Fast, low-ionization emission regions of the planetary nebula M2-42

A. Danehkar,
Department of Physics and Astronomy, Macquarie University, Sydney, NSW 2109, Australia
Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA

Q. A. Parker,
Australian Astronomical Observatory, PO Box 915, North Ryde, NSW 1670, Australia
Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong, China

W. Steffen
Instituto de Astronomía, Universidad Nacional Autónoma de México, C.P.22860, Ensenada, Mexico

Date: Received 2015 March 18; accepted 2015 December 18; published 2016 January 28


Spatially-resolved observations of the planetary nebula M2-42 (PNG008.2$ -$04.8) obtained with the Wide Field Spectrograph on the Australian National University 2.3 m telescope have revealed the remarkable features of bipolar collimated jets emerging from its main structure. Velocity-resolved channel maps derived from the [NII] $ \lambda $6584 emission line disentangle different morphological components of the nebula. This information is used to develop a three-dimensional morpho-kinematic model, which consists of an equatorial dense torus and a pair of asymmetric bipolar outflows. The expansion velocity of about 20 kms$ ^{-1}$ is measured from the spectrum integrated over the main shell. However, the deprojected velocities of the jets are found to be in the range of $ 80$-160 kms$ ^{-1}$ with respect to the nebular center. It is found that the mean density of the collimated outflows, $ 595 \pm 125$cm$ ^{-3}$, is five times lower than that of the main shell, $ 3150$cm$ ^{-3}$, whereas their singly-ionized nitrogen and sulfur abundances are about three times higher than those determined from the dense shell. The results indicate that the features of the collimated jets are typical of fast, low-ionization emission regions (FLIERs).
Keywords: ISM: jets and outflows - planetary nebulae: individual (M2-42)
Journal Reference: A. Danehkar, Q. A. Parker, and W. Steffen. The Astronomical Journal, 151:38, 2016. doi:10.3847/0004-6256/151/2/38

Ashkbiz Danehkar