scholarly journals Expansion Velocities of Southern Planetary Nebulae K.C. Sahu

1989 ◽  
Vol 131 ◽  
pp. 196-196
Author(s):  
K. C. Sahu ◽  
S. R. Pottasch
Keyword(s):  
Statistical Analysis ◽  
High Resolution ◽  
Physical Properties ◽  
Planetary Nebulae ◽  
Echelle Spectrograph ◽  
Distance Measurements ◽  
Preliminary Results ◽  
Kinematic Study ◽  
First Results

We have undertaken a programme of kinematic study of southern planetary nebulae by obtaining high-resolution (R ≥ 50,000) spectra, using the ESO 1.5-m telescope + the Coudé Echelle Spectrograph. As first results of this study, this paper presents previously unknown expansion velocities of 16 planetary nebulae. This result increases the total number of planetary nebulae for which the expansion velocities are now known by about 10%. Further, reliable distance measurements and other physical properties are available for most of these sources. Hence this sample significantly improves the previously available data for statistical analysis related to the dynamics and evolution of planetary nebulae. Some preliminary results based on such statistical analysis are presented. The details of the results will be published in Astron. Astrophys.

scholarly journals High-Resolution Radial Velocity and Hα Study of Proto-Planetary Nebulae

1993 ◽  
Vol 155 ◽  
pp. 354-354 ◽  
Author(s):  
B.J. Hrivnak ◽  
A.W. Woodsworth
Keyword(s):  
High Resolution ◽  
Physical Properties ◽  
Radial Velocity ◽  
Planetary Nebulae ◽  
Agb Stars ◽  
Binary Nature ◽  
Circumstellar Shells

We are engaged in a program to monitor radial velocity variability in proto-planetary nebulae (PPN). Observations are being made with the radial velocity spectrometer at the DAO, with a precision of ±0.5 km s−1. Radial velocity variability can arise from binary motion and/or pulsation in these post-AGB stars. The demonstration of a binary nature for some of these objects can have important implications for the understanding of their physical properties, and for the shaping of their circumstellar shells.

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.

scholarly journals Tracing Outflows in High-Redshift Quasars

2009 ◽  
Vol 5 (S267) ◽  
pp. 406-406
Author(s):  
Leah E. Simon ◽  
Fred Hamann
Keyword(s):  
High Resolution ◽  
Physical Properties ◽  
Absorption Line ◽  
High Redshift ◽  
Preliminary Results

We present preliminary results from the largest-ever survey of high-resolution associated absorption line (AAL) region metallicities and physical properties in a sample of high redshift (z > 3) quasars.

scholarly journals MUSICOS 92 observations of Θ2 Tauri

1994 ◽  
Vol 162 ◽  
pp. 110-111
Author(s):  
E.J. Kennelly ◽  
G.A.H. Walker ◽  
Keyword(s):  
High Resolution ◽  
International Collaboration ◽  
High Resolution Spectroscopy ◽  
Echelle Spectrograph ◽  
Preliminary Results ◽  
The World ◽  
Astronomical Research

MUSICOS (MUlti-SIte COntinous Spectroscopy) is an international collaboration interested in areas of astronomical research requiring continuous, high-resolution spectroscopy. The MUSICOS stategy has been 1) to organize international campaigns (Catala et al 1993), 2) to build a prototype fibre-fed, high-resolution, echelle spectrograph (Baudrand & Böhm 1992), and 3) to install duplicates of the MUSICOS spectrograph on 2m class telescopes around the world. Stages 1 and 2 have been completed. Preliminary results on θ2 Tau from the second MUSICOS campaign are presented here.

scholarly journals High Resolution Spectroscopy with a Fiber-Linked Echelle-Spectrograph

1988 ◽  
Vol 132 ◽  
pp. 9-14
Author(s):  
H. Mandel
Keyword(s):  
High Resolution ◽  
Optical Design ◽  
High Resolution Spectroscopy ◽  
Echelle Spectrograph ◽  
The Real ◽  
Preliminary Results ◽  
General Terms ◽  
Observation Period

A compact fiber-linked echelle-spectrograph has been designed and constructed at the Landessternwarte Heidelberg-Königstuhl and was successfully tested during its first observation period in the end of May 1987. The optical design of the instrument is discussed in general terms and preliminary results of the first observations are presented. The reduction of several CCD frames has shown that the real properties of the spectrograph are within a few percent of the calculated ones.

scholarly journals Optical spectra of radio planetary nebulae in the small Magellanic cloud

2008 ◽  
pp. 65-70 ◽  
Author(s):  
J.L. Payne ◽  
M.D. Filipovic ◽  
E.J. Crawford ◽  
Horta de ◽  
G.L. White ◽  
...  
Keyword(s):  
South Africa ◽  
High Resolution ◽  
Planetary Nebulae ◽  
Optical Spectra ◽  
Magellanic Cloud ◽  
Radio Sources ◽  
Small Magellanic Cloud ◽  
Preliminary Results ◽  
Central Stars ◽  
Compact Array

We present preliminary results from spectral observations of four (4) candidate radio sources co-identified with known planetary nebulae (PNe) in the Small Magellanic Cloud (SMC). These were made using the Radcliffe 1.9-meter telescope in Sutherland, South Africa. These radio PNe were originally found in Australia Telescope Compact Array (ATCA) surveys of the SMC at 1.42 and 2.37 GHz, and were further confirmed by new high resolution ATCA images at 6 and 3 cm (400 /200 ). Optical PNe and radio candidates are within 200 and may represent a sub- population of selected radio bright objects. Nebular ionized masses of these objects may be 2.6 Mo or greater, supporting the existence of PNe progenitor central stars with masses up to 8 Mo.

scholarly journals Polarimetry of R Aqr and PN M2-9

2013 ◽  
Vol 9 (S302) ◽  
pp. 400-401
Author(s):  
Silvana G. Navarro ◽  
Laurence Sabin ◽  
Julio Ramírez ◽  
David Hiriart
Keyword(s):  
Magnetic Field ◽  
Physical Properties ◽  
Binary Systems ◽  
Planetary Nebulae ◽  
San Pedro ◽  
Complex Morphology ◽  
First Results ◽  
Linear Polarisation ◽  
Binary Hypothesis

AbstractThe bipolar or more complex morphology observed in planetary nebulae have been explained by two principal hypothesis: by the existence of a companion and an accreting disk or by the effects of magnetic field, (or a combination of both). Symbiotics are binary systems and some of them show morphologies similar to those observed on planetary nebulae. This fact could support the binary hypothesis for PNe. We have therefore performed polarimetric observations of symbiotic systems and some planetary nebulae in order, first to detect linear polarisation with POLIMA at the San Pedro Mártir observatory, and ultimately to prove the existence and physical properties of those disks. We present here the first results of a project dedicated to the analysis of the polarisation observed in evolved objects starting with the PN M2-9 and R Aqr.

scholarly journals Northern Binaries in the Evrena Project

2011 ◽  
Vol 7 (S282) ◽  
pp. 71-72 ◽  
Author(s):  
V. Bakış ◽  
H. Hensberge ◽  
M. Zejda ◽  
P. de Cat ◽  
F. Yılmaz ◽  
...  
Keyword(s):  
High Resolution ◽  
Close Binaries ◽  
Echelle Spectrograph ◽  
First Results

AbstractIn the framework of the EVRENA project, high-resolution spectra of northern eclipsing close binaries in stellar groups are obtained with the HERMES Echelle spectrograph at the Mercator telescope (Roque de los Muchachos Observatory). This contribution gives the first results on DV Camelopardalis.

Non-LTE model atmosphere analyses of faint PN central stars observed with Keck HIRES

1997 ◽  
Vol 180 ◽  
pp. 120-121
Author(s):  
James K. McCarthy ◽  
Roberto H. Méndez ◽  
R.-P. Kudritzki
Keyword(s):  
High Resolution ◽  
Signal To Noise Ratio ◽  
Model Atmosphere ◽  
Helium Abundance ◽  
Line Profiles ◽  
Signal To Noise ◽  
Echelle Spectrograph ◽  
First Results ◽  
Central Stars ◽  
Temperature Surface

We are engaged in using the HIRES echelle spectrograph (Vogt et al. 1994) on the 10 m Keck I Telescope to significantly increase the number of central stars of planetary nebulae (CSPN) studied spectroscopically at high resolution and signal-to-noise ratio. With Keck we are able to extend our previous work (Méndez et al. 1988, 1992; McCarthy 1988) to much fainter magnitudes. In short, comparisons of the observed HI Balmer, HeI, and He II line profiles to the Munich grid of plane-parallel non-LTE model atmosphere line profiles provide distance- and nebula-independent determinations of CSPN effective temperature, surface gravity, and helium abundance. For CSPN showing wind emission, the comparisons are made to new “unified” models (reviewed by Kudritzki et al., this meeting) which include radiation-driven winds. The first results of this on-going program are shown below.

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