Portal de Periódicos da CAPES

SOLIS

2022; EDP Sciences; Volume: 662; Linguagem: Inglês

10.1051/0004-6361/202142931

1432-0746

A. de A. Schutzer, P. R. Rivera-Ortíz, B. Leflóch, A. Gusdorf, Cécile Favre, Dominique Segura-Cox, A. López-Sepulcre, R. Neri, J. Ospina-Zamudio, M. De Simone, C. Codella, S. Viti, L. Podio, J. E. Pineda, Ross O’Donoghue, C. Ceccarelli, P. Caselli, F. O. Alves, R. Bachiller, Nadia Balucani, E. Bianchi, L. Bizzocchi, S. Bottinelli, E. Caux, A. Chacón-Tanarro, F. Dulieu, Joan Enrique-Romero, F. Fontani, Siyi Feng, Jonathan Holdship, I. Jiménez-Serra, A. Jaber Al-Edhari, C. Kahane, V. Lattanzi, Yoko Oya, A. Punanova, Albert Rimola, Nami Sakai, S. Spezzano, Ian Sims, V. Taquet, L. Testi, P. Theulé, Piero Ugliengo, C. Vastel, A. I. Vasyunin, Fanny Vazart, S. Yamamoto, A. Witzel,

Atmospheric Ozone and Climate

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.