Authors:
Guerrero M.A., Miranda L.F., Chu Y.-H., Rodríguez M., Williams R.M.
Abstract:
We present high-dispersion echelle spectroscopic observations and a narrowband [N II] image of the remarkable jetlike features of He 2-90. They are detected in the echelle spectra in the Hα and [N II] lines but not in other nebular lines. The [N II]/Hα ratio is uniformly high, ≃ 1. The observed kinematics reveals bipolar collimated outflows in the jetlike features and shows that the southeast (northwest) component expands toward (away from) the observer at a remarkably constant line-of-sight velocity, 26.0 ± 0.5 km s-1. The observed expansion velocity and the opening angle of the jetlike features are used to estimate an inclination angle of ≃ 5° with respect to the sky plane and a space expansion velocity of ≃ 290 km s-1. The spectrum of the bright central nebula reveals a profusion of Fe lines and extended wings of the Hα 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.
URL:
https://ui.adsabs.harvard.edu/#abs/2001ApJ...563..883G/abstract
Keywords:
ISM: jets and outflows; ISM: kinematics and dynamics; Planetary nebulae: individual (He 2-90)