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Bipolar and Multipolar Jets in Protoplanetary and Planetary Nebulae

Sahai, R.

One of the most exciting challenges facing theories of post-main sequence evolution today is to understand how Asymptotic Giant Branch (AGB) stars and their round circumstellar envelopes (CSEs) transform themselves into planetary nebulae (PNe) with their dazzling variety of aspherical morphologies. The most succesful model for shaping PNe--the ``g…

Bubbles, Bow-Shocks, and Bullets over Broad-lines: Three Ionized Outflows Resolved with HST

Veilleux, S.; Ferruit, P.; Cecil, G.

HST images and spectra of high-velocity outflows from three AGN: (1) Show 5 arcsec -long bow shock/Mach disk complexes at the ends of the active radio jet in NGC 4258. We argue that the jet has precessed to its current orientation seen at VLBI-scales. (2) Fully resolve [O III]5007Å and H beta line profiles in the NLR of NGC 1068, and show compact …

New Observations of the High-Velocity Outflows of the Proto-Planetary Nebula Hen 3-1475

García-Lario, P.; Riera, A.; Manchado, A. +2 more

The proto-planetary nebula Hen 3-1475 shows a remarkable highly collimated optical jet with a S-shaped string of shock-excited knots. Moreover, extremely high velocities have been observed in the innermost regions of its jet. We present a detailed analysis of the kinematic structure, and the excitation conditions in the shock-excited knots based o…

The LBV Phase of the Planetary Nebula LMC-N66

Peña, M.

Recent observations of the [WN] central star of the planetary nebula LMC-N66, combined with previous data show that the star has been slowly fading, after its violent LBV-type outburst occurred in 1994. The present stellar brightness ( m[V] ~ 18.1 mag) and the probable mass loss rate are similar to the values observed in 1990. Nebular data from lo…

An Ionized Microjet from the Orion Nebula Proplyd LV 2

Henney, W. J.; Meaburn, J.; Garrington, S. T.

We present results of multi-wavelength observations of the Orion nebula proplyd LV 2 (M42 167-317), concentrating on our analysis of the microjet that emerges from the proplyd's ionization front. The microjet is one-sided at its base but faint, symmetrical jet filaments are seen on both sides at arcsecond scales. The physical characteristics of th…

The Structure of the Planetary Nebula IC 2149: A Jet or an Edge-On Ring?

López, J. A.; Torrelles, J. M.; Miranda, L. F. +4 more

A set of optical and radio observations of the peculiar planetary nebula (PN) IC 2149 is presented. A bow-shock-like feature towards the NE edge is first detected with the VLA-A, and is also confirmed with HST archive images. Optical spectroscopy leads to apparently contradictory results, leaving this object as a unique case among the planetary ne…