High resolution optical spectra of 120 white dwarfs

2008 ◽  
pp. 524-524 ◽  
Author(s):  
David Tytler ◽  
Eric Rubenstein
Keyword(s):  
High Resolution ◽  
White Dwarfs ◽  
Optical Spectra

scholarly journals High Resolution Optical Spectra of 120 White Dwarfs

1989 ◽  
Vol 114 ◽  
pp. 524-524 ◽  
Author(s):  
David Tytler ◽  
Eric Rubenstein
Keyword(s):  
High Resolution ◽  
White Dwarfs ◽  
Binary Systems ◽  
High Amplitude ◽  
Optical Spectra ◽  
Absorption Lines ◽  
Type I ◽  
High Quality ◽  
Velocity Variations

AbstractHigh quality optical spectra of 120 white dwarfs have been obtained to search for double degenerate systems, some of which might become type I supernovae. No systems with high amplitude velocity variations have been found. However several exceptionally cool DA white dwarfs have been found to show weak Helium absorption lines, and four stars have split H-alpha line cores indicative of binary systems.

scholarly journals 5.18. Molecular gas in the poststarburst galaxy NGC7331

1998 ◽  
Vol 184 ◽  
pp. 247-248
Author(s):  
T. Tosaki ◽  
Y. Shioya
Keyword(s):  
High Resolution ◽  
Spiral Galaxy ◽  
Stellar Populations ◽  
Optical Spectra ◽  
Molecular Gas ◽  
Early Type ◽  
Origin And Evolution ◽  
Co Observations

To understand the origin and evolution of starburst activity, we must study the full evolution of starburst; i.e., pre-, on-going, and post-starburst phases. It seems reasonable to suppose the numerous A-type stars indicate past starburst and they show strong Balmer absorption. NGC7331, nearby early-type spiral galaxy, is one of the poststarburst galaxies which show strong Balmer absorption. The optical spectra of NGC7331 were dominated by component of intermediate-age (5 × 109 years) stellar populations (Ohyama & Taniguchi 1996). We present the result of the high resolution CO observations of NGC7331 using Nobeyama Milimeter Array.

scholarly journals High Velocity Outflows in IRAS 17423-1755

1993 ◽  
Vol 155 ◽  
pp. 348-348
Author(s):  
A. Riera ◽  
P. García-Lario ◽  
A. Manchado ◽  
S.R. Pottasch
Keyword(s):  
High Resolution ◽  
High Velocity ◽  
Planetary Nebula ◽  
Optical Spectra ◽  
Bipolar Structure ◽  
La Palma ◽  
Pn Stage ◽  
Observational Program

IRAS 17423-1755 is a new transition object between the post-AGB phase and the planetary nebula (PN) stage included in an observational program of IRAS sources with infrared colours similar to those of PNe. We have taken B, V, R, I, Z, Hα and [OIII] CCD images at the 1m JKT (Roque de los Muchachos, La Palma), where a clearly marked bipolar structure with a total extension of about 10″ can be seen, and long slit (low and high resolution) optical spectra at the 4.2m WHT, 2.5m INT (RM, La Palma) and ESO 1.5m (La Silla) telescopes.

scholarly journals Abundances of disk and bulge giants from high-resolution optical spectra

2017 ◽  
Vol 600 ◽  
pp. C2 ◽  
Author(s):  
H. Jönsson ◽  
N. Ryde ◽  
M. Schultheis ◽  
M. Zoccali
Keyword(s):  
High Resolution ◽  
Optical Spectra

scholarly journals The High Resolution Spectrum of the Pulsating, Pre-White Dwarf Star PG 1159-035 (GW VIR)

1989 ◽  
Vol 114 ◽  
pp. 384-387
Author(s):  
James Liebert ◽  
F. Wesemael ◽  
D. Husfeld ◽  
R. Wehrse ◽  
S. G. Starrfield ◽  
...  
Keyword(s):  
High Resolution ◽  
Effective Temperature ◽  
White Dwarf ◽  
White Dwarfs ◽  
High Resolution Spectrum ◽  
Dwarf Star ◽  
Dwarf Stars ◽  
New Class ◽  
White Dwarf Stars ◽  
Nonradial Pulsation

First reported at the IAU Colloquium No. 53 on White Dwarfs (McGraw et al. 1979), PG 1159-035 (GW Vir) is the prototype of a new class of very hot, pulsating, pre-white dwarf stars. It shows complicated, nonradial pulsation modes which have been studied exhaustively, both observationally and theoretically. The effective temperature has been crudely estimated as 100,000 K with log g ~ 7 (Wesemael, Green and Liebert 1985, hereafter WGL).

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 Analysis of the hydrogen-rich magnetic White Dwarfs in the SDSS

2008 ◽  
Vol 4 (S259) ◽  
pp. 379-380
Author(s):  
Baybars Külebi ◽  
Stefan Jordan ◽  
Fabian Euchner ◽  
Heiko Hirsch
Keyword(s):  
Magnetic Field ◽  
Least Squares ◽  
White Dwarfs ◽  
Optical Spectra ◽  
Digital Survey ◽  
Least Squares Minimization ◽  
Minimization Scheme ◽  
Field Strengths

AbstractWe have calculated optical spectra of hydrogen-rich (DA) white dwarfs with magnetic field strengths between 1 MG and 1000 MG for temperatures between 7000 K and 50000 K. Through a least-squares minimization scheme, we have analyzed the spectra of 114 magnetic DAs from the Sloan Digital Survey (SDSS; 95 previously published plus 14 newly discovered within SDSS).

High-resolution optical spectra of laser cooled ions

1980 ◽  
Vol 22 (4) ◽  
pp. 365-368 ◽  
Author(s):  
R. E. Drullinger ◽  
D. J. Wineland ◽  
J. C. Bergquist
Keyword(s):  
High Resolution ◽  
Optical Spectra
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