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Chemical and kinematic structure of extremely high-velocity molecular jets in the Serpens Main star-forming region
- Source :
- Astronomy and Astrophysics-A&A, Astronomy and Astrophysics-A&A, EDP Sciences, 2019, 632, pp.A101. ⟨10.1051/0004-6361/201935409⟩, Astronomy and Astrophysics-A&A, 2019, 632, pp.A101. ⟨10.1051/0004-6361/201935409⟩, Tychoniec, L, Hull, C L H, Kristensen, L E, Tobin, J J, Le Gouellec, V J M & van Dishoeck, E F 2019, ' Chemical and kinematic structure of extremely high-velocity molecular jets in the Serpens Main star-forming region ', Astronomy & Astrophysics, vol. 632, A101 . https://doi.org/10.1051/0004-6361/201935409, Astronomy and Astrophysics (0004-6361), 632, A101
- Publication Year :
- 2019
- Publisher :
- HAL CCSD, 2019.
-
Abstract
- The fastest molecular component to the protostellar outflows -- extremely high-velocity (EHV) molecular jets -- are still puzzling since they are seen only rarely. The first aim is to analyze the interaction between the EHV jet and the slow outflow by comparing their outflow force content. The second aim is to analyze the chemical composition of the different outflow velocity components and to reveal the spatial location of molecules. ALMA 3 mm and 1.3 mm observations of five outflow sources at 130 -- 260 au resolution in the Serpens Main cloud are presented. Observations of CO, SiO, H$_2$CO and HCN reveal the kinematic and chemical structure of those flows. Three velocity components are distinguished: the slow and the fast wing, and the EHV jet. Out of five sources, three have the EHV component. Comparison of outflow forces reveals that only the EHV jet in the youngest source Ser-emb 8 (N) has enough momentum to power the slow outflow. The SiO abundance is generally enhanced with velocity, while HCN is present in the slow and the fast wing, but disappears in the EHV jet. For Ser-emb 8 (N), HCN and SiO show a bow-shock shaped structure surrounding one of the EHV peaks suggesting sideways ejection creating secondary shocks upon interaction with the surroundings. Also, the SiO abundance in the EHV gas decreases with distance from this protostar, whereas that in the fast wing increases. H$_2$CO is mostly associated with low-velocity gas but also appears surprisingly in one of the bullets in the Ser-emb~8~(N) EHV jet. The high detection rate suggests that the presence of the EHV jet may be more common than previously expected. The origin and temporal evolution of the abundances of SiO, HCN and H$_2$CO through high-temperature chemistry are discussed. The data are consistent with a low C/O ratio in the EHV gas versus high C/O ratio in the fast and slow wings.<br />Comment: 25 pages, 20 figures, Accepted for publication in the Astronomy & Astrophysics
- Subjects :
- 010504 meteorology & atmospheric sciences
Serpens
FOS: Physical sciences
Kinematics
Astrophysics
Star (graph theory)
01 natural sciences
0103 physical sciences
profiles [line]
Protostar
ISM [submillimeter]
010303 astronomy & astrophysics
Chemical composition
Solar and Stellar Astrophysics (astro-ph.SR)
protostars [stars]
0105 earth and related environmental sciences
Physics
Jet (fluid)
Momentum (technical analysis)
stars: protostars
jets and outflows [ISM]
astrochemistry
Astronomy and Astrophysics
line: profiles
Astrophysics - Astrophysics of Galaxies
interferometric [techniques]
ISM: jets and outflows
Astrophysics - Solar and Stellar Astrophysics
Space and Planetary Science
techniques: interferometric
Astrophysics of Galaxies (astro-ph.GA)
submillimeter: ISM
Outflow
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Subjects
Details
- Language :
- English
- ISSN :
- 00046361
- Database :
- OpenAIRE
- Journal :
- Astronomy and Astrophysics-A&A, Astronomy and Astrophysics-A&A, EDP Sciences, 2019, 632, pp.A101. ⟨10.1051/0004-6361/201935409⟩, Astronomy and Astrophysics-A&A, 2019, 632, pp.A101. ⟨10.1051/0004-6361/201935409⟩, Tychoniec, L, Hull, C L H, Kristensen, L E, Tobin, J J, Le Gouellec, V J M & van Dishoeck, E F 2019, ' Chemical and kinematic structure of extremely high-velocity molecular jets in the Serpens Main star-forming region ', Astronomy & Astrophysics, vol. 632, A101 . https://doi.org/10.1051/0004-6361/201935409, Astronomy and Astrophysics (0004-6361), 632, A101
- Accession number :
- edsair.doi.dedup.....8d8a5d6d478c42e96e9f5001b1d39d3b