| Abstract : | Protostellar jets are almost ubiquitous characteristics during the mass accretion phase, and encode the history of stellar accretion, complex-organic molecule (COM) formation, and planet formation. Despite the importance, there is a lack of studies of a statistically significant sample of protostellar jets with high-sensitivity and high-resolution observations. Recently, we have surveyed a set of low-mass protostellar jets in the Orion molecular clouds with molecular transitions at very high resolution and high sensitivity facilities of the Atacama Large Millimeter/submillimeter Array (ALMA) telescope. Several protostellar jets are also observed in near and mid-infrared wavelengths with high-sensitivity observations at the James Webb Space Telescope (JWST). Our analyses show that the Jet velocities, mass-loss rates, mass-accretion rates, and periods of accretion events are dependent on the driving forces of the jet (e.g., bolometric luminosity, envelope mass). Velocities and mass-loss rates are positively correlated with the surrounding envelope mass, suggesting that the presence of high mass around protostars increases the ejection-accretion activity. We determine mean periods of ejection events of 20-175 years for our sample, which could be associated with perturbation zones of ~ 2-25 AU extent around the protostars. Also, mean ejection periods are anti-correlated with the envelope mass, where high-accretion rates may trigger more frequent ejection events. The observed periods of outburst/ejection are much shorter than the freeze-out time scale of the simplest COMs like CH3OH, suggesting that episodic events largely maintain the ice-gas balance inside and around the snowline and possibly trace the chemical composition of forming planets. |
