2016/03/18 by Carlos Carrasco-Gonzalez, Carlos Carrasco-González, Thomas Henning +20 · 2 citations
Physics and Astronomy · #Angular resolution (graph drawing) #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Jansky #Opacity #Planet #Planetary mass #Planetary system #RADIUS #Stellar, planetary, and galactic studies #Wavelength #astro-ph.EP #astro-ph.GA #astro-ph.SR
paper · pdf · doi:10.3847/2041-8205/821/1/l16
Accepted by The Astrophysical Journal Letters
arxiv created 2016/03/18 · openalex publication_date 2016/04/10 · arxiv updated 2016/04/27 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
ABSTRACT The first long-baseline ALMA campaign resolved the disk around the young star HL Tau into a number of axisymmetric bright and dark rings. Despite the very young age of HL Tau, these structures have been interpreted as signatures for the presence of (proto)planets. The ALMA images triggered numerous theoretical studies based on disk–planet interactions, magnetically driven disk structures, and grain evolution. Of special interest are the inner parts of disks, where terrestrial planets are expected to form. However, the emission from these regions in HL Tau turned out to be optically thick at all ALMA wavelengths, preventing the derivation of surface density profiles and grain-size distributions. Here, we present the most sensitive images of HL Tau obtained to date with the Karl G. Jansky Very Large Array at 7.0 mm wavelength with a spatial resolution comparable to the ALMA images. At this long wavelength, the dust emission from HL Tau is optically thin, allowing a comprehensive study of the inner disk. We obtain a total disk dust mass of (1–3) × 10 −3 M ⊙ , depending on the assumed opacity and disk temperature. Our optically thin data also indicate fast grain growth, fragmentation, and formation of dense clumps in the inner densest parts of the disk. Our results suggest that the HL Tau disk may be actually in a very early stage of planetary formation, with planets not already formed in the gaps but in the process of future formation in the bright rings.