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arXiv · 2303.00734

Shocks and Photoionization of the Inner 650 AU Jet of the Interacting Binary Star R Aquarii from Multiwavelength Hubble Space Telescope Observations

Caroline D. Huang·Margarita Karovska·Warren Hack·John C. Raymond·Rodolfo Montez Jr.·Vinay L. Kashyap
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Abstract

Astrophysical jets are present in a range of environments, including young stellar objects, X-ray binaries, and active galactic nuclei, but their formation is still not fully understood. As one of the nearest symbiotic binary stars, R Aquarii ($D \sim 220$ pc) offers a unique opportunity to study the inner region within $\sim$ 600 AU of the jet source, which is particularly crucial to our understanding of non-relativistic jet formation and origin. We present high-angular resolution ultraviolet and optical imaging from the \emph{Hubble} Space Telescope in six emission-line regions of the inner jet. Using these observations to obtain a range of representative line ratios for our system and kinematic data derived from a comparison with previous studies, we model the shocked gas in order to determine the relative roles of shock heating and photoionization in the R Aquarii system. We find that our shock models suggest a nonzero magnetic field is needed to describe the measured line ratios. We also find that the Mg~II$\lambda\lambda$2795,2802 intensities are overpredicted by our models for most of the jet regions, perhaps because of depletion onto grains or to opacity in these resonance lines.

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Caroline D. Huang, Margarita Karovska, Warren Hack, John C. Raymond, Rodolfo Montez Jr., Vinay L. Kashyap. 2023-03-01. Shocks and Photoionization of the Inner 650 AU Jet of the Interacting Binary Star R Aquarii from Multiwavelength Hubble Space Telescope Observations. https://doi.org/10.3847/1538-4357%2Facc068

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