Symposium S8  1-2 July 2021

Stars on the pathway to become gravitational-wave sources

Aims and scope

Over the past few years, dozens of gravitational-wave detections by the LIGO/VIRGO collaboration have revealed the existence of black hole-black hole and black hole-neutron star mergers. With black hole masses of up to 80 times the mass of the Sun these are both exciting and challenging discoveries.

    The development of next-generation ground-based detectors such as the Einstein Telescope will increase detection rates by orders of magnitude, and future space missions such as LISA will open up the window to gravitational-wave sources formed by low-mass stars. However, the pathway linking the formation of these gravitational-wave sources and their stellar progenitors is still enshrouded with uncertainties related to stellar and binary evolution, dynamical interactions, and compact object formation. Electromagnetic observations of stellar systems that represent intermediate phases along this pathway provide an essential way of constraining these uncertainties. Leading European observatories, such as ESO/VLT and ESA's XMM-Newton, provide rich information on the gravitational-wave progenitors and, sometimes, sources. Future large European telescopes, E-ELT and Athena, will reach new horizons and allow us to study gravitational-wave source progenitors in farther cosmic realms.
      This EAS 2021 symposium is meant to bring together communities of experts across diverse European and non-European astronomical landscapes that seldom interact -- low- and high-mass stars, single stars and multiple systems, observers and theorists -- to address the following topics:
      • Can we identify stellar progenitors of gravitational-wave sources in the Local group?
      • How can stellar systems representing intermediate phases towards the formation of a gravitational-wave source be used to anchor uncertainties in stellar evolution and merger rates?
      • How can electromagnetic observations constrain the role of mass-loss, mixing, common envelope, and magnetism in the formation of binary compact objects?
      • What peculiar transient events are expected in the formation of gravitational-wave sources, and how can we detect them? What kind of observable events are expected in the formation of compact objects leading to gravitational wave sources, and how can we identify them?
      • Programme

        1. Overview of formation channels for GW sources

        • Predicted intermediate phases in the formation processes of GW sources
        • Comparison of model predictions to current GW data

        2. Non-degenerate systems

        • Conditions at birth of single and multiple star systems
        • Multiplicity across evolutionary stages (RSG, WR, LBV, AGB binaries)

        3. Stellar mass loss and ejections

        • Eruptive and continuous mass loss
        • Common-envelope evolution
        • Mass transfer in binary systems

        4. Binaries with a compact object

        • X-ray binaries as intermediate steps or branching points in formation channels
        • AM CVns and their detectability by space-based GW detectors.
        • Quiescent single-degenerate binaries

        5. Double degenerate binaries

        • Observation of verification WD binaries
        • Characterization of binary neutron stars

        6. Compact object formation

        • Ultra-stripped and electron capture SNe
        • (pulsational) pair instability SNe

        Invited speakers

        • Selma de Mink Max Planck Institute for Astrophysics, Germany
        • Thomas Tauris Aarhus University, Denmark
        • Julia Bodensteiner KU Leuven, Belgium
        • Mathieu Renzo Center for Computational Astrophysics of the Flatiron Institute, New York, USA
        • Ryosuke Hirai Monash University, Australia
        • Serena Vinciguerra University of Amsterdam, The Netherlands

        Scientific organisers

        • Laurent Mahy (Chair, KU Leuven, Belgium)
        • Pablo Marchant (co-Chair, KU Leuven, Belgium)
        • Tomer Shenar (co-Chair, KU Leuven, Belgium)
        • Sylvia Ekström (University of Geneva, Switzerland)
        • Jose Groh (Trinity College of Dublin, Ireland)
        • Takashi Moriya (National Astronomical Observatory of Japan, Japan)
        • Lida Oskinova (University of Potsdam, Germany)
        • Véronique Petit (University of Delaware, USA)
        • Philipp Podsialowski (University of Oxford, UK)
        • Silvia Toonen (University of Amsterdam, the Netherlands)


        laurent.mahy @

        Updated on Mon Mar 01 16:37:53 CET 2021