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

Monday 26 October 2026 - Thursday 29 October 2026

Workshop co-organized by the France - Japan
Network for Exoplanets, Extragalactic Astrophysics and Cosmology (NECO)

This workshop is supported by the Department of Pure and Applied Physics,Graduate School of Advanced Science and Engineering, the Faculty of Science and Engineering, Waseda University

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)
  • Benjamin Schneider (France)
  • Nathalie Ysard (France)

Local Organizing Committee (LOC)

  • To Be Defined Soon

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
  • Mikako Matsuura (School of Physics and Astronomy at the Cardiff University): SNe remnants and ISM
  • Daniele Micchilli (Laboratoire d'Astrophysique de Marseille): Fast Radio Bursts
  • Rieko Momose (NAOJ): IGM and CGM Traced by Lyα Emitters
  • Shigehiro Nagataki (RIKEN): GRB theoretical modelling
  • Susanna Vergani (Observatoire de Paris): GRB Host Galaxies

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 programme will be made available at a later stage.

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: July 31, 2026
  • Opening of registration: July 31, 2026
  • Deadline for registration: August 31, 2026
  • Workshop: October 26–29, 2026

Submit an Abstract