A CASPT2 study of the spectral shift of the resonance emission lines of Rb and Cs embedded in liquid He

2016 ◽  
Vol 655-656 ◽  
pp. 91-95 ◽  
Author(s):  
Lucas Modesto-Costa ◽  
Prasanta Kumar Mukherjee ◽  
Sylvio Canuto
Keyword(s):  
Spectral Shift ◽  
Emission Lines ◽  
Resonance Emission

scholarly journals IUE Observations of Z Andromedae

1980 ◽  
Vol 88 ◽  
pp. 543-546
Author(s):  
M. Friedjung
Keyword(s):  
Emission Lines ◽  
Close Binary ◽  
Line Of Sight ◽  
Symbiotic Star ◽  
High Excitation ◽  
Dilution Factor ◽  
Preliminary Results ◽  
Upper Limit ◽  
Resonance Emission ◽  
Joint Study

The preliminary results of a joint study of this symbiotic star with 6 Italian astronomers are reported. The relative intensities of the intercombination emission lines indicate electron densities of 1010 and an upper limit to the dilution factor between 10−4 and 10−6. The resonance emission lines give a maximum thickness in the line of sight. A hot (T between 19000° and 26000°) continuum is interpreted as coming from a hot subdwarf, but the high excitation emission lines appear to be formed near the cool giant component of what is probably a close binary.

scholarly journals Effects of Eccentric Orbit of BF Cygni on IUE and Optical Spectra

1988 ◽  
Vol 103 ◽  
pp. 299-300
Author(s):  
J. Mikolajewska ◽  
M. Mikolajewski
Keyword(s):  
Emission Measure ◽  
Line Emission ◽  
Optical Spectra ◽  
Emission Lines ◽  
Recent Analysis ◽  
Emission Region ◽  
Galactic Rotation ◽  
Resonance Emission ◽  
High Ionization ◽  
Cosmic Abundance

A recent analysis of all available photometric data has resulted in a new ephemeris for BF Cyg: MIN=JD 2415058 + 756.8E. Simultaneously, optical spectra collected in 1979–1986 showed periodic changes of all emission lines (Mikolajewska 1987; Mikolajewska & lijima 1987). It is interesting that the forbidden lines of [OIII] varied in antiphase to the permitted emission lines and optical brightness.IUE spectra taken in 1979–1981 showed a strong hot continuum and high ionization resonance emission lines of NV, SilV CIV, intercombination lines of NIV], NIII], SiIII], CIII] and OIII] as well as Hell emission. The observed λ2200Å interstellar absorption band suggests E(B-V)≃0.3. Taking into account the interstellar reddening distribution in the vicinity of BF Cyg (Lucke 1978; Mikolajewska & Mikolajewski 1980), the observed extinction implies a distance d≲1.5kpc. This distance is in good agreement with the observed low value of the systemic radial velocity (∼15 km/s, Fig.1) of BF Cyg and the standard galactic rotation law. The standard extinction curve with E(B-V)=0.3 (Seaton 1979) was used for reddening correction of the spectra. The UV continuum of BF Cyg can be interpreted as a combination of a hot subdwarf (Teff≃60000K, L≃2500L⊙ for d=1.5kpc) and hydrogen bf+ff emission (Te≃10000K). The emission measure of the nebular (bf+ff) continuum varied from ∼4×1059cm−3 at maximum to ∼1059cm−3 at minimum. Assuming cosmic abundance of Si/C the observed SiIII]/CIII] line ratio implies ne≃2×l010cm−3 at the photometric maximum and ne≃3×109cm−3 at the minimum. We assume that these values are representative of the region where the bulk of the HI Balmer and intercombination line emission is produced. The ratio of NV(1240)/NIV(1720) gives Te(NV)≃11500K close to the value derived for the Balmer emission region from the UV continuum fit.

scholarly journals Kernresonanz-Emissionslinien während rascher Radikalreaktionen

1967 ◽  
Vol 22 (10) ◽  
pp. 1556-1562 ◽  
Author(s):  
J. Bargon ◽  
H. Fischer
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Dynamic Nuclear Polarization ◽  
Nuclear Polarization ◽  
Emission Lines ◽  
Radical Reactions ◽  
Dynamic Coupling ◽  
Correct Order ◽  
Chemically Induced ◽  
Resonance Emission ◽  
Order Of Magnitude

Previously observed nuclear magnetic resonance emission lines of products of rapid radical reactions are explained by chemically induced dynamic nuclear polarization. This polarization occurs after the production of radicals by the dynamic coupling between radical electrons and protons, and it is transfered to the products by the secondary reaction. A theoretical analysis shows that this concept leads to a correct order of magnitude calculation of the intensity of emission. New experiments are described the results of which support the explanation. It is concluded that chemically induced dynamic nuclear polarization is not restricted to the systems treated so far but may occur in other investigations also.

scholarly journals Dust Formation and the Doubly-Periodic Variable Stars

1995 ◽  
Vol 155 ◽  
pp. 196-197
Author(s):  
T. Lloyd Evans
Keyword(s):  
Dust Cloud ◽  
Variable Stars ◽  
Emission Lines ◽  
Circumstellar Dust ◽  
Dust Formation ◽  
Circumstellar Envelope ◽  
Pulsation Period ◽  
Deep Minimum ◽  
Resonance Emission ◽  
Semiregular Variable

AbstractThe doubly-periodic semiregular variable V Hydrae became redder and developed resonance emission lines and bands during the 1992-94 deep minimum, which therefore resulted from the production of a circumstellar dust cloud. This removes the need to postulate a secondary pulsation period, ten times as long as the main pulsation period, in the stellar as opposed to circumstellar envelope.

Long-term Cyclic Variations of Prominences, Green and Red Coronae over Solar Cycles

2000 ◽  
Vol 179 ◽  
pp. 201-204
Author(s):  
Vojtech Rušin ◽  
Milan Minarovjech ◽  
Milan Rybanský
Keyword(s):  
Emission Lines ◽  
High Latitudes ◽  
Green Line ◽  
Solar Cycles ◽  
The South ◽  
Coronal Emission ◽  
Local Maxima ◽  
The North ◽  
Cyclic Variations

AbstractLong-term cyclic variations in the distribution of prominences and intensities of green (530.3 nm) and red (637.4 nm) coronal emission lines over solar cycles 18–23 are presented. Polar prominence branches will reach the poles at different epochs in cycle 23: the north branch at the beginning in 2002 and the south branch a year later (2003), respectively. The local maxima of intensities in the green line show both poleward- and equatorward-migrating branches. The poleward branches will reach the poles around cycle maxima like prominences, while the equatorward branches show a duration of 18 years and will end in cycle minima (2007). The red corona shows mostly equatorward branches. The possibility that these branches begin to develop at high latitudes in the preceding cycles cannot be excluded.

The "spectral shift" phenomenon of chloroquine

1966 ◽  
Vol 93 (1) ◽  
pp. 123-128 ◽  
Author(s):  
W. M. Sams
Keyword(s):  
Spectral Shift

A Hydrogen Bond Between Linear Tetrapyrrole and Conserved Aspartate Causes the Far-Red Shifted Absorption of Phytochrome Photoreceptors

2020 ◽  
Author(s):  
Egle Maximowitsch ◽  
Tatiana Domratcheva
Keyword(s):  
Hydrogen Bond ◽  
Light Adaptation ◽  
Positive Charge ◽  
Pyrrole Ring ◽  
Md Simulations ◽  
Spectral Shift ◽  
Specific Domain ◽  
Study Guides ◽  
Rational Engineering ◽  
Tuning Mechanism

Photoswitching of phytochrome photoreceptors between red-absorbing (Pr) and far-red absorbing (Pfr) states triggers light adaptation of plants, bacteria and other organisms. Using quantum chemistry, we elucidate the color-tuning mechanism of phytochromes and identify the origin of the Pfr-state red-shifted spectrum. Spectral variations are explained by resonance interactions of the protonated linear tetrapyrrole chromophore. In particular, hydrogen bonding of pyrrole ring D with the strictly conserved aspartate shifts the positive charge towards ring D thereby inducing the red spectral shift. Our MD simulations demonstrate that formation of the ring D–aspartate hydrogen bond depends on interactions between the chromophore binding domain (CBD) and phytochrome specific domain (PHY). Our study guides rational engineering of fluorescent phytochromes with a far-red shifted spectrum.

Modeling of Hydrogen Emission Lines in the Spectrum of UX Ori in Its Bright State and during Eclipses

2020 ◽  
Vol 64 (12) ◽  
pp. 1026-1041
Author(s):  
L. V. Tambovtseva ◽  
V. P. Grinin ◽  
D. V. Dmitriev
Keyword(s):  
Emission Lines ◽  
Hydrogen Emission ◽  
Hydrogen Emission Lines

scholarly journals Line observations of the 30-Dor complex and N159A5 with the MPE imaging NIR spectrometer FAST

1991 ◽  
Vol 148 ◽  
pp. 205-206 ◽  
Author(s):  
A. Krabbe ◽  
J. Storey ◽  
V. Rotaciuc ◽  
S. Drapatz ◽  
R. Genzel
Keyword(s):  
Spatial Resolution ◽  
Molecular Hydrogen ◽  
Near Infrared ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Emission Lines ◽  
Resolving Power ◽  
Max Planck ◽  
First Time ◽  
Infrared Array

Images with subarcsec spatial resolution in the light of near-infrared atomic (Bry) and molecular hydrogen H2 (S(1) v=1-0) emission lines were obtained for some extended, pointlike objects in the Large Magellanic Cloud (LMC) for the first time. We used the Max-Planck-Institut für extraterrestrische Physik (MPE) near-infrared array spectrometer FAST (image scale 0.8”/pix, spectral resolving power 950) at the ESO/MPI 2.2m telescope, La Silla. We present some results on the 30-Dor complex and N159A5.

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