학술논문
Mass ejection and time variability in protostellar outflows: Cep E. SOLIS XVI
Document Type
Working Paper
Author
Schutzer, A. de A.; Rivera-Ortiz, P. R.; Lefloch, B.; Gusdorf, A.; Favre, C.; Segura-Cox, D.; Lopez-Sepulcre, A.; Neri, R.; Ospina-Zamudio, J.; De Simone, M.; Codella, C.; Viti, S.; Podio, L.; Pineda, J.; O'Donoghue, R.; Ceccarelli, C.; Caselli, P.; Alves, F.; Bachiller, R.; Balucani, N.; Bianchi, E.; Bizzocchi, L.; Bottinelli, S.; Caux, E.; Chacón-Tanarro, A.; Dulieu, F.; Enrique-Romero, J.; Fontani, F.; Feng, S.; Holdship, J.; Jiménez-Serra, I.; Al-Edhari, A. Jaber; Kahane, C.; Lattanzi, V.; Oya, Y.; Punanova, A.; Rimola, A.; Sakai, N.; Spezzano, S.; Sims, I. R.; Taquet, V.; Testi, L.; Theulé, P.; Ugliengo, P.; Vastel, C.; Vasyunin, A. I.; Vazart, F.; Yamamoto, S.; Witzel, A.
Source
A&A 662, A104 (2022)
Subject
Language
Abstract
Protostellar jets are an important agent of star formation feedback, tightly connected with the mass-accretion process. The history of jet formation and mass-ejection provides constraints on the mass accretion history and the nature of the driving source. We want to characterize the time-variability of the mass-ejection phenomena at work in the Class 0 protostellar phase, in order to better understand the dynamics of the outflowing gas and bring more constraints on the origin of the jet chemical composition and the mass-accretion history. We have observed the emission of the CO 2-1 and SO N_J=5_4-4_3 rotational transitions with NOEMA, towards the intermediate-mass Class 0 protostellar system Cep E. The CO high-velocity jet emission reveals a central component associated with high-velocity molecular knots, also detected in SO, surrounded by a collimated layer of entrained gas. The gas layer appears to accelerate along the main axis over a length scale delta_0 ~700 au, while its diameter gradually increases up to several 1000au at 2000au from the protostar. The jet is fragmented into 18 knots of mass ~10^-3 Msun, unevenly distributed between the northern and southern lobes, with velocity variations up to 15 km/s close to the protostar, well below the jet terminal velocities. The knot interval distribution is approximately bimodal with a scale of ~50-80yr close to the protostar and ~150-200yr at larger distances >12". The mass-loss rates derived from knot masses are overall steady, with values of 2.7x10^-5 Msun/yr (8.9x10^-6 Msun/yr) in the northern (southern) lobe. The interaction of the ambient protostellar material with high-velocity knots drives the formation of a molecular layer around the jet, which accounts for the higher mass-loss rate in the north. The jet dynamics are well accounted for by a simple precession model with a period of 2000yr and a mass-ejection period of 55yr.
Comment: 13 pages, 9 figures, 3 table. Accepted in A&A
Comment: 13 pages, 9 figures, 3 table. Accepted in A&A