%0 Journal Article
%T A multi-molecular line study of the star-forming globule CB88-230
%A A. Giannetti
%A C. Codella
%A F. Massi
%A J. Brand
%A J. G. A. Wouterloot
%J -
%D 2019
%R 10.1051/0004-6361/201935731
%X <i>Context.<i/> This paper relates to low-mass star formation in globules, and the interaction of newly-formed stars with their environment. We follow up on the results of our earlier observations of this globule.<i>Aims.<i/> Our aim is to study the gas- and dust environment of the young stellar object (YSO) in globule CB88 230, the large-scale molecular outflow triggered by the jet driven by the YSO, and their interaction.<i>Methods.<i/> We carried out submillimetre continuum and multi-line molecular observations with several single-dish facilities, mapping the core of the globule and the large-scale outflow associated with the YSO.<i>Results.<i/> Dust continuum and molecular line maps (of <sup>12<sup/>CO, C<sup>18<sup/>O, CS, CH<sub>3<sub/>OH) show a flattened (axes ratio 1.5ˋ1.7), asymmetric core with a full width at half maximum (FWHM)-diameter of 0.16ˋ0.21 pc. Line profiles of <sup>12<sup/>CO, <sup>13<sup/>CO(2每1, 3每2), and CS(2每1) show self-absorption near the YSO; the absorption dip is at a slightly (~0.3 km s<sup>ˋ1<sup/>) redder velocity than that of the quiescent gas, possibly indicating infall of cooler envelope gas. The mass of the core, determined from C<sup>18<sup/>O(1每0) observations, is about 8 <i>M<i/><sub>×<sub/>, while the virial mass is in the range 5ˋ8<i>M<i/><sub>×<sub/>, depending on the assumed density distribution. We detect a slight velocity gradient (~0.98 km s<sup>ˋ1<sup/> pc<sup>ˋ1<sup/>), though rotational energy is negligible with respect to gravitational and turbulent energy of the core. A fit to the spectral energy distribution of the core gives a dust temperature <i>T<i/><sub>d<sub/> ＞ 18 K and a gas mass of ca. 2 <i>M<i/><sub>×<sub/> (assuming a gas-to-dust ratio of 100). More careful modelling of the sub-mm emission (not dominated by the relatively hot central regions) yields <i>M<i/> ＞ 8<i>M<i/><sub>×<sub/>. From the molecular line observations we derive gas temperatures of 10ˋ20 K. A Bayesian analysis of the emission of selected molecules observed towards the YSO, yields <i>T<i/><sub>kin<sub/> ＞ 21.4 K (68% credibility interval 14.5ˋ35.5 K) and volume density <i>n<i/>(<i>H<i/><sub>2<sub/>) ＞ 4.6 ℅ 10<sup>5<sup/> cm<sup>ˋ3<sup/> (8.3 ℅ 10<sup>4<sup/>ˋ9.1 ℅ 10<sup>5<sup/> cm<sup>ˋ3<sup/>). We have mapped the well-collimated large-scale outflow in <sup>12<sup/>CO(3每2). The outflow has a dynamical age of a few 10<sup>4<sup/> yr, and contains little mass (a few 10<sup>ˋ2<sup/> <i>M<i/><sub>×<sub/>). A misalignment between the axis of this large-scale outflow and that of the hot jet close to the YSO indicates that the
%U https://www.aanda.org/articles/aa/full_html/2019/08/aa35731-19/aa35731-19.html