A Preferred Orientation Angle for Bipolar Planetary Nebulae

We present preliminary results from measuring Galactic orientation angles of 800 elliptical and bipolar Planetary Nebulae (PNe) in the Hong Kong/Australian Astronomical Observatory/Strasbourg Observatory H-alpha Planetary Nebula (HASH) research platform and database (Parker et al. [1], [2]). For elliptical PNe the distribution of orientation angles is found to be essentially uniform. However, for bipolar PNe there is statistically significant evidence for preferred orientation angles (as tentatively reported before with smaller samples) across the whole Galaxy.

[1]  Janet E. Drew,et al.  Initial data release from the INT Photometric Hα Survey of the Northern Galactic Plane (IPHAS) , 2007, 0712.0384.

[2]  N. Hambly,et al.  The AAO/UKST SuperCOSMOS Hα survey , 2005, astro-ph/0506599.

[3]  H. Monteiro,et al.  On the alignment of PNe and local magnetic field at the Galactic centre : magnetohydrodynamical numerical simulations , 2013, 1312.2910.

[4]  R. Izzard,et al.  Dawes Review 6: The Impact of Companions on Stellar Evolution , 2016, Publications of the Astronomical Society of Australia.

[5]  J. Köppen,et al.  The Macquarie/AAO/Strasbourg Hα Planetary Nebula Catalogue: MASH , 2006 .

[6]  A. Zijlstra,et al.  Alignment of the angular momentum vectors of planetary nebulae in the Galactic Bulge , 2013, 1307.5711.

[7]  Q. Parker,et al.  Planetary Nebulae: Observational Properties, Mimics and Diagnostics , 2010, Publications of the Astronomical Society of Australia.

[8]  Quentin A. Parker,et al.  Exploiting the HASH Planetary Nebula Research Platform , 2016, Proceedings of the International Astronomical Union.

[9]  O. Marco.  The Origin and Shaping of Planetary Nebulae: Putting the Binary Hypothesis to the Test , 2009, 0902.1137.

[10]  Hugo E. Schwarz,et al.  Morphological populations of planetary nebulae: which progenitors? 1. Comparative properties of bipolar nebulae , 1994 .

[11]  Ivan Bojicic,et al.  HASH: the Hong Kong/AAO/Strasbourg Hα planetary nebula database , 2016, 1603.07042.

[12]  A. Zijlstra,et al.  A high-mass planetary nebula in a Galactic open cluster , 2019, Nature Astronomy.

[13]  W. Weidmann,et al.  The Spatial Orientation of Planetary Nebulae within the Milky Way , 2005, astro-ph/0505092.

[14]  Q. Parker,et al.  Orientation of galactic bulge planetary nebulae toward the Galactic center , 2014, Proceedings of the International Astronomical Union.

[15]  S. R. Jammalamadaka,et al.  Topics in Circular Statistics , 2001 .

[16]  Nicholas I. Fisher,et al.  Statistical Analysis of Circular Data , 1993 .

[17]  D. Wilkie,et al.  Rayleigh Test for Randomness of Circular Data , 1983 .

[18]  J. P. Phillips.  The spatial orientations of bipolar nebulae , 1997 .

[19]  R. Corradi,et al.  Orientation of planetary nebulae within the Galaxy , 1998 .