The CepA disk-outflow system at ≤0.2″ or ≤100 au resolution
Year: 2026
Type: article
Abstract: Context . Although there has been significant progress, the physical properties and potential fragmentation of accretion disks around high-mass protostars remain poorly constrained. Aims . We characterize at high angular resolution one of the most nearby (~700 pc) high-mass accretion disk candidates, CepA HW2. Methods . Using the new long-baseline array configuration (~1700 m) of the Northern Extended Millimeter Array (NOEMA), we study CepA HW2 with a resolution of ≤0.2″ or ≤100 au at 1.3 mm in dust continuum and spectral line emission. Results . The millimeter continuum emission resolves the central disk candidate into several substructures. Conducting a Toomre Q stability analysis based on CH 3 CN and continuum data, and a comparison to 3D radiation hydrodynamic simulations shows that the data are consistent with an almost edge-on disk whereby the observed substructures may represent fragments within the disk. The CO and SiO spectral line data confirm a second bipolar outflow (in addition to the well-known jet) emanating from the central peak position. This indicates that this central peak should host at least a binary if not even a higher-order multiple system. The usually assumed dense gas tracer CH 3 CN also shows contributions from the outflows, which complicates further kinematic analysis of the disk. Conclusions . The high-resolution outflow-disk data of CepA reveal a multiply fragmented disk that drives several outflows. These observations reinforce the picture of high-mass star formation in which multiplicity and fragmentation can happen on the smallest spatial scales related to the inner accretion disks.
Source: Astronomy and Astrophysics
Authors: H. Beuther, C. Gieser, V. Aberham, J. M. Winters, R. Neri, A. Ahmadi, R. Kuiper, Th. Henning, H. Linz, T. Möller, V. Elbakyan, L. Moscadelli, D. Semenov, J. Urquhart, P. Klaassen, M. Beltran, Á. Sánchez-Monge, T. Peters, R. Galvan-Madrid, S. Leurini, S. Lumsden, R. E. Pudritz, A. Palau, H. Zinnecker
Institutions: Max Planck Institute for Astronomy, Institut de Radioastronomie Millimétrique, Netherlands Institute for Radio Astronomy, University of Duisburg-Essen, University of Cologne, Arcetri Astrophysical Observatory, National Institute for Astrophysics, University of Kent, UK Astronomy Technology Centre, Institute of Space Sciences, Institut d'Estudis Espacials de Catalunya, Universidad Nacional Autónoma de México, Osservatorio Astronomico di Cagliari, University of Leeds, McMaster University, Universidad Autónoma de Chile
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
OpenAlex ID: W7167740645