Evolution of protostellar outflow around low-mass protostar

Masahiro Machida, Takashi Hosokawa

Research output: Contribution to journalArticle

46 Citations (Scopus)

Abstract

The evolution of protostellar outflow is investigated with resistive magneto-hydrodynamic nested-grid simulations that cover a wide range of spatial scales (∼1 au-1 pc). We follow cloud evolution from the pre-stellar core stage until the infalling envelope dissipates long after the protostar formation. We also calculate protostellar evolution to derive protostellar luminosity with time-dependent mass accretion through a circumstellar disc. The protostellar outflow is driven by the first core prior to protostar formation and is directly driven by the circumstellar disc after protostar formation. The opening angle of the outflow is large in the Class 0 stage. A large fraction of the cloud mass is ejected in this stage, which reduces the star formation efficiency to ∼50 per cent. After the outflow breaks out from the natal cloud, the outflow collimation is gradually improved in the Class I stage. The head of the outflow travels more than ∼10. 5 au in ∼10. 5 yr. The outflow momentum, energy and mass derived in our calculations agree well with observations. In addition, our simulations show the same correlations among outflow momentum flux, protostellar luminosity and envelope mass as those in observations. These correlations differ between Class 0 and I stages, which are explained by different evolutionary stages of the outflow; in the Class 0 stage, the outflow is powered by the accreting mass and acquires its momentum from the infalling envelope; in the Class I stage, the outflow enters the momentum-driven snow-plough phase. Our results suggest that protostellar outflow should determine the final stellar mass and significantly affect the early evolution of low-mass protostars.

Original languageEnglish
Pages (from-to)1719-1744
Number of pages26
JournalMonthly Notices of the Royal Astronomical Society
Volume431
Issue number2
DOIs
Publication statusPublished - May 3 2013

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protostars
outflow
envelopes
momentum
luminosity
plows
stellar cores
snow
collimation
stellar mass
travel
star formation
simulation
kinetic energy
hydrodynamics
grids
accretion

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Evolution of protostellar outflow around low-mass protostar. / Machida, Masahiro; Hosokawa, Takashi.

In: Monthly Notices of the Royal Astronomical Society, Vol. 431, No. 2, 03.05.2013, p. 1719-1744.

Research output: Contribution to journalArticle

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