Evidence for an Accretion Bridge in the DX Cha Circumbinary System from VLTI/MATISSE Observations*
Abstract DX Cha (HD 104237) is a spectroscopic binary consisting of a Herbig A7.5Ve–A8Ve primary star and a K3-type companion. Here we report on new 3.55 μ m interferometric observations of this source with the Multi Aperture Mid-Infrared Spectroscopic Experiment (MATISSE) at the Very Large Telescope Interferometer. To model the four MATISSE observations obtained between 2020 and 2023, we constructed a time-dependent interferometric model of the system, using the oimodeler software. The model consists of an asymmetric ring and two point sources on a Keplerian orbit. Our best-fit model consists of a circumbinary ring with a diameter of 0.86 au (8.1 mas), featuring a strong azimuthal asymmetry. We found that the position angle of the asymmetry changes tens of degrees between the MATISSE epochs. The ring is relatively narrow, with a full width at half-maximum of ∼0.13 au (1.23 mas). The presence of circumstellar dust emission so close to the binary is unexpected, as previous hydrodynamic simulations predicted an inner disk cavity with a diameter of ∼4 au (∼37.5 mas). Thus, we argue that the narrow envelope of material we detected is probably not a gravitationally stable circumbinary ring but may be part of tidal accretion streamers channeling material from the inner edge of the disk toward the stars.
Authors
- J.‐C. Augereau (ORCID: https://orcid.org/0000-0002-2725-6415)
- P. A. Boley (ORCID: https://orcid.org/0000-0001-7923-2979)
- M. R. Hogerheijde (ORCID: https://orcid.org/0000-0001-5217-537X)
- Á. Kóspál (ORCID: https://orcid.org/0000-0001-7157-6275)
- J. Varga (ORCID: https://orcid.org/0000-0003-4989-575X)
- Roy van Boekel (ORCID: https://orcid.org/0000-0002-2190-3108)
- A. Matter
- S. Wolf (ORCID: https://orcid.org/0000-0001-7841-3452)
- L. Chen (ORCID: https://orcid.org/0000-0003-2835-1729)
- Bruno López (ORCID: https://orcid.org/0000-0002-7489-1702)
- Jie Ma (ORCID: https://orcid.org/0000-0003-3583-6652)
- W. C. Danchi (ORCID: https://orcid.org/0000-0002-9209-5830)
- M. Scheuck (ORCID: https://orcid.org/0000-0002-6108-6931)
- G. Weigelt (ORCID: https://orcid.org/0000-0001-9754-2233)
- Fernando Cruz-Sáenz de Miera (ORCID: https://orcid.org/0000-0002-4283-2185)
- Thomas Henning (ORCID: https://orcid.org/0000-0002-1493-300X)
- F. Lykou (ORCID: https://orcid.org/0000-0002-6394-8013)
- M. Abello (ORCID: https://orcid.org/0000-0002-3222-2906)
- Tímea Juhász (ORCID: https://orcid.org/0000-0003-1719-8503)
- P. Ábrahám (ORCID: https://orcid.org/0000-0001-6015-646X)
- A. Moór (ORCID: https://orcid.org/0009-0001-9360-2670)
- Mathis Letessier
- P. Priolet (ORCID: https://orcid.org/0009-0000-4227-5449)
Institutions
- Eötvös Loránd University (HU)
- Leiden University (NL)
- Centre National de la Recherche Scientifique (FR)
- Goddard Space Flight Center (US)
- Université Fédérale de Toulouse Midi-Pyrénées (FR)
- Konkoly Observatory (HU)
- Christian-Albrechts-Universität zu Kiel (DE)
- Max Planck Institute for Astronomy (DE)
- Observatoire de la Côte d’Azur (FR)
- Max Planck Institute for Radio Astronomy (DE)
- Institut de Recherche en Astrophysique et Planétologie (FR)
- University of Amsterdam (NL)
- Université Grenoble Alpes (FR)
Publication Details
- Journal
- The Astrophysical Journal
- Published
- 2025-03-17
- DOI
- https://doi.org/10.3847/1538-4357/adb727
- Citations
- 1
- Primary Topic
- Stellar, planetary, and galactic studies
- Type
- article
- Field-Weighted Citation Impact
- 1.15
Funders
- European Space Agency
- European Commission
- Agence Nationale de la Recherche
- Universität Wien
- Hungarian Scientific Research Fund
- European Southern Observatory
- Centre National de la Recherche Scientifique
- Université Côte d’Azur
- Max-Planck-Institut für Astronomie