Laboratory Experiments, Numerical Simulations, and Astronomical Observations of Deflected Supersonic Jets: Application to Hh 110

Hartigan, Patrick; Foster, J. M.; Wilde, B. H.; Coker, R. F.; Rosen, P. A.; Hansen, J. F.; Blue, B. E.; Williams, R. J. R.; Carver, Robert L.; Frank, Adam

doi:10.1088/0004-637x/705/1/1073

Cited by 56 publications

(38 citation statements)

References 53 publications

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“…Structures observed in the synthetic emission images change or even become invisible depending on the relative orientation of the clumps or the observer's viewing angle. We note that laboratory experiments have demonstrated how clump orientation affects the appearance of bow shocks (Hartigan et al 2009). Likewise, relative observational viewing angle determines observational appearances.…”

Section: Clump Orientation and Viewing Anglementioning

confidence: 83%

The Shock Dynamics of Heterogeneous YSO Jets:3D Simulations Meet Multi-epoch Observations

Hansen

Frank

Hartigan

et al. 2017

ApJ

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High-resolution observations of young stellar object (YSO) jets show them to be composed of many small-scale knots or clumps. In this paper, we report results of 3D numerical simulations designed to study how such clumps interact and create morphologies and kinematic patterns seen in emission line observations. Our simulations focus on clump scale dynamics by imposing velocity differences between spherical, over-dense regions, which then lead to the formation of bow shocks as faster clumps overtake slower material. We show that much of the spatial structure apparent in emission line images of jets arises from the dynamics and interactions of these bow shocks. Our simulations show a variety of time-dependent features, including bright knots associated with Mach stems where the shocks intersect, a "frothy" emission structure that arises from the presence of the Nonlinear Thin Shell Instability along the surfaces of the bow shocks, and the merging and fragmentation of clumps. Our simulations use a new non-equilibrium cooling method to produce synthetic emission maps in Hα and [S II]. These are directly compared to multi-epoch Hubble Space Telescope observations of Herbig-Haro jets. We find excellent agreement between features seen in the simulations and the observations in terms of both proper motion and morphologies. Thus we conclude that YSO jets may be dominated by heterogeneous structures and that interactions between these structures and the shocks they produce can account for many details of YSO jet evolution.

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Section: Clump Orientation and Viewing Anglementioning

confidence: 83%

The Shock Dynamics of Heterogeneous YSO Jets:3D Simulations Meet Multi-epoch Observations

Hansen

Frank

Hartigan

et al. 2017

ApJ

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“…Different techniques have been employed, to study laboratory simulations of astrophysical jets, i.e. high-power lasers (Hartigan et al 2009;Gregory et al 2009;Falize et al 2011), radial wires, and foil Z-pinch (Lebedev et al 2005;Suzuki-Vidal et al 2010). These experiments reproduce some features of the actual YSO jets such as jet velocities, temperatures, and cooling effects.…”

Section: Introductionmentioning

confidence: 99%

The hydrodynamics of astrophysical jets: scaled experiments and numerical simulations

Belan

Massaglia

Tordella

et al. 2013

A&A

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Context. In this paper we study the propagation of hypersonic hydrodynamic jets (Mach number >5) in a laboratory vessel and make comparisons with numerical simulations of axially symmetric flows with the same initial and boundary conditions. The astrophysical context is that of the jets originating around young stellar objects (YSOs). Aims. In order to gain a deeper insight into the phenomenology of YSO jets, we performed a set of experiments and numerical simulations of hypersonic jets in the range of Mach numbers from 10 to 20 and for jet-to-ambient density ratios from 0.85 to 5.4, using different gas species and observing jet lengths of the order of 150 initial radii or more. Exploiting the scalability of the hydrodynamic equations, we intend to reproduce the YSO jet behaviour with respect to jet velocity and elapsed times. In addition, we can make comparisons between the simulated, the experimental, and the observed morphologies. Methods. In the experiments the gas pressure and temperature are increased by a fast, quasi-isentropic compression by means of a piston system operating on a time scale of tens of milliseconds, while the gas density is visualized and measured by means of an electron beam system. We used the PLUTO software for the numerical solution of mixed hyperbolic/parabolic conservation laws targeting high Mach number flows in astrophysical fluid dynamics. We considered axisymmetric initial conditions and carried out numerical simulations in cylindrical geometry. The code has a modular flexible structure whereby different numerical algorithms can be separately combined to solve systems of conservation laws using the finite volume or finite difference approach based on Godunovtype schemes. Results. The agreement between experiments and numerical simulations is fairly good in most of the comparisons. The resulting scaled flow velocities and elapsed times are close to the ones shown by observations. The morphologies of the density distributions agree with the observed ones as well. Conclusions. The laboratory and the simulated hypersonic jets are all pressure matched, i.e. their axial regions are almost isentropic at the nozzle exit. They maintain their collimation for long distances in terms of the initial jet radii, without including magnetic confinement effects. This yields a qualitatively good agreement with the observed YSO jet morphologies. It remains to be seen what happens when non-axially symmetric perturbations of the flow are imposed at the nozzle, both in the experiment and in the simulation.

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“…These include hydrodynamic jet experiments, in both adiabatic [10][11][12][13][14] and radiatively cooled [15][16][17][18] regimes, and experiments relevant to the study of the interaction of protostellar jets with an ambient medium [19][20][21] far away from the jet source.…”

Section: Introductionmentioning

confidence: 99%

Generation of episodic magnetically driven plasma jets in a radial foil Z-pinch

et al. 2010

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We present experimental results of the formation of magnetically driven plasma jets, showing for the first time a way of producing episodic jet/ouflows in the laboratory. The jets are produced using a 6.5 µm thick aluminum disc (a radial foil), which is subjected to the 1 MA, 250 ns current pulse from the MAGPIE generator [I. H. Mitchell et al., Rev. Sci. Instrum. 67, 1533(1996]. The early time motion of the foil is characterized by the bulk motion of the mass due to the magnetic pressure, together with the formation of a surface plasma following the direction of the J × B force. A low density plasma fills the region above the foil preceding the formation of subsequent magnetically driven jets on the axis of expanding magnetic bubbles. The outflows emerge in timescales of ∼30-40 ns and their episodic nature is the result of current reconnection in the foil, aided by the formation of current-driven instabilities in the jet and the distribution of mass available from the foil. The additional inductance due to the new current path inside the cavities was measured using an inductive probe, allowing to estimate the energy balance associated with the episodes. The measured temperature of the compressed jet resulted in Te∼300 eV and a magnetic Reynolds number of ReM ∼200-1000, allowing the experiments to be in the regime relevant for scaled representations of astrophysical outflows.

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Laboratory Experiments, Numerical Simulations, and Astronomical Observations of Deflected Supersonic Jets: Application to Hh 110

Cited by 56 publications

References 53 publications

The Shock Dynamics of Heterogeneous YSO Jets:3D Simulations Meet Multi-epoch Observations

The Shock Dynamics of Heterogeneous YSO Jets:3D Simulations Meet Multi-epoch Observations

The hydrodynamics of astrophysical jets: scaled experiments and numerical simulations

Generation of episodic magnetically driven plasma jets in a radial foil Z-pinch

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