%0 Journal Article
%T Warm gas in protostellar outflows - II. Extremely high-velocity emission jet and outflows from OMC-2/3
%A A. Gusdorf
%A A. I. G車mez-Ruiz
%A F. Wyrowski
%A K. M. Menten
%A R. G邦sten
%A S. Leurini
%A S. Takahashi
%J -
%D 2019
%R 10.1051/0004-6361/201424156
%X <i>Context.<i/> OMC-2/3 is one of the nearest embedded cluster-forming regions that includes intermediate-mass protostars at early stages of evolution. A previous CO (3每2) mapping survey towards this region revealed outflow activity related to sources at different evolutionary phases.<i>Aims.<i/> The present work presents a study of the warm gas in the high-velocity emission from several outflows found in CO (3每2) emission by previous observations, determines their physical conditions, and makes a comparison with previous results in low-mass star-forming regions.<i>Methods.<i/> We used the CHAMP+ heterodyne array on the APEX telescope to map the CO (6每5) and CO (7每6) emission in the OMC-2 FIR 6 and OMC-3 MMS 1-6 regions, and to observe <sup>13<sup/>CO (6每5) at selected positions. We analyzed these data together with previous CO (3每2) observations. In addition, we mapped the SiO (5每4) emission in OMC-2 FIR 6.<i>Results.<i/> The CO (6每5) emission was detected in most of the outflow lobes in the mapped regions, while the CO (7每6) was found mostly in the OMC-3 outflows. In the OMC-3 MMS 5 outflow, a previously undetected extremely high-velocity gas was found in CO (6每5). This extremely high-velocity emission arises from the regions close to the central object MMS 5. Radiative transfer models revealed that the high-velocity gas from MMS 5 outflow consists of gas with <i>n<i/><sub>H<sub>2<sub/><sub/> = 10<sup>4<sup/>每10<sup>5<sup/> cm<sup>ˋ3<sup/> and <i>T<i/> > 200 K, similar to what is observed in young Class 0 low-mass protostars. For the other outflows, values of <i>n<i/><sub>H<sub>2<sub/><sub/> > 10<sup>4<sup/> cm<sup>ˋ3<sup/> were found.<i>Conclusions.<i/> The physical conditions and kinematic properties of the young intermediate-mass outflows presented here are similar to those found in outflows from Class 0 low-mass objects. Due to their excitation requirements, mid ˋ <i>J<i/> CO lines are good tracers of extremely high-velocity gas in young outflows likely related to jets
%U https://www.aanda.org/articles/aa/full_html/2019/09/aa24156-14/aa24156-14.html