Intensity Distribution in the Fine Structure of the Balmer Lines

Nature ◽  
1927 ◽  
Vol 119 (2993) ◽  
pp. 393-393 ◽  
Author(s):  
G. E. HARRISON
Keyword(s):  
Fine Structure ◽  
Intensity Distribution ◽  
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

scholarly journals Intensity measurements in a fine structure multiplet of As II

1934 ◽  
Vol 146 (859) ◽  
pp. 818-824 ◽  
Keyword(s):  
Fine Structure ◽  
Intensity Distribution ◽  
Nuclear Spin ◽  
Inherent Difficulty ◽  
Intensity Measurements ◽  
Fine Structures ◽  
Intensity Ratios ◽  
Instrumental Intensity ◽  
Spin Multiplet

The present work was undertaken with the object of testing the fine structure intensity formulæ deduced by Hill. Up to the present very few intensity measurements have been made on the fine structures arising from nuclear spin. The principal difficulty in such measurements arises from the smallness of the structures which are usually incompletely resolved by the interferometers employed. The use of the interferometer in any event necessitates careful corrections for the instrumental intensity distribution. Schüler and Keyston have made photometric determinations of the intensity ratios in the fine structures of two Cdl lines and have verified the intensity rules for these lines. An inherent difficulty in the examination with a FabryPerot interferometer of Cdl structures lies in the presence of an intense evei isotope line within the pattern due to the nuclear spin of the odd isotopes The even isotope component contributes 77% of the intensity of the line and the remaining 23% is distributed amongst the members of the nuclear spin multiplet. The authors do not describe their method of coping with this difficulty which, judging from the experience of the present writers, must have been serious.

Fine structure and spectral broadening of Balmer lines in laser-produced plasmas

1979 ◽  
Vol 20 (6) ◽  
pp. 2574-2581 ◽  
Author(s):  
P. Nicolosi ◽  
G. Tondello ◽  
E. Jannitti
Keyword(s):  
Fine Structure ◽  
Spectral Broadening ◽  
Balmer Lines

Experimental Study of the Stark Broadened Helium Ion Lines Hell 121.5, 164.0 and 468.6 nm

1984 ◽  
Vol 39 (11) ◽  
pp. 1041-1048 ◽  
Author(s):  
A. Piel ◽  
J. Slupek
Keyword(s):  
Experimental Study ◽  
Fine Structure ◽  
High Purity ◽  
Laser Interferometer ◽  
Plasma Parameters ◽  
Line Shapes ◽  
Helium Ion ◽  
Balmer Lines ◽  
Theoretical Line ◽  
Coupled Cavity

Using a pulsed linear discharge of high purity, Stark broadened profiles of the first two Balmer lines and the Paschen-α line of HeII have been investigated. The electron density (Ne = 5.5 · 1022 m-3) was measured with a coupled cavity He-Ne laser interferometer. The intensity ratio of the HeII 468.6 nm and the HeI 471.3 nm line was employed to determine the electron temperature (Te = 3.8 eV). At these plasma parameters the measured ion lines are unaffected by self absorption. This enables direct comparison with existing theories. Discrepancies between experimental and theoretical line shapes are critically discussed. Fine structure effects, usually neglected in theories, turn out to be important for the Balmer-α line.

Doublet Separation and Fine Structure of the Balmer Lines of Hydrogen

1927 ◽  
Vol 30 (3) ◽  
pp. 266-283 ◽  
Author(s):  
Norton A. Kent ◽  
Lucien B. Taylor ◽  
Hazel Pearson
Keyword(s):  
Fine Structure ◽  
Balmer Lines
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