scholarly journals On the internal kinematics of PNe

2011 ◽  
Vol 7 (S283) ◽  
pp. 400-401
Author(s):  
Ralf Jacob ◽  
Detlef Schönberner ◽  
Holger Lehmann ◽  
Alena Zwanzig ◽  
Christer Sandin ◽  
...  
Keyword(s):  
High Resolution ◽  
Surface Chemistry ◽  
Post Shock ◽  
Expanding Shells ◽  
Central Stars

AbstractOur sample of round/elliptical double-shell PNe around central stars (CSs) with H-rich surface chemistry covers all evolutionary phases across the HRD. By means of high-resolution and high-S/N spectra we determine bulk matter velocities of the inner wind-driven rims and the maximum (= post-shock) gas velocities of the surrounding thermally expanding shells. Studying the details of the internal kinematics allows a look at processes of PN formation and at PN expansion history helping, for instance, to determine expansion distances.

scholarly journals A High Resolution Far-UV Spectral Atlas of CSPNs and Hot White Dwarfs

1993 ◽  
Vol 155 ◽  
pp. 91-91
Author(s):  
R.W. Tweedy
Keyword(s):  
High Resolution ◽  
White Dwarfs ◽  
Planetary Nebulae ◽  
Central Star ◽  
Evolutionary Sequence ◽  
Spectroscopic Analyses ◽  
Spectroscopic Information ◽  
The University ◽  
Phd Thesis ◽  
Central Stars

A high-resolution IUE spectral atlas of central stars of planetary nebulae and hot white dwarfs has been produced (part of Tweedy, 1991, PhD thesis from the University of Leicester, UK), and examples from it are shown here. It has been sorted into an approximate evolutionary sequence, based on published spectroscopic analyses, from the cool 28,000K young central star He 2–138, through the hot objects like NGC 7293 and NGC 246 at 90,000K and 130,000K respectively, down to 40,000K DA white dwarfs like GD 2, which is the chosen cutoff for this selection. Copies of a revised version of this atlas, which will include more recent spectroscopic information and also white dwarfs down to 35,000K – to include the Si III object GD 394 – will be sent to anyone who requests one.

scholarly journals Post-AGB binaries as tracers of stellar evolution.

2016 ◽  
Vol 12 (S323) ◽  
pp. 231-234 ◽  
Author(s):  
Hans Van Winckel
Keyword(s):  
Time Series ◽  
High Resolution ◽  
Stellar Evolution ◽  
Accretion Disc ◽  
Monitoring Programme ◽  
Use Of Time ◽  
Central Stars

AbstractIn this contribution the focus is on post-AGB binaries. It is now well established that these are often surrounded by stable long-lived circumbinary discs of gas and dust. Here we introduce our monitoring programme with our high-resolution spectrograph HERMES mounted on the 1.2m Mercator telescope. We illustrate the use of time-series high-resolution spectra and show that jets observed in many systems are launched at the location of the companion. The jet is likely originating from a circum-companion accretion disc. The link of these systems to some PNe relies on the detection of similar orbits and hence wide spectroscopic orbits among central stars of PNe. The conclusion is that Keplerian discs as well as circum-companion discs are fundamental to understanding the properties and evolution of these interacting evolved binaries.

The effect of local lithium surface chemistry and topography on solid electrolyte interphase composition and dendrite nucleation

2019 ◽  
Vol 7 (24) ◽  
pp. 14882-14894 ◽  
Author(s):  
Melissa L. Meyerson ◽  
Jonathan K. Sheavly ◽  
Andrei Dolocan ◽  
Monroe P. Griffin ◽  
Anish H. Pandit ◽  
...  
Keyword(s):  
High Resolution ◽  
Surface Chemistry ◽  
Solid Electrolyte ◽  
Solid Electrolyte Interphase ◽  
Dendrite Growth ◽  
Lithium Deposition ◽  
High Resolution Analysis ◽  
Resolution Analysis

High resolution analysis shows localized organic-rich impurities in the native Li surface that promote preferential lithium deposition, leading to dendrite growth.

scholarly journals Planetary Nebulae with binary nuclei

1997 ◽  
Vol 180 ◽  
pp. 74-84 ◽  
Author(s):  
Mario Livio
Keyword(s):  
High Resolution ◽  
Crucial Role ◽  
Binary Systems ◽  
Planetary Nebulae ◽  
Specific Mechanism ◽  
Essential Information ◽  
Common Envelope ◽  
High Resolution Images ◽  
The Common ◽  
Central Stars

High resolution images of planetary nebulae have revealed a variety of non-spherical morphologies. In addition, some planetary nebulae were found to produce highly collimated jets. It is argued that binary central stars may play a crucial role in the production of all of these morphologies. In particular, a specific mechanism is identified for the generation of “point-symmetric” nebulae. It is shown that the study of binary nuclei of planetary nebulae can provide essential information for the understanding of the common envelope phase in the evolution of binary systems.

Surface Chemistry of Ultrathin Films of Histidine on Gold As Probed by High-Resolution Synchrotron Photoemission

2005 ◽  
Vol 109 (2) ◽  
pp. 884-891 ◽  
Author(s):  
Yan Zubavichus ◽  
Michael Zharnikov ◽  
Yongjie Yang ◽  
Oliver Fuchs ◽  
Clemens Heske ◽  
...  
Keyword(s):  
High Resolution ◽  
Surface Chemistry ◽  
Ultrathin Films

scholarly journals The Metal-Line Spectra of Central Stars of Planetary Nebulae

1989 ◽  
Vol 131 ◽  
pp. 317-317
Author(s):  
M. Roth ◽  
A. Herrero ◽  
R. H. Mendez ◽  
R. P. Kudritzki ◽  
K. Butler ◽  
...  
Keyword(s):  
High Resolution ◽  
Planetary Nebulae ◽  
Line Formation ◽  
Echelle Spectrograph ◽  
Metal Line ◽  
Metal Abundances ◽  
Central Stars

We present spectral descriptions based on high-resolution spectrograms of central stars of planetary nebulae, obtained with the ESO 3,6-m telescope + CASPEC (Cassegrain Echelle Spectrograph). We make preliminary determinations of stellar photospheric metal abundances, using non-LTE model atmospheres and non-LTE line formation calculations.

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