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1.
The paper presents the effect of O3 depletion on OH (8,3) band. It is shown that Bates-Nicolet theory for the excitation of OH band is predominant excitation process. Calculations based on chemical kinetics show that the intensity of OH (8,3) band will also be effected due to the depletion of O3 concentration. O3 is depleted everywhere specially at Antarctica. Intensity of OH (8,3) band is calculated theoretically for Halley Bay (76° S, 27° W), British Antarctic survey station during the period 1973 to 1984.  相似文献   

2.
Nine plates of the 7883-Å CO2 band were taken between phase angles 7.2 and 10.7° in 1971. A curve-of-growth analysis of 28 rotational lines in the band indicates an average rotational temperature of 236 ± 8°K; the average slope of the curve of growth was 0.63 ± 0.06. The results for this band are compared to those for the 7820-Å band.  相似文献   

3.
W. Macy 《Icarus》1980,41(1):153-158
Matching computed spectra for the ν4 band of methane, the ν9 band of ethane, and the R branch of the ν5 band of acetylene to observed spectra for Neptune suggests mixing ratios of CH4/H2 ～ 10?3?10?2, C2H6/H2 ～ 10?6, and C2H2/H2 ～ 10?8 in the stratosphere.  相似文献   

4.
Douglas B. Nash 《Icarus》1983,54(3):511-523
The role of adsorbed SO2 on Io's surface particles in producing the observed spectral absorption band near 4 μm in Io's reflectance spectrum is explored. Calculations show that a modest 50% monolayer coating of adsorbed SO2 molecules on submicron grains of sulfur of alkali sulfide, assumed to make up Io's uppermost optical surface (“radialith”), will result in a ν1 + ν3 absorption band near 4 μm with depth ～30% below the adjacent continuum, consistent with the observed strength of the Io band. The precise wavelength position of the ν1 + ν3 band of SO2 in different phase states such as frost, ice, adsorbate, and gas are summarized from the experimental literature and compared with the available telescopic measurements of the Io band position. The results suggest that the 4-μm band in Io's full disk spectrum can best be explained by the presence on Io's surface of widespread SO2 in the form of adsorbate rather than ice or frost.  相似文献   

5.
Phase curves for the CO2 bands at 7883, 7820, and 8689 Å are presented. While the weaker bands at 7820 and 7883 Å show a definite “inverse phase effect,” the band at 8689 Å shows a more normal phase curve; it also exhibited much larger day-to-day variations in the CO2 abundance near superior conjunction in 1971. Because the variation of the phase curves with band strength is comparable to temporal variations on Venus, simultaneous observations of strong and weak bands are still needed to determine the dependence on band strength accurately.  相似文献   

6.
F.W. Taylor  A.D. Jones 《Icarus》1976,29(2):299-306
We present some results of a theoretical and laboratory program to determine the thermal infrared spectral properties of the principal gaseous constituents of the atmosphere of Jupiter. G. Birnbaum has measured laboratory spectra in the 16 to 1000 um wavelength range for hydrogen and hydrogen-helium mixtures at Jovian temperatures. These are compared to theoretically computed spectra in order to determine the temperature dependence of the line strengths in the pressure-induced rotational band and the overlap parameters from the translational band. Existing spectral data for methane do not agree well with measurements of the ν4 band at room temperature. A revised allocation of line intensities is proposed. Existing data for the ν2 (10 um) band of ammonia do agree reasonably well with measurements at room temperature and at ?77δC, but there are some important discrepancies which remain to be explained.  相似文献   

7.
It is shown that the 10–13 μ band observed in the spectra of some carbon stars could arise from simple hydrocarbon molecules, especially of the type C n H 2n . These molecules could be present in circumstellar dust shells which are responsible for the 1000 K black-body excess observed for these stars, and the emission band is produced by collisional excitation.  相似文献   

8.
George Ohring 《Icarus》1975,24(3):388-394
The concept is described of deducing the temperature and constituent profile of a planetary atmosphere from orbiter measurements of the planet's ir limb radiance profile. Expressions are derived for the weighting functions associated with the limb radiance profile for a Goody random band model. Analysis of the weighting functions for the Martian atmosphere indicates that a limb radiance profile in the 15 μm CO2 band can be used to determine the Martian atmospheric temperature profile from 20 to 60 km. Simulation of the Martian limb radiance profile in the rotational water vapor band indicates that Martian water vapor mixing ratios can be inferred from limb radiance observations in a water vapor band.  相似文献   

9.
The spectral variations of three Mira variable carbon stars, V CrB, T Dra and V Cyg in the infrared are investigated based on ISO SWS data. It is found that either continua or molecular/dust features were variable with time in the infrared for these carbon stars during one and a half year observations. When stars were brighter the infrared continuum spectra became blue while stars were fainter the infrared continuum spectra became red. In addition, during spectral variations there were the correlation between the 3.05 μm HCN+C2H2 and the 5.2 μm C3 molecular band strengths and the anti-correlation between the 3.05 μm HCN+C2H2 molecular band strengths and 13.7 μm C2H2 band strengths while during variations the 11.3 μm SiC dust emission strengths were not clearly changed.  相似文献   

10.
The questionable existence of C2 absorption lines in spectra of sunspots was checked: In two umbral spectra of large single sunspots evidence for the presence of lines of the (0, 0) band and of the (0, 1) band was found.  相似文献   

11.
We present the discovery of a new vibrational band system of isotopic CO2 (carbon dioxide) near 3.3 μm, with multiple strong P, Q and R lines in the prime spectral region used to search for Mars CH4 (methane). The band system was discovered on Mars using high-resolution spectrometers (λ/δλ>40,000, CSHELL and NIRSPEC) at telescopes (NASA-IRTF and Keck-2) atop Mauna Kea, HI. The observed line intensities and frequencies agree very well with values predicted by a vibrational band model that we developed using known parameters for the molecular levels involved. Using this model, we synthesized spectra for different observing conditions (from Space and ground-based telescopes) and for different spectral resolving powers (5000 to 40,000). Although the total atmospheric burden on Mars is more than 150 times smaller than on Earth, the greater mixing ratio of CO2 ensures that its column abundance on Mars is almost 20 times greater than on Earth. Thus, weak telluric CO2 band systems appear much stronger on Mars. Many molecules of possible biological and geothermal interest have strong signatures at these wavelengths, in particular hydrocarbons owing to their strong ro-vibrational CH stretching modes. For example, the new isotopic CO2 band-system encompasses lines of CH4, C2H6 (ethane), CH3OH (methanol) and H2O (water). Implications for previous and future searches of biomarker gases are presented.  相似文献   

12.
Band models for CO2 and H2O absorption are described, and used to model the Venera 11 spectra near 1 μm. An effective-path approximation is used to allow for scattering in the clouds. The model has 10 layers and uses 211 CO2 and 15 H2O vibrational transitions, at 5 cm? resolution. Within a factor of 2, a maximum absorption in the 0.94-μm H2O band just below the clouds, corresponding to 200 ppm by volume, in agreement with V. I. Moroz, N. A. Parfen'ev, and N. F. San'ko (1979, Cosmic Res. 17, 601–614) is found. More accurate band strenghts are needed to model the bottom scale height accurately. The possibility that the 0.94-μm feature is blended with a band of some other molecule has been examined. Ten possible chemical species were examined, with negative results.  相似文献   

13.
A laboratory discharge lamp is described which strongly emits the forbidden OI 5577 and 6300 Å lines and the O2 (0?0) atmospheric band. Experimental measurements confirm that these atomic and molecular species are in thermal equilibrium with one another, so that a rotational temperature measurement of the O2 atmospheric band allows one to deduce the line widths of the 5577 and 6300 Å emissions. This thus provides a useful calibration source for interferometric measurements of these emissions.  相似文献   

14.
Forty-seven well exposed photographic plates of Venus which show the spectrum of the carbon dioxide band at 7820Å were obtained at Table Mountain Observatory in September and October 1972. These spectra showed a semiregular four-day variation in the CO2 abundance over the disk of the planet (Young et al., 1974). We also find evidence for temporal variations in the rotational temperature of this band and temperature variations over the disk. The two quantities, CO2 abundance and temperature, do not show any obvious relationship; however, an increase in the temperature usually is accompanied by a decrease in the abundance of CO2. The average temperature, found from a curve-of-growth analysis assuming a constant CO2 line width, is 249±1.4K (one standard deviation). This temperature is noticeably higher than the rotational temperature of 242±2K found for this same band in 1967 (Schorn et al., 1969) and of 242±1.2K in 1968–1969 (Young et al., 1971).  相似文献   

15.
We have calculated the expected equivalent widths of the individual rotational lines of the Lyman band of H2 and (A-X) band of CO and SiO for Main Sequence stars. The results indicate that the lines of H2 should be observable in absorption up toT e9000 K. The lines of CO are found to be much weaker than those of H2 lines. A discussion of these results is presented.  相似文献   

16.
The visibility in the umbral ultraviolet spectrum of the O2 Schumann-Runge absorption band system has been explored. It is found that the band system may be visible in high dispersion sunspot spectrum.  相似文献   

17.
Nine plates of the 7820 Å CO2 band were taken in 1971. A curve-of-growth analysis of the CO2 lines indicates a rotational temperature of 241 ± 2°K, with an average slope to the curve of growth of 0.60 ± 0.03. The Venus phase angle ranged from 7.2 to 10.7°. The equivalent widths of the 1971 data fall on a smooth curve fit through the 1969 data for this band; there does not appear to be any discontinuity in the phase curve at small phase angles.  相似文献   

18.
Relationships between organic molecules and inorganic minerals are investigated in a single 34 μm diameter grain of the CR2 chondrite Northwest Africa 852 (NWA) 852 with submicron spatial resolution using synchrotron‐based imaging micro‐FTIR spectroscopy. Correlations based on absorption strength for the various constituents are determined using statistical correlation analysis. The silicate band is found to be correlated with the hydration band, and the latter is highly correlated with stretching modes of aliphatic hydrocarbons. Spatial distribution maps show that water+organic combination, silicate, OH, and C‐H distributions overlap, suggesting a possible catalytic role of phyllosilicates in the formation of organics. In contrast, the carbonate band is anticorrelated with water+organic combination, however uncorrelated with any other spectral feature. The average ratio of asymmetric CH2 and CH3 band strengths (CH2/CH3 = 2.53) for NWA 852 is similar to the average ratio of interplanetary dust particles (~2.40) and Wild 2 cometary dust particles (2.50), but it significantly exceeds that of interstellar medium objects (~1.00) and several aqueously altered carbonaceous chondrites (~1.40). This suggests organics of similar length/branching, and perhaps similar formation regions, for NWA 852, Wild 2 dust particles, and interplanetary dust particles. The heterogeneous spatial distribution of ratio values indicates the presence of a mixture of aliphatic organic material with different length/branching, and thus a wide range of parent body processes, which occurred before the considered grain was formed.  相似文献   

19.
We observed Mrk 421 in V and R band using the 1.0 m telescope at Weihai Observatory of Shandong University since 2009 April to 2012 May. The available historical data in B and V band were also assembled for constructing light curves. The brightness of Mrk 421 ranges from 11.40 to 16.14 in the B band light curve, and from 11.38 to 14.56 in the V band. Analyses with the Jurkevich method and the structure function method showed a possible period of about 1.36 years for its long periodic variability. This period could be explained by a close binary black hole system (BBHS) model with a primary black hole mass of 1.70×108 M ⊙ and a secondary ～(0.49–2.9)×107 M ⊙. We showed the color variability of Mrk 421, a bluer when brighter behavior during its lower state. Analyses of spectral index variations show that only a host galaxy contribution is not sufficient to explain the spectral index variations in Mrk 421, and some intrinsic mechanism is needed.  相似文献   

20.
Frank-Condon factors for H2O+ bands have been calculated. They are used to estimate the photon scattering coefficient g8.0 for the (8,0) band at 6158 Å.  相似文献   

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