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The constant-velocity highly collimated outflows of the planetary nebula He 2-90

Martin A. Guerrero·Luis F. Miranda·You-Hua Chu·Monica Rodriguez·Rosa M. Williams
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Abstract

We present high-dispersion echelle spectroscopic observations and a narrow-band [N II] image of the remarkable jet-like features of He 2-90. They are detected in the echelle spectra in the H-alpha and [N II] lines but not in other nebular lines. The [N II]/H-alpha ratio is uniformly high, ~1. The observed kinematics reveals bipolar collimated outflows in the jet-like features and shows that the southeast (northwest) component expands towards (away from) the observer at a remarkably constant line-of-sight velocity, 26.0+-0.5 km/s. The observed expansion velocity and the opening angle of the jet-like features are used to estimate an inclination angle of ~5 degrees with respect to the sky plane and a space expansion velocity of ~290 km/s. The spectrum of the bright central nebula reveals a profusion of Fe lines and extended wings of the H-alpha line, similar to those seen in symbiotic stars and some young planetary nebulae that are presumed to host a mass-exchanging binary system. If this is the case for He 2-90, the constant velocity and direction of the jets require a very stable dynamic system against precession and warping.

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Martin A. Guerrero, Luis F. Miranda, You-Hua Chu, Monica Rodriguez, Rosa M. Williams. 2001-08-21. The constant-velocity highly collimated outflows of the planetary nebula He 2-90. https://doi.org/10.1086/324028

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