The Influence of the Stark Effect on the Fine Structure of the Balmer Lines of Hydrogen

1934 ◽  
Vol 46 (12) ◽  
pp. 1069-1075 ◽  
Author(s):  
N. P. Heydenburg
Keyword(s):  
Fine Structure ◽  
Stark Effect ◽  
Balmer Lines

scholarly journals Hour-timescale profile variations in the broad Balmer lines of the Seyfert galaxy Hour-timescale profile variations in the broad Balmer lines of the Seyfert galaxy Markarian 6

2013 ◽  
Vol 9 (S304) ◽  
pp. 407-408
Author(s):  
Norayr S. Asatrian
Keyword(s):  
Fine Structure ◽  
Emission Line ◽  
Sampling Rate ◽  
Seyfert Galaxy ◽  
Special Astrophysical Observatory ◽  
Balmer Line ◽  
Line Profiles ◽  
Balmer Lines ◽  
Profile Changes ◽  
Hydrogen Emission Line

AbstractPart of results of the multi-epoch intranight optical spectroscopic monitoring of the Markarian 6 nucleus carried out at the telescopes of 6-m of the Special Astrophysical Observatory (Russia), 2.6-m of the Byurakan Astrophysical Observatory (Armenia) and 2-m of the Tautenburg Observatory (Germany) is presented.Observations were made in 1979, 1986, 1988-1991 and 2007-2009 during a total of 33 nights with an average sampling rate of 4 spectra per night. TV-scanner and long-slit spectrographs equipped with Image Tube and CCD detector arrays were used. Altogether we analyzed 110 Hβ and 58 Hα region spectra to search for intranight variability in the broad hydrogen emission line profiles. The typical spectral resolutions were 4 Å for scanner spectra, 6 Å for photographic spectra, and 5 Å and 10 Å for CCD spectra. The S/N ratio at the continuum level near the Hβ and Hα lines was in the range 15–50.The purpose of the search was to look for the characteristic variability signatures of different kinematical models of the broad emission-line region. We considered the centering and guiding errors which can result in differences between spectra.We found variations in the broad Balmer line difference profiles on time scale of hour with the level of significance of 3.6 σ to 5.0 σ. Variations take the form of narrow, small bumps located at the blue and red sides or only at the blue side of the lines. In the intermediate level of broad line flux, the Hβ and Hα profiles show fine structure. Detected profile changes occurred at the same radial velocity shifts as the details in the fine structure.The variability is at least 2 orders of magnitude more rapid than any observed for broad Balmer line profiles in AGNs that we are aware of in the literature.Discovered extremely rapid line-profile variability may be associated with reverberation effects. Two-sided profile changes may indicate the response of circularly rotating hydrogen clouds in the BLR to a light pulse from a central source. One-sided profile variations may be attributed to a response of a non-disk component: the subarcsec scale region of the jet.

The Fine Structure of the Balmer Lines

1934 ◽  
Vol 45 (4) ◽  
pp. 263-272 ◽  
Author(s):  
W. V. Houston ◽  
Y. M. Hsieh
Keyword(s):  
Fine Structure ◽  
Balmer Lines

Higher-Order Stark Effect on Magnetic Fine Structure of the Helium Atom

2001 ◽  
pp. 753-761 ◽  
Author(s):  
Aleksandr Magunov ◽  
Vitaly Ovsiannikov ◽  
Vitaly Pal’chikov ◽  
Victor Pivovarov ◽  
Gebhard von Oppen
Keyword(s):  
Fine Structure ◽  
Helium Atom ◽  
Stark Effect ◽  
Higher Order

scholarly journals The stark effect of the fine-structure of hydrogen

1928 ◽  
Vol 119 (782) ◽  
pp. 313-334 ◽  
Keyword(s):  
Fine Structure ◽  
Hydrogen Atom ◽  
Electric Field ◽  
Quantum Dynamics ◽  
Stark Effect ◽  
Energy Levels ◽  
Structure Theory ◽  
Weak Electric Field ◽  
Classical Dynamics ◽  
Balmer Series

One of the earliest successes of classical quantum dynamics in a field where ordinary methods had proved inadequate was the solution, by Schwarzschild and Epstein, of the problem of the hydrogen atom in an electric field. It was shown by them that under the influence of the electric field each of the energy levels in which the unperturbed atom can exist on Bohr’s original theory breaks up into a number of equidistant levels whose separation is proportional to the strength of the field. Consequently, each of the Balmer lines splits into a number of components with separations which are integral multiples of the smallest separation. The substitution of the dynamics of special relativity for classical dynamics in the problem of the unperturbed hydrogen atom led Sommerfeld to his well-known theory of the fine-structure of the levels; thus, in the absence of external fields, the state n = 1 ( n = 2 in the old notation) is found to consist of two levels very close together, and n = 2 of three, so that the line H α of the Balmer series, which arises from a transition between these states, has six fine-structure components, of which three, however, are found to have zero intensity. The theory of the Stark effect given by Schwarzschild and Epstein is adequate provided that the electric separation is so much larger than the fine-structure separation of the unperturbed levels that the latter may be regarded as single; but in weak fields, when this is no longer so, a supplementary investigation becomes necessary. This was carried out by Kramers, who showed, on the basis of Sommerfeld’s original fine-structure theory, that the first effect of a weak electric field is to split each fine-structure level into several, the separation being in all cases proportional to the square of the field so long as this is small. When the field is so large that the fine-structure is negligible in comparison with the electric separation, the latter becomes proportional to the first power of the field, in agreement with Schwarzschild and Epstein. The behaviour of a line arising from a transition between two quantum states will be similar; each of the fine-structure components will first be split into several, with a separation proportional to the square of the field; as the field increases the separations increase, and the components begin to perturb each other in a way which leads ultimately to the ordinary Stark effect.

Stark-effect of the higher Balmer lines.

1947 ◽  
Vol 52 ◽  
pp. 159
Author(s):  
Elsa van Dien
Keyword(s):  
Stark Effect ◽  
Balmer Lines

scholarly journals The emission of light from spark discharges

1946 ◽  
Vol 186 (1005) ◽  
pp. 241-260 ◽  
Keyword(s):  
Stark Effect ◽  
Light Emission ◽  
Voltage Drop ◽  
Light Output ◽  
Electron Multiplier ◽  
Near Ultraviolet ◽  
Limited Applicability ◽  
Balmer Lines ◽  
Spark Channel ◽  
Discharge Gap

The investigation is concerned with the transitory effects occurring in spark channels, after the discharge gap has been' bridged completely by a streamer. Observations have been made for various gases, in particular for hydrogen and argon, at pressures of the order of 1 atm. The main features studied are the light emitted from the spark channel during the period of current flow, and also the after-glow which persists after the current has fallen to a negligible value. The results indicate that the after-glow in hydrogen is probably a thermal effect only, whilst in argon it is due also, indeed largely, to other causes of which the persistence of atoms in metastable states is the most likely. Two main experimental methods were employed: ( a ) a revolving mirror camera, similar in principle to those used previously by several investigators, and ( b ) a photoelectric electron multiplier tube coupled directly to a cathode ray oscillograph. The latter method, which is new in investigations of this character, enables quantitative light emission results to be obtained, and methods of calibrating the apparatus are described in detail. The overall time constant of the circuit was sufficiently small to enable after-glows of duration as low as 1 μsec. to be clearly distinguished. The measurements show that for currents of about 100 amp., lasting for 2-4/isec., the after-glow in argon at a pressure of about 1 atm. could be detected after some 30 μsec., whereas in hydrogen, for similar conditions, the after-glow lasted for only some 3 μsec. Other gases showed after-glows of durations varying between the limits set by hydrogen and argon. In order to correlate the light output with energy dissipation in the spark channel, calorimetric measurements were made from which the mean voltage drop during the passage of current was estimated. The channel radii were measured with photographic plates sensitive to the visible and near ultraviolet light. Observations were also made of the spectra of the light emitted from the channel. The argon spectrum showed a strong continuum, and, for hydrogen, only the Balmer lines, much broadened, were seen. The density of ionization in the spark channels is deduced approximately in several ways, from the Stark effect, in hydrogen, and from a consideration of the energy balance in the channel, in both hydrogen and argon. The various calculations are in fairly close agreement and give N i ~10 17 ions per c.c. Channel temperatures, as determined on the basis of Saha’s equation, the limited applicability of which is discussed, are shown to be about 10,000- 15,000° K. The mechanism of light emission from the channel is discussed in some detail, and it is shown that either normal excitation or electron-ion recombination could be entirely responsible for the observed effects.

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