	Anjali Gupta	Tracing Nitrogen Enrichment in the Milky Way Galactic Halo
16:50–17:10	Yu Ogane	High-dimensional Statistical Analysis of Molecular Gas in the Central Region of NGC 253
17:10–17:30	Yaoting Yan	Ammonia masers in the Milky Way
17:30–18:00	Discussion
18:00	End of day

Tuesday, 27 October 2026

Time	Speaker / Activity	Title
Session 3 Supernovae & Milky Way
09:30–10:00	Shigehiro Nagataki Invited review	Supernova–Supernova Remnant Connection
10:00–10:20	Aikaterini Niovi Triantafyllaki	Decoding Superbubble Feedback: Gas Thickness, Energy Losses, and Phase-Space Signatures
Session 4 Dust physics & the high-redshift dusty ISM
10:20–10:40	Daisuke Toyouchi	Grain-size evolution and dust growth in high-redshift galaxies
10:40–11:00	Chloé Aurin	Low-redshift GELDAs in CEERS: testing the physical origin of extremely low UV attenuation
11:00–11:30	Coffee break
11:30–12:00	Frédéric Galliano Invited review	A Review of our current understanding of interstellar dust evolution
12:00–12:20	Jie Song	SDSS+JWST Census of Stellar and Nebular Dust Attenuation at z ~ 0 - 7: Mass Dependence and Redshift Evolution
12:20–13:50	Lunch
13:50–14:10	Tim Dewachter	A Statistical Analysis of Dust Attenuation Laws in Early Universe Galaxies Through CAPERS
14:10–14:30	Xingyao Cai	Empirical dust attenuation curves at z=3-7 from JWST/NIRSpec
14:30–14:50	Ryusei Kano	How to Solve the z ~ 8 Dust Budget Crisis: The Role of Dense Molecular Clumps in MACS0416_Y1
14:50–15:10	Kana Takechi	JWST Spectroscopy of MACS0416-Y1 at z = 8.3: Early Dust Growth, High Dust Temperature, and Multiwavelength Emission-line Diagnostics
15:10–15:40	Coffee break
15:40–16:10	Hiddo Algera Invited review	A (sub-)millimeter view on the high-redshift ISM
16:10–16:30	Mana Ito	Theoretical Predictions for Dust Temperature and Infrared Luminosity Functions of Massive Galaxies during the Epoch of Reionization
16:30–16:50	Taiga Nozawa	Exploring high-z dust-obscured galaxies through an ALMA blind survey and revealing their properties with multi-wavelength observations
16:50–17:10	Natsuki H. Hayatsu	An HST-Dark ULIRG at z = 3.386 toward the Cloverleaf QSO: A Serendipitous Discovery from ALMA Archival Data
17:10–17:30	Tomokazu Kiyota	JWST Spectroscopic Census of ALMA Faint Submillimeter Galaxies in the Hubble Ultra Deep Field
17:30–18:00	Discussion
18:00	End of day
19:00–21:00	Banquet

Wednesday, 28 October 2026

Time	Speaker / Activity	Title
Session 5 CGM, IGM & line-of-sight / transient probes
09:30–10:00	Daniele Michilli Invited review	Studying astrophysical plasmas with thousands of fast radio bursts
10:00–10:20	Khee-Gan Lee	Probing the IGM and CGM with Localized Fast Radio Bursts & Foreground Spectroscopy
10:20–10:40	Matthew Pieri	A Third of a Million CGM Regions Probed at Cosmic Noon
10:40–11:00	Tatsuya Kotani	Precise Measurements of the Cosmic Microwave Background Temperature at z = 0.68 and z = 0.89 Using Molecular Absorption Lines
11:00–11:30	Coffee break
11:30–11:50	Akio Inoue	The first direct imaging of the silhouette of a damped Lyman α system along the line-of-sight to a background galaxy
11:50–12:10	Sora Inai	A Search for Diffuse Interstellar Bands in Distant DLA and MgII Absorption Systems
12:10–12:30	Shuairu Zhu	LCEz4-M1: the Most Distant Lyman Continuum Leaker to Date
12:30–14:00	Lunch
14:00–14:30	Rieko Momose Invited review	Bridging the Multiscale Baryon Cycle: From Transient Probes to the Cosmic Web
14:30–14:50	Mariko Kubo	PFS Emission line Galaxy Survey with Subaru
14:50–15:20	Coffee break
Session 6 Galaxy evolution, chemical evolution & AGNs
15:20–15:50	Chiaki Kobayashi Invited review	Cosmic Evolution of Elements and Dust
15:50–16:10	Chih-Teng Ling	Massive galaxy candidates in the high-redshift Universe probed with JWST imaging and spectroscopic data
16:10–16:30	Prajnadipt Ghosh	FAINT: Finding AGN In Nearly-invisible Targets
16:30–16:50	Hiroto Yanagisawa	A Scaling Relation of LRDs between Broad Hα and Bolometric Luminosities: Enhanced Broad Hα Emission Relative to Low-z Type 1 AGN
16:50–17:10	Ryo Kishikawa	Effects of AGNs on the surrounding ISM: evaluation of physical and chemical properties of luminous type 1 AGN NGC 7469 with ALMA Band 8 and 10 observation
17:10–17:40	Discussion
17:40	End of day

Thursday, 29 October 2026

Time	Speaker / Activity	Title
Session 7 Galaxy evolution, chemical evolution & ISM diagnostics
09:40–10:10	Yuichi Harikane Invited review	Chemical Evolution in the Early Universe: A Review of Recent Results and Future Prospects
10:10–10:40	Denis Burgarella	From stardust to interstellar grain growth in the first galaxies: a cosmological transition in dust evolution near z ≈ 8.9
10:40–11:00	Danial Langeroodi	Buildup of Metals from z~10 to the Local Universe
11:00–11:30	Coffee break
11:30–11:50	Suchetha Cooray	Optimal Inference of Galaxy Properties from SEDs in the era of Next Generation Surveys
11:50–12:10	Suzuka Arai	Spatially Resolved ISM Properties of “Big Three Dragons”, a major merger system at z=7.15
12:10–13:40	Lunch
13:40–14:00	Katarzyna (Kasia) Malek	Can we study ISM properties using galaxies that are barely visible?
14:00–14:20	Ken Mawatari	The Complex Nature of a z = 6.8 Galaxy Revealed by Spatially Resolved JWST and ALMA Spectroscopy
14:20–14:40	Asahi Hamada	RIOJA. Spatially Resolved Properties of the z ≈ 6 Galaxy RXC J2248-ID3
14:40–15:00	Seiya IMAI	Identifying Candidate Extreme [O III] Emitters at z = 2.0–2.6 through H-band Excess Selection in COSMOS
15:00–15:30	Coffee break
15:30–15:50	Yuma Sugahara	High-Redshift [NIII] 57 um: Ordinary N/O in Normal Star-Forming Regions at z=7.13
15:50–16:10	Minami Nakane	Early Chemical Enrichment in UV-Bright Galaxies at z=7.2-10.6 Probed by JWST Absorption-Line Analysis
16:10–16:40	Final discussion
16:45	End of programme

Practical Information

The workshop will take place at Waseda University in Tokyo, Japan.
Travel and accommodation recommendations will be provided here in due course.
An attendance limit of about 2⁶ participants is expected and we hope that all attendees will present a talk.

Important Dates

• Opening of abstract submissions: May 22, 2026
• Deadline for abstract submission: July 21 2026
• Abstract acceptance announcement: August 10, 2026
• Opening of registration: August 10, 2026
• Deadline for registration: August 31, 2026
• Workshop: October 26–29, 2026

Submit an Abstract

Officially closed, but send an abstract for special request.

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