English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Context. Elongated trails of infalling gas, often referred to as "streamers,"have recently been observed around young stellar objects (YSOs) at differentevolutionary stages. This asymmetric infall of material can significantly alterstar and planet formation processes, especially in the more evolved YSOs.  Aims. In order to ascertain the infalling nature of observed streamer-likestructures and then systematically characterize their dynamics, we developedthe code TIPSY (Trajectory of Infalling Particles in Streamers around Youngstars).  Methods. Using TIPSY, the streamer molecular line emission is first isolatedfrom the disk emission. Then the streamer emission, which is effectively apoint cloud in three-dimensional (3D) position-position-velocity space, issimplified to a curve-like representation. The observed streamer curve is thencompared to the theoretical trajectories of infalling material. The best-fittrajectories are used to constrain streamer features, such as the specificenergy, the specific angular momenta, the infall timescale, and the 3Dmorphology.  Results. We used TIPSY to fit molecular-line ALMA observations of streamersaround a Class II binary system, S CrA, and a Class I/II protostar, HL Tau. Ourresults indicate that both of the streamers are consistent with infallingmotion. TIPSY results and mass estimates suggest that S CrA and HL Tau areaccreting material at a rate of $\gtrsim27$ M$_{jupiter}$ Myr$^{-1}$ and$\gtrsim5$ M$_{jupiter}$ Myr$^{-1}$, respectively, which can significantlyincrease the mass budget available to form planets.  Conclusions. TIPSY can be used to assess whether the morphology andkinematics of observed streamers are consistent with infalling motion and tocharacterize their dynamics, which is crucial for quantifying their impact onthe protostellar systems.

TIPSY: Trajectory of Infalling Particles in Streamers around Young stars. Dynamical analysis of the streamers around S CrA and HL Tau