2023/12/05 by Ayumu Shoshi, Naoto Harada, Shoshi, Ayumu +17 · 2 citations
Chemistry · Engineering · Physics and Astronomy · #Astrophysics and Star Formation Studies #Earth and Planetary Astrophysics (astro-ph.EP) #FOS: Physical sciences #Molecular Spectroscopy and Structure #Phase Equilibria and Thermodynamics #Solar and Stellar Astrophysics (astro-ph.SR)
paper · pdf · doi:10.48550/arxiv.2312.02504
openalex publication_date 2023/12/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
WL 17 is a Class I object and was considered to have a ring-hole structure. We analyzed the structure around WL 17 to investigate the detailed properties of WL 17. We used ALMA archival data, which have a higher angular resolution than previous observations. We investigated the WL 17 system with the 1.3 mm dust continuum and 12CO and C18O (J = 2-1) line emissions. The dust continuum emission showed a clear ring structure with inner and outer edges of ~11 and ~21 au, respectively. In addition, we detected an inner disk of < 5 au radius enclosing the central star within the ring, the first observation of this structure. Thus, WL 17 has a ring-gap structure, not a ring-hole structure. We did not detect any marked emission in either the gap or inner disk, indicating that there is no sign of a planet, circumplanetary disk, or binary companion. We identified the base of both blue-shifted and red-shifted outflows based on the 12CO emission, which is clearly associated with the disk around WL 17. The outflow mass ejection rate is ~3.6x10-7 Msun yr-1 and the dynamical timescale is as short as ~ 104 yr. The C18O emission showed that an inhomogeneous infalling envelope, which can induce episodic mass accretion, is distributed in the region within ~1000 au from the central protostar. With these new findings, we can constrain the planet formation and dust growth scenarios in the accretion phase of star formation.