Abnormal CNO abundances in magnetic cataclysmic variables

2002 ◽  
Author(s):  
M. Mouchet
Keyword(s):  
Cataclysmic Variables ◽  
Magnetic Cataclysmic Variables ◽  
Cno Abundances

scholarly journals Far-UV FUSE Spectra of Peculiar Magnetic Cataclysmic Variables

2004 ◽  
Vol 190 ◽  
pp. 142-148
Author(s):  
Martine Mouchet ◽  
Jean-Marc Bonnet-Bidaud ◽  
Evelyne Roueff ◽  
Meil Abada-Simon ◽  
Klaus Beuermann ◽  
...  
Keyword(s):  
Cataclysmic Variables ◽  
Uv Spectra ◽  
Radial Velocities ◽  
Emission Region ◽  
Magnetic Cataclysmic Variables ◽  
Cno Abundances ◽  
Uv Range

AbstractWe present far-UV spectra of the three magnetic cataclysmic variables (MCVs) BY Cam, V1309 Ori and AE Aqr obtained with the FUSE satellite. These MCVs have revealed strongly unusual NV and CIV UV resonance lines. The FUSE spectra exhibit broad OVI lines as well as a strong NIII line at 991Å, while the CIII 1175Å line is nearly absent, supporting non-solar CNO abundances of the accreting matter in these sources. The spectrum of BY Cam shows molecular H2 lines which might be of circumstellar nature. The flaring activity of AE Aqr is also observed in the far-UV range. The radial velocities of the broad OVI components in AE Aqr are orbitally modulated and would indicate an emission region close to the magnetosphere.

scholarly journals Extreme Ultraviolet Spectroscopy of Magnetic Cataclysmic Variables

1996 ◽  
Vol 152 ◽  
pp. 309-316
Author(s):  
Frits Paerels ◽  
Min Young Hur ◽  
Christopher W. Mauche
Keyword(s):  
High Resolution ◽  
White Dwarf ◽  
Extreme Ultraviolet ◽  
Cataclysmic Variables ◽  
Ultraviolet Spectroscopy ◽  
Temperature Structure ◽  
Polar Cap ◽  
Ultraviolet Emission ◽  
X Ray ◽  
Magnetic Cataclysmic Variables

A longstanding problem in the interpretation of the X-ray and extreme ultraviolet emission from strongly magnetic cataclysmic variables can be addressed definitively with high resolution EUV spectroscopy. A detailed photospheric spectrum of the accretion-heated polar cap of the white dwarf is sensitive in principle to the temperature structure of the atmosphere. This may allow us to determine where and how the bulk of the accretion energy is thermalized. The EUVE data on AM Herculis and EF Eridani are presented and discussed in this context.

scholarly journals Accretion Flows in Magnetic Cataclysmic Variables

2004 ◽  
Vol 194 ◽  
pp. 138-139
Author(s):  
A. J. Norton ◽  
R. V. Somerscales ◽  
T. L. Parker ◽  
G. A. Wynn ◽  
R. G. West
Keyword(s):  
Cataclysmic Variables ◽  
Outer Edge ◽  
Roche Lobe ◽  
Accretion Flows ◽  
Magnetic Cataclysmic Variables

AbstractWe present the results of simulations that explore the variety of accretion flows possible in magnetic cataclysmic variables (mCVs). Our simulations evolve to equilibrium periods spanning 0.01 < Рspin/Рorb < 0.6 and the resulting flows vary from disc-fed systems at Рspin/Рorb ~ 0.01 - 0.1, to stream fed systems at Рspin/Рorb ~ 0.1 - 0.5 and systems fed from a ring at the outer edge of the white dwarf's Roche lobe at Рspin/Рorb ~ 0.6.

scholarly journals The Characteristics of Magnetic CVs in the Period Gap

2004 ◽  
Vol 190 ◽  
pp. 15-21 ◽  
Author(s):  
Gaghik Tovmassian ◽  
Sergey Zharikov ◽  
Ronald Mennickent ◽  
Jochen Greiner
Keyword(s):  
Mass Transfer ◽  
Orbital Period ◽  
Accretion Rate ◽  
Cataclysmic Variables ◽  
Magnetic Systems ◽  
Transfer Rates ◽  
Significant Difference ◽  
Magnetic Cataclysmic Variables

AbstractWe have observed several magnetic cataclysmic variables located in the range between 2 and 3 hours, known as the period gap. This work was prompted by the recent discovery of RXJ1554.2+2721. It has 2.54 hours orbital period and shows almost pure cyclotron continuum in a low luminosity state, similar to HS1023+3900, HS0922+1333 and RBS206. These are low accretion rate polars (LARPs) known to have mass transfer rates of order of a few 10-13M⊙/year. The aim of the study was to find out, if magnetic systems filling the period gap are in any way different from their counterparts outside that range of periods. The only significant difference we encounter is a much higher number of asynchronous magnetic systems towards longer periods than below the gap.

scholarly journals On the Classification of Magnetic Cataclysmic Variables

2004 ◽  
Vol 194 ◽  
pp. 180-181
Author(s):  
Paul A. Mason
Keyword(s):  
Classification Scheme ◽  
Cataclysmic Variables ◽  
Intermediate Polars ◽  
Orbital Periods ◽  
Magnetic Cataclysmic Variables

AbstractThe classification scheme for Magnetic Cataclysmic Variables (MCVs) is addressed. When only ten or twenty MCVs had been discovered their classification was simple and based on direct observational properties. Now that the number of MCVs exceeds one hundred, the method of classification needs updating. One important consideration is the possibility that binaries might physically change their classification. For example will intermediate polars become polars as they evolve to shorter orbital periods? Or does a polar become an intermediate polar when synchronism is broken due to a nova?

X-ray emission from non-magnetic cataclysmic variables

Nature ◽  
1984 ◽  
Vol 308 (5959) ◽  
pp. 519-521 ◽  
Author(s):  
A. R. King ◽  
G. Shaviv
Keyword(s):  
Cataclysmic Variables ◽  
X Ray ◽  
Magnetic Cataclysmic Variables
Sign in / Sign up

Export Citation Format

Share Document