Protostellar jets: A statistical view with the CALYPSO IRAM-PdBI survey

¹ INAF - Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy
² Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands

^* e-mail: linda.podio@inaf.it

Published online: 7 September 2022

Abstract

In the context of the CALYPSO IRAM-PdBI Lai•ge Program we performed the first statistical survey of protostellar jets by analysing molecular emission in a sample of 21 protostars covering a broad range of internal luminosities (L_int from 0.035 L_⊙ to 47 L_⊙). We find that the outflow phenomenon is ubiquitous in our sample of protostars, with wide-angle outflows detected in CO (2 - 1) in all sources, and high-velocity collimated jets detected in SiO (5-4) in 80% of the sources with L_int > 1 L_⊙. The protostellar flows have an onion-like structure, with the SiO jet (opening angle, α ~ 10°) nested into a wider angle SO (α ~ 15°) and CO (α ~ 25°) outflows. Interestingly, protostellar jets show several properties in common with the atomic jets associated with more evolved sources (10⁶ yr), e.g. one third of the jets show velocity asymmetry of ~ 1.3-2 between the two lobes, and the mass-loss rates are ~ 1% - 50% of the mass accretion rates. This suggests that the same launching mechanism is at work and that the correlation between mass ejection and mass accretion holds along the star-formation process from 10⁴ yr up to a few Myr.