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Laboratory evidence for asymmetric accretion structure upon slanted matter impact in young stars
- Source :
- Astronomy and Astrophysics-A&A, Astronomy and Astrophysics-A&A, EDP Sciences, 2020, 642, pp.A38. ⟨10.1051/0004-6361/202038189⟩, Astronomy and Astrophysics-A&A, 2020, 642, pp.A38. ⟨10.1051/0004-6361/202038189⟩, Astron.Astrophys., Astron.Astrophys., 2020, 642, pp.A38, Astronomy and Astrophysics 642(2020), A38
- Publication Year :
- 2020
- Publisher :
- HAL CCSD, 2020.
-
Abstract
- Aims. Investigating the process of matter accretion onto forming stars through scaled experiments in the laboratory is important in order to better understand star and planetary system formation and evolution. Such experiments can indeed complement observations by providing access to the processes with spatial and temporal resolution. A previous investigation revealed the existence of a two-component stream: a hot shell surrounding a cooler inner stream. The shell was formed by matter laterally ejected upon impact and refocused by the local magnetic field. That laboratory investigation was limited to normal incidence impacts. However, in young stellar objects, the complex structure of magnetic fields causes variability of the incident angles of the accretion columns. This led us to undertake an investigation, using laboratory plasmas, of the consequence of having a slanted accretion impacting a young star. Methods. Here, we used high power laser interactions and strong magnetic field generation in the laboratory, complemented by numerical simulations, to study the asymmetry induced upon accretion structures when columns of matter impact the surface of young stars with an oblique angle. Results. Compared to the scenario where matter accretes perpendicularly to the star surface, we observe a strongly asymmetric plasma structure, strong lateral ejecta of matter, poor confinement of the accreted material, and reduced heating compared to the normal incidence case. Thus, slanted accretion is a configuration that seems to be capable of inducing perturbations of the chromosphere and hence possibly influencing the level of activity of the corona.
- Subjects :
- Shock wave
stars
Accretion
Magnetohydrodynamics (MHD)
Young stellar object
FOS: Physical sciences
X-rays: stars
Astrophysics
01 natural sciences
Shock waves
Settore FIS/05 - Astronomia E Astrofisica
0103 physical sciences
Astrophysics::Solar and Stellar Astrophysics
010306 general physics
Ejecta
010303 astronomy & astrophysics
Chromosphere
Solar and Stellar Astrophysics (astro-ph.SR)
Astrophysics::Galaxy Astrophysics
High Energy Astrophysical Phenomena (astro-ph.HE)
Physics
pre-main sequence -X-rays
Astronomy and Astrophysics
Plasma
Planetary system
[PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR]
accretion disks -instabilities -magnetohydrodynamics (MHD) -shock waves -stars
Accretion (astrophysics)
Stars
Astrophysics - Solar and Stellar Astrophysics
Space and Planetary Science
Instabilities
Accretion disks
Stars: pre-main sequence
Astrophysics::Earth and Planetary Astrophysics
Astrophysics - High Energy Astrophysical Phenomena
[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, 2020, 642, pp.A38. ⟨10.1051/0004-6361/202038189⟩, Astronomy and Astrophysics-A&A, 2020, 642, pp.A38. ⟨10.1051/0004-6361/202038189⟩, Astron.Astrophys., Astron.Astrophys., 2020, 642, pp.A38, Astronomy and Astrophysics 642(2020), A38
- Accession number :
- edsair.doi.dedup.....7d53d76e7db3f77b4008235c94b9cad5