High-resolution spectroscopy of minor atmospheric constituents

1956 ◽  
Vol 236 (1205) ◽  
pp. 159-160
Keyword(s):  
Absorption Spectrum ◽  
Vibrational Frequency ◽  
Solar Spectrum ◽  
Resolving Power ◽  
High Resolution Spectroscopy ◽  
Survey Article ◽  
Royal Observatory ◽  
Infra Red ◽  
Scientific Station ◽  
The University

In a recent survey article, Goldberg (1954) gives a list of 127 molecular bands which have been observed in the absorption spectrum of the earth’s atmosphere by studying the solar spectrum between 0.3 and 24 μ . Among these, 35 bands are attributed to the following molecules: O 3 , N 2 O, CH 4 , HDO, CO. The main purpose of this contribution to the Discussion was to show several of these bands as they appear on solar spectrograms taken at the International Scientific Station, Jungfraujoch (Switzerland), in collaboration with Dr L. Neven of the Royal Observatory, Uccle (Belgium). The altitude of this station is 3580 m. It has been pointed out in earlier notes (Migeotte & Neven 1952 a, b ) that these data have been obtained, under high resolving power, by using the prism-grating infra-red spectrograph of the University of Liege (Migeotte 1945). Between 9.33 and 10.08 μ , our spectrograms show 320 lines which are mainly due to the fine structure of the 9.6 μ band of ozone (Migeotte, Neven & Vigroux 1952). Part of our data has been analyzed recently by Kaplan (1955), of the Institute for Advanced Study in Princeton (N. J.), U. S. A. A good fit for low J has been obtained with the following upper-state parameters: vibrational frequency v 3 1042.16 cm -1 ; rotational constants: A = 3.502 1 cm -1 , B = 0.440 1 cm -1 , C = 0.388 3 Cm -1 ; δ = 0.0166 34 .

scholarly journals The infra-red absorption spectrum of nitrogen tetroxide and the structure of the molecule

1933 ◽  
Vol 141 (844) ◽  
pp. 342-362 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Rock Salt ◽  
Research Work ◽  
The Other ◽  
Resolving Power ◽  
Absorption Cell ◽  
Nitrogen Tetroxide ◽  
Degree Of Dissociation ◽  
Infra Red ◽  
The Individual

The earliest observations on the infra-red absorption spectrum of nitrogen peroxide were made by Warburg and Leithauser, who found that at ordinary temperatures the mixture of the tetroxide and dioxide had strong absorption maxima at 3•4 μ, 5•7μ, and 6•1μ. By varying the temperature, and so the degree of dissociation of tetroxide molecules into dioxide molecules, they were able to attribute the absorption band at 5•7μ, to the nitrogen tetroxide molecule, and show that the other two bands were due to the molecule of nitrogen dioxide. A later investigation by Eva von Bahr confirmed these observations and disclosed another band due to the dioxide at 7•3μ. None of these investigators examined the region beyond 8 μ, and all the work was done using low dispersion. Recently Strong and Woo have examined the spectrum between 23 μ, and 150 μ, and find two main regions of absorption, one near 26 μ and 150 μ and the other around 80 μ. Experimental. The spectrometer used in the first survey of the spectrum was a prism instru­ment having a 60° rock salt prism in the Wadsworth mounting. Subsequently several of the bands were examined on grating instruments of high resolving power. The absorption cell used in the preliminary work was of brass, 20 cm. in length, and with rock salt windows. This cell was lagged with asbestos and could be heated electrically until the temperature of the gas which it contained was as high as 160° C. The absorption cell used in the examination of the individual bands was of glass, 10 cm. long, and with mica windows. For work in the region beyond 7 μ. the mica windows were replaced by ones of rock salt. The nitrogen peroxide was taken from a very pure sample specially prepared for research work. It was kept in a sealed pyrex tube as a liquid (under its own pressure) and the gas was transferred to the cells as required, drying tubes containing phosphorus pentoxide being used to avoid con­tamination from water vapour in the atmosphere.

scholarly journals Investigations in the infra-red region of the spectrum. Part II.—The absorption spectrum of sulphur dioxide

1930 ◽  
Vol 130 (812) ◽  
pp. 142-156 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Resolving Power ◽  
Final Word ◽  
Molecular Constants ◽  
Order Of Accuracy ◽  
Moments Of Inertia ◽  
Infra Red ◽  
High Order Of Accuracy ◽  
The Individual ◽  
Band Type

It has been pointed out that if the precautions indicated in the previous paper are carefully observed, a high order of accuracy in infra-red measurements can be obtained with a prism spectrometer. Although the final word at present rests with the grating instrument on account of its higher resolving power, nevertheless a deal of useful work remains to be done with prisms. A band can be located (generally a necessary process for a prism spectrometer before the grating can be applied), the band centre and band type can often be determined, and the molecular constants can be approximately deduced. It is proposed in these papers to examine the spectra of gases and vapours in which the molecure has three different moments of inertia. The rotational fine structure within a vibrational band due to an asymmetrical rotator is very complex and individual lines may lie so close and the constituent series so overlap that absorption may be practically continuous. The prism spectrometer enables the first step in the unravelling of the tangle to be accomplished, in that the envelope of the individual lines gives under favourable circumstances the branches of the Bjerrum doublets, and hence enables the moments of inertia to be determined and frequently provides a knowledge of what may be called the resultant electrical structure of the molecule.

Vibration-rotation bands of methane

1952 ◽  
Vol 213 (1112) ◽  
pp. 42-54 ◽  
Keyword(s):  
Complex System ◽  
Absorption Spectrum ◽  
Fine Structure ◽  
Resolving Power ◽  
Absorption Bands ◽  
Infra Red ◽  
Vibration Rotation

The infra-red absorption spectrum of methane 12 CH 4 in the region of 3 μ has been re-investigated with higher resolving power than has been used previously. A very complex system of overlapping vibration bands has been revealed. The rotational fine structure of these bands has been partially analyzed, particularly having regard to the Coriolis interactions which occur in this case. The corresponding absorption bands of 13 CH 4 have also been examined.

A discussion on infared astronomy - High resolution spectra of the Sun

1969 ◽  
Vol 264 (1150) ◽  
pp. 171-182 ◽  
Keyword(s):  
Near Infrared ◽  
Signal To Noise Ratio ◽  
Solar Spectrum ◽  
Instrumental Function ◽  
Signal To Noise ◽  
Maximum Resolution ◽  
Scientific Station ◽  
Under Construction ◽  
The University ◽  
Absorption Features

The University of Liege has operated, since 1958, a laboratory of solar spectroscopy at the International Scientific Station of the Jungfraujoch (Switzerland). During recent years, much effort has been devoted in two main directions: ( a ) techniques of correction for the effects of the instrumental function to obtain the best possible knowledge of central intensities and profiles of photospheric lines; ( b )increase of the signal to noise ratio in the records in order to detect and measure very faint absorption features. In addition, a balloon-borne equipment is now under construction in Liege to observe, with maximum resolution, the near infrared solar spectrum from an altitude of about 80 000 ft.

scholarly journals Ultra-violet transparency of the lower atmosphere, and relative poverty in Ozone

1918 ◽  
Vol 94 (660) ◽  
pp. 260-268 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Solar Spectrum ◽  
Ultra Violet ◽  
Lower Atmosphere ◽  
Atmospheric Ozone ◽  
Absorption Bands ◽  
Relative Poverty ◽  
Narrow Bands

Many years ago it was suggested by Hartley* that the limit of the solar spectrum towards the ultra-violet was attributable to absorption by atmospheric ozone, which, as he showed, would give rise to a general absorption beginning at about the place where the solar spectrum ends. In a recent paper by Prof. A. Fowler and myself,† the evidence for this view was very much strengthened. For it was shown that just on the limits of extinction the solar spectrum shows a series of narrow absorption bands which are eventually merged in the general absorption, and these narrow bands are precisely reproduced in the absorption spectrum of ozone. For my own part, I do not feel any doubt that ozone in the atmosphere is the effective cause limiting the solar spectrum.

The infra-red absorption spectrum of pentaphenylphosphorane

1964 ◽  
Vol 20 (8) ◽  
pp. 1289-1293 ◽  
Author(s):  
C. Degani ◽  
M. Halmann ◽  
I. Laulicht ◽  
S. Pinchas
Keyword(s):  
Absorption Spectrum ◽  
Infra Red
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