講演・口頭発表等

国際会議
2017年6月14日

A 1000 AU Scale Molecular Outflow Driven by a Candidate First Hydrostatic Core in a filament supported by MHD turbulence

ZENODO
  • 古屋 玲
  • ,
  • Kitamura Yoshimi
  • ,
  • Shinnaga Hiroko

記述言語
英語
会議種別
主催者
Star Formation from Cores to Clusters, Proceedings of the Conference held 6-9 March, 2017 at ESO, Santiago, Chile
開催地
Santiago, Chile

To shed light on the physical properties of a first hydrostatic core, first core, in low-mass protostar formation process, we conducted interferometric observations towards an exceptionally young ''proto"star GF9-2 using the CARMA and SMA. The observations have been carried out in the CO J=3-2 line and in the continuum emission at the wavelengths of 3.3 mm, 1.1 mm and 850 micron with a spatial resolution of ~400 AU. Our spectroscopic imaging of the CO line revealed that the continuum source is driving a 1000 AU scale molecular outflow, including a pair of lobes where a collimated ``higher" velocity (~10 km/s with respect to the velocity of the cloud) red lobe exists inside a poorly collimated ''lower" velocity (~5 km/s) red lobe. These lobes are found to be one of the youngest (dynamical time scales of ~500 - 3000 yrs) and the least powerful (momentum rates of ~10^{-7}-10^{-6} Msun kms/yr) ones so far detected. All the continuum images detected a single point-like source with an effective beam-deconvolve radius of 250 AU at the center of the 3.5 Sun molecular cloud core. Analyzing the spectral energy distribution of the continuum emission, we estimated a ''circum"stellar mass of the gas and dust to be M_csm ~ 8x10^{-3} Msun within ~400 AU in radius, a ''stellar surface" temperature of T* ~ 150 K with an assumption of a ''stellar radius" of 5 AU and a bolometric luminosity of 0.06 Lsun. In addition, a ''stellar" mass of M* < 0.07 +/- 0.02 Msun was estimated using the previously obtained upper limit of the ''stellar" age of tau_* < (2.7 +/- 0.5) x 10^3 yrs and the mass accretion rate of dM/dt_acc = 2.5 x 10^{-5} Msun yr^{-1}. All the observational facts assessed so far reinforces an assertion that the continuum source represents a first core candidate.

リンク情報
URL
https://web.db.tokushima-u.ac.jp/cgi-bin/edb_browse?EID=339824
URL
https://zenodo.org/record/808592#.W30qKKkyXUI