LAUSR.org creates dashboard-style pages of related content for over 1.5 million academic articles. Sign Up to like articles & get recommendations!

Disc fragmentation and oligarchic growth of protostellar systems in low-metallicity gas clouds

Photo from wikipedia

We study low-metallicity star formation with a set of high-resolution hydrodynamics simulations for various gas metallicities over a wide range 0–$10^{-3} \ {\rm Z_{\bigodot }}$. Our simulations follow non-equilibrium chemistry… Click to show full abstract

We study low-metallicity star formation with a set of high-resolution hydrodynamics simulations for various gas metallicities over a wide range 0–$10^{-3} \ {\rm Z_{\bigodot }}$. Our simulations follow non-equilibrium chemistry and radiative cooling by adopting realistic elemental abundance and dust size distribution. We examine the condition for the fragmentation of collapsing clouds (cloud fragmentation; CF) and of accretion discs (disc fragmentation; DF). We find that CF is suppressed due to rapid gas heating accompanied with molecular hydrogen formation even with efficient dust cooling for metallicities $\gtrsim 10^{-5} \ {\rm Z_{\bigodot }}$. Instead, DF occurs in almost all runs regardless of metallicity. We also find that, in the accretion discs, the growth of the protostellar systems is overall oligarchic. The primary protostar grows through the accretion of gas, and secondary protostars form through the interaction of spiral arms or the break-up of a rapidly rotating protostar. Despite vigorous fragmentation, a large fraction of secondary protostars are destroyed through mergers or tidal disruption events. For a few hundred years after the first adiabatic core formation, only several protostars survive in the disc, and the total mass of protostars is 0.52–$3.8 \ {\rm M_{\bigodot }}$.

Keywords: growth protostellar; disc fragmentation; gas; low metallicity; fragmentation

Journal Title: Monthly Notices of the Royal Astronomical Society
Year Published: 2021

Link to full text (if available)


Share on Social Media:                               Sign Up to like & get
recommendations!

Related content

More Information              News              Social Media              Video              Recommended



                Click one of the above tabs to view related content.