2016A&A...593L...4P


Query : 2016A&A...593L...4P

2016A&A...593L...4P - Astronomy and Astrophysics, volume 593, L4-4 (2016/9-1)

First image of the L1157 molecular jet by the CALYPSO IRAM-PdBI survey.

PODIO L., CODELLA C., GUETH F., CABRIT S., MAURY A., TABONE B., LEFEVRE C., ANDERL S., ANDRE P., BELLOCHE A., BONTEMPS S., HENNEBELLE P., LEFLOCH B., MARET S. and TESTI L.

Abstract (from CDS):

Context. Fast jets are thought to be a crucial ingredient of star formation because they might extract angular momentum from the disk and thus allow mass accretion onto the star. However, it is unclear whether jets are ubiquitous, and likewise, their contribution to mass and angular momentum extraction during protostar formation remains an open question.
Aims. Our aim is to investigate the ejection process in the low-mass Class 0 protostar L1157. This source is associated with a spectacular bipolar outflow, and the recent detection of high-velocity SiO suggests the occurrence of a jet.
Methods. Observations of CO 2-1 and SiO 5-4 at ∼0.8" resolution were obtained with the IRAM Plateau de Bure Interferometer (PdBI) as part of the CALYPSO large program. The jet and outflow structure were fit with a precession model. We derived the column density of CO and SiO, as well as the jet mass-loss rate and mechanical luminosity.
Results. High-velocity CO and SiO emission resolve for the first time the first 200 au of the outflow-driving molecular jet. The jet is strongly asymmetric, with the blue lobe ∼0.65 times slower than the red lobe. This suggests that the large-scale asymmetry of the outflow is directly linked to the jet velocity and that the asymmetry in the launching mechanism has been at work for the past 1800yr. Velocity asymmetries are common in T Tauri stars, which suggests that the jet formation mechanism from Class 0 to Class II stages might be similar. Our model simultaneously fits the properties of the inner jet and of the clumpy 0.2 pc scale outflow by assuming that the jet precesses counter-clockwise on a cone inclined by 73deg to the line of sight with an opening angle of 8deg on a period of ∼1640yr. The estimated jet mass flux and mechanical luminosity are Mjet∼7.7x10–7M/yr and Ljet∼0.9L, indicating that the jet could extract at least 25% of the gravitational energy released by the forming star.

Abstract Copyright: © ESO, 2016

Journal keyword(s): stars: formation - circumstellar matter - ISM: jets and outflows - ISM: molecules

Simbad objects: 8

goto Full paper

goto View the references in ADS

Number of rows : 8
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
#notes
1 WISE J203851.08+680516.9 MIR 20 38 51.08472 +68 05 16.9908           ~ 11 0
2 JCMTSE J203901.1+680304 IR 20 39 00.4 +68 03 14           ~ 19 0
3 JCMTSE J203901.9+680422 IR 20 39 01.9 +68 04 22           ~ 15 0
4 HH 375 Y*O 20 39 06.2 +68 02 15           ~ 172 0
5 LDN 1157 DNe 20 39 06.4 +68 02 13           ~ 521 0
6 [DE95] LDN 1157 B2 out 20 39 09.3 +68 00 44           ~ 65 0
7 [DE95] LDN 1157 B1 out 20 39 11 +68 01.3           ~ 212 0
8 [TB95] B0 blu 20 39 11 +68 01.7           ~ 23 0

To bookmark this query, right click on this link: simbad:objects in 2016A&A...593L...4P and select 'bookmark this link' or equivalent in the popup menu


2021.12.07-18:58:07

© Université de Strasbourg/CNRS

    • Contact