The magnetic field and emission-line spectrum of the remarkable white dwarf GD 356

This study aims to know what will happen when the emission line spectrum emitted by gas tube of the hydrogen atom electron at certain wavelength passed in an external magnetic field. This study was analyzed by non quantitaive comparing between without field and with an external magnetic field. Based on the results of research done obtained a result that the emission spectrum of hydrogen gas passed in an external magnetic field changed the intensity of spectrum. The larger intensity of the magnetic field radiated, that shows where the larger magnetic field used the larger distance split of spectral line .

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The Ionization of Novae Ejecta

International Astronomical Union Colloquium ◽

10.1017/s0252921100068664 ◽

1990 ◽

Vol 122 ◽

pp. 215-227

Author(s):

R.E. Williams

Keyword(s):

Emission Line ◽

White Dwarf ◽

Line Spectrum ◽

Ionized Gas ◽

Grain Formation ◽

Emission Line Spectrum ◽

Pass Through

AbstractNovae ejecta pass through four distinct phases of evolution of the emission-line spectrum, caused by different ionization characteristics of the shell. These include a neutral (I), an auroral (II), a coronal (III), and a nebular (IV) phase. Photoionization from the contracting photosphere of the hot white dwarf is the source of the ionization, including the highly ionized coronal phase. Changing emission line ratios in certain novae that develop dust are caused by condensation of grains from the gas, and can be used to determine the composition of the dust. In V1370 Aql, substantial silicate grain formation appears to have taken place, probably within the ionized gas.

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Photometry of AM Her Stars – Line and Continuum Emission

International Astronomical Union Colloquium ◽

10.1017/s0252921100076132 ◽

1979 ◽

Vol 53 ◽

pp. 324-328

Author(s):

Paula Szkody

Keyword(s):

Emission Line ◽

White Dwarf ◽

Main Sequence ◽

Close Binary ◽

Line Spectrum ◽

Continuum Emission ◽

Late Type ◽

Emission Line Spectrum ◽

Orbital Periods

The 4 known AM Her stars or polars (AM Her, ANUMa, W Pup, and 2A0311-227) are characterized by large circular polarizations of 10-35%, (Tapia 1977a, b, Krzeminski and Serkowski 1977), an emission line spectrum with strong H and He lines (Crampton and Cowley 1977, Greenstein et al. 1977), complex photometric variations (Szkody 1978, Priedhorsky and Krzeminski 1978, Warner & Nather 1972), long term high and low states and short orbital periods (80-180 min.). Models of these systems envision a close binary containing a magnetic white dwarf primary (B ~ 108G) and late type main sequence secondary transferring material into an accretion funnel over one or both poles of the white dwarf (Stockman et al. 1977, Lamb & Masters 1979, Liebert et al. 1978).

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The unusual emission line spectrum of I Zw 1

Proceedings of the International Astronomical Union ◽

10.1017/s1743921304002248 ◽

2004 ◽

Vol 2004 (IAUS222) ◽

pp. 271-274

Author(s):

Monique Joly ◽

M.-P. Véron-Cetty ◽

P. Véron

Keyword(s):

Emission Line ◽

Line Spectrum ◽

Emission Line Spectrum

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The May 1985 Superoutburst of OY Carinae: II. Phase-Resolved IUE Spectroscopy and Exosat Observations

International Astronomical Union Colloquium ◽

10.1017/s025292110010510x ◽

1987 ◽

Vol 93 ◽

pp. 371-376 ◽

Cited By ~ 2

Author(s):

B.J.M. Hassall ◽

T. Naylor ◽

G.T. Bath ◽

P.A. Charles ◽

G. Sonneborn ◽

...

Keyword(s):

Emission Line ◽

Line Spectrum ◽

X Ray ◽

Dwarf Nova ◽

Uv Emission ◽

Emission Line Spectrum ◽

Coronal Region

AbstractWe present ultraviolet and X-ray observations of the eclipsing SU UMa dwarf nova OY Car early in the decline from a superoutburst. From the UV emission line spectrum and lack of X-ray eclipse, we deduce the presence of an extended coronal region.

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Models for the Emission-Line Spectra of the Low-Excitation Herbig-Haro Objects

Symposium - International Astronomical Union ◽

10.1017/s0074180900095784 ◽

1987 ◽

Vol 115 ◽

pp. 346-347

Author(s):

Michael A. Dopita ◽

Saul Caganoff ◽

Richard D. Schwartz ◽

Martin Cohen

Keyword(s):

Emission Line ◽

Theoretical Description ◽

Line Spectrum ◽

High Excitation ◽

Two Photon ◽

Shock Models ◽

Uv Excess ◽

Hh Objects ◽

Emission Line Spectrum

The class of Low-Excitation Herbig-Haro Objects are characterised by [SII] and [OI] lines which are comparable in strength to H-Alpha, by [NI] lines that are comparable to H-Beta, relatively weak [NII] and [OII] lines, little or no [OIII] emission and a very strong blue-UV “excess”. This blue and UV continuum in low-excitation HH Objects was noted as a problem by Brugel, Böhm and Mannery (1981), Ortalani and D'Odorico (1980) and Böhm, Böhm-Vitense and Brugel (1981). The first suggestion that it results from collisionally enhanced Hydrogen two-photon (2q) continuum was by Dopita (1981). The subsequent observations of Dopita, Binette and Schwartz (1982) proved that this was indeed the case. However, although very close correlations between this enhancement and the emission-line spectrum were found, a fair theoretical description could only be obtained for very youthful shock models with ages of order 30 years. However, there seems to be no reason why low excitation HH shocks should be much younger than the high excitation shocks.

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The Chandrasekhar Mass of A Gravitating Electron Crystal

International Astronomical Union Colloquium ◽

10.1017/s0252921100026610 ◽

1994 ◽

Vol 147 ◽

pp. 565-570

Author(s):

D. Engelhardt ◽

I. Bues

Keyword(s):

Magnetic Field ◽

Density Matrix ◽

White Dwarf ◽

Matrix Formalism ◽

Plasma Zone ◽

Isothermal Model ◽

Fermi Function ◽

Density Matrix Formalism ◽

The Magnetic Field ◽

Electron Crystal

AbstractThe internal structure of a white dwarf may be changed by a strong magnetic field. A local model of the electrons is constructed within a thermal density matrix formalism, essentially a Heisenberg magnetism model. This results in a matrix Fermi function which is used to construct an isothermal model of the electron crystal. The central density of the crystal is 108kg/m3 independent of the magnetic field within the plasma and therefore lower than the relativistic density, whereas this density is constant until the Fermi momentum x f = 0.3 * me * c. Chandrasekhar masses up to 1.44 * 1.4M0 are possible for polarizations of the plasma zone lower than 0.5, if the temperature is close to the Curie point, whereas the crystal itself destabilizes the white dwarf dependent on temperature.

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Nova GK Persei – A Miniature Supernova Remnant?

International Astronomical Union Colloquium ◽

10.1017/s025292110010209x ◽

1988 ◽

Vol 101 ◽

pp. 47-50

Author(s):

E.R. Seaquist ◽

D.A. Frail ◽

M.F. Bode ◽

J.A. Roberts ◽

D.C.B. Whittet ◽

...

Keyword(s):

Magnetic Field ◽

Synchrotron Radiation ◽

Strong Evidence ◽

White Dwarf ◽

Planetary Nebula ◽

Supernova Remnants ◽

Supernova Remnant ◽

Optical Images ◽

Ambient Gas ◽

The Magnetic Field

AbstractWe present radio and optical images of the shell-like remnant of the 1901 outburst of Nova GK Persei. The behaviour of this object is remarkably similar to supernova remnants. The synchrotron radiation-emitting shell is polarized with the magnetic field oriented radially, as in young SNR’s. This similarity plus extensive data we have acquired on the expansion and the interstellar environment of GK Per indicate that the nova shell is colliding with ambient gas whose density is substantially higher than the ISM.Furthermore, there is strong evidence that the ambient gas is circumstellar rather than interstellar, and that this material is the shell of an ancient planetary nebula associated with the white dwarf companion of GK Per.

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