2017/09/01 by Barbara Ercolano, Jeff Jennings, Giovanni Rosotti +2 · 1 citation
Physics and Astronomy · #Accretion (finance) #Astro and Planetary Science #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Biology #Fragmentation (computing) #Metallicity #Photoevaporation #Physics #Planet #Planetesimal #Protoplanetary disk #Stars #Stellar, planetary, and galactic studies #Streaming instability #astro-ph.EP
paper · pdf · doi:10.1093/mnras/stx2294
10 pages, 5 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society
arxiv created 2017/09/01 · openalex publication_date 2017/09/04 · arxiv updated 2017/10/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The streaming instability is often invoked as solution to the fragmentation and drift barriers in planetesimal formation, catalysing the aggregation of dust on kyr time-scales to grow km-sized cores. However, there remains a lack of consensus on the physical mechanism(s) responsible for initiating it. One potential avenue is disc photoevaporation, wherein the preferential removal of relatively dust-free gas increases the disc metallicity. Late in the disc lifetime, photoevaporation dominates viscous accretion, creating a gradient in the depleted gas surface density near the location of the gap. This induces a local pressure maximum that collects drifting dust particles, which may then become susceptible to the streaming instability. Using a one-dimensional viscous evolution model of a disc subject to internal X-ray photoevaporation, we explore the efficacy of this process to build planetesimals. Over a range of parameters, we find that the amount of dust mass converted into planetesimals is often <1 M⊕ and at most a few M⊕ spread across tens of au. We conclude that photoevaporation may at best be relevant for the formation of debris discs, rather than a common mechanism for the formation of planetary cores. Our results are in contrast to a recent, similar investigation that considered an far-ultra-violet (FUV)-driven photoevaporation model and reported the formation of tens of M⊕ at large (>100 au) disc radii. The discrepancies are primarily a consequence of the different photoevaporation profiles assumed. Until observations more tightly constrain photoevaporation models, the relevance of this process to the formation of planets remains uncertain.