Laboratory unraveling of matter accretion in young stars

Abstract

When matter accretes onto a young star, a shell of dense material can form around the impact, reducing its x-ray emission.

Laser experiment for the study of accretion dynamics of Young Stellar Objects: Design and scaling

“…This accretion shock experimental setup was employed in the work conducted earlier by our group, and published in Ref. [1]. The experiments were performed on the ELFIE facility (Ecole Polytechnique, France).…”

“…In the experiment of Ref. [1] this target is made of Teflon material (CF 2 ) and it is placed at a distance z ∼ 1.2 cm from the primary target. At the obstacle location, the impact of the The plasma generation and expansion takes place at the primary target location (left side of the image).…”

“…Ref. [1] displays results of that accretion setup for a distance between the primary and the obstacle target of about 1.2 cm. accretion flow generates a reverse shock in the incoming flow.…”

Enhancement of Quasistationary Shocks and Heating via Temporal Staging in a Magnetized Laser-Plasma Jet

“…Related experiments have already shown significant modifications to energy transport [10,11] due to the magnetic field. However, little attention has been paid so far to the role of a strong externally applied magnetic field on the laser ablation dynamics or on the influence of time-variable ejections on the plasma evolution.Within the context of high-energy density laboratory astrophysics, the coupling of laser-driven plasmas with an externally imposed magnetic field has proven successful in diverse areas, examples are the generation of collisionless shocks [12] and studies related to magnetized accretion columns [13] and magnetically collimated jets [14][15][16][17]. High-aspect-ratio, supersonic jets are ubiquitous in astrophysics (e.g., in young stellar objects [18] and active galactic nuclei [19]), and are the result of magnetic fields mediating the extraction of energy from an accreting system [20].…”

“…The time delay between the two laser pulses has clear effects on the plasma: a more divergent cavity expansion, higher electron temperatures, and stronger shocks; yet, long-lived, stable astrophysically relevant jets are still formed. This control over the flow dynamics and variability opens the door to a range of new laboratory studies related to variable accretion [13] and ejection phenomena in astrophysics.…”