On the combined Doppler and pressure broadening of nonresonant spectral lines

1988 ◽  
Vol 66 (4) ◽  
pp. 341-348
Author(s):  
M. A. Diaz ◽  
F. Palomares ◽  
J. Veguillas
Keyword(s):  
Kinetic Equation ◽  
Inelastic Collisions ◽  
Spectral Lines ◽  
The Other ◽  
Low Density ◽  
Doppler Broadening ◽  
Equation Approach ◽  
Pressure Broadening ◽  
Debye Relaxation ◽  
Collision Model

An explicit spectral function for nonresonant transitions has been derived that includes pressure broadening, Doppler broadening, and diffusional narrowing. This has been accomplished through a kinetic-equation approach. The kinetic equation has been resolved by using an extension of the Bhatnagar–Gross–Krook collision model to inelastic collisions, characterized by two collision frequencies: one associated with elastic collisions and the other associated with inelastic ones. The high- and low-density limits have been discussed, and the standard formula for Debye relaxation has been reproduced. Finally, a discussion concerning the above aspects and their possible extensions has been included as well.

scholarly journals Functional study of a monoclonal antibody to IgE Fc receptor (Fc epsilon R2) of eosinophils, platelets, and macrophages.

1986 ◽  
Vol 164 (1) ◽  
pp. 72-89 ◽  
Author(s):  
M Capron ◽  
T Jouault ◽  
L Prin ◽  
M Joseph ◽  
J C Ameisen ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
B Lymphocyte ◽  
Specific Binding ◽  
Polyclonal Antibodies ◽  
Fc Receptor ◽  
The Other ◽  
Functional Study ◽  
Low Density ◽  
Fluorescence Staining ◽  
Ige Binding

An IgM mAb (BB10) was produced by immunization of mice with human eosinophils purified according to their abnormal low density ("hypodense" cells), and previously shown to exhibit increased IgE-dependent antiparasite cytotoxicity. This BB10 antibody, selected for positive fluorescence staining of hypodense blood or lung eosinophils and low or negative staining of normodense eosinophils or neutrophils, could strongly inhibit IgE-dependent cytotoxicity of human eosinophils and platelets. The specificity for the IgE Fc receptor was suggested by the high levels of inhibition of IgE rosettes formed by eosinophils after incubation with the purified IgM fraction of BB10, whereas other receptors (Fc gamma R, CR1) were not affected. On the other hand, BB10, able to inhibit rat eosinophil Fc epsilon R, did not react with the IgE Fc receptor on mast cells or basophils. A technique using radioiodinated BB10 allowed us to quantify the specific binding of BB10 to human eosinophils and platelets. Competition experiments revealed a crossinhibition between the binding of BB10 and IgE, suggesting the specificity of BB10 for the IgE binding site of eosinophil, platelet, and monocyte Fc epsilon R. Three proteins having extrapolated Mr of 32,000, 43,000-45,000, and 97,000 were found in the platelet extract eluted from a BB10 or from an IgE immunosorbent column. These findings confirm the similarities between IgE Fc receptors on human eosinophils, platelets, and macrophages, already observed with polyclonal antibodies directed against the B lymphocyte Fc epsilon receptor. They suggest, moreover, that the mAb BB10 can represent a good reagent for further investigations on the structure and the functions of this IgE Fc receptor (Fc epsilon R2).

scholarly journals Kinetic-equation approach to diffusive superconducting hybrid devices

1996 ◽  
Vol 53 (21) ◽  
pp. 14496-14505 ◽  
Author(s):  
T. H. Stoof ◽  
Yu. V. Nazarov
Keyword(s):  
Kinetic Equation ◽  
Equation Approach ◽  
Hybrid Devices

THE EFFECT OF COLLISIONS ON THE DOPPLER BROADENING OF SPECTRAL LINES

1967 ◽  
Vol 9 (5) ◽  
pp. 701-716 ◽  
Author(s):  
Sergei G Rautian ◽  
Igor I Sobel'man
Keyword(s):  
Spectral Lines ◽  
Doppler Broadening

scholarly journals Star cluster formation in Orion A

2020 ◽  
Author(s):  
Wanggi Lim ◽  
Fumitaka Nakamura ◽  
Benjamin Wu ◽  
Thomas G Bisbas ◽  
Jonathan C Tan ◽  
...  
Keyword(s):  
Cluster Formation ◽  
Star Cluster ◽  
The Other ◽  
Young Stellar Objects ◽  
Molecular Gas ◽  
Archival Data ◽  
Formation Processes ◽  
Collision Process ◽  
Stellar Objects ◽  
Collision Model

Abstract We introduce new analysis methods for studying the star cluster formation processes in Orion A, especially examining the scenario of a cloud–cloud collision. We utilize the CARMA–NRO Orion survey 13CO (1–0) data to compare molecular gas to the properties of young stellar objects from the SDSS III IN-SYNC survey. We show that the increase of $v_{\rm {}^{13}CO} - v_{\rm YSO}$ and Σ scatter of older YSOs can be signals of cloud–cloud collision. SOFIA-upGREAT 158 μm [C ii] archival data toward the northern part of Orion A are also compared to the 13CO data to test whether the position and velocity offsets between the emission from these two transitions resemble those predicted by a cloud–cloud collision model. We find that the northern part of Orion A, including regions ONC-OMC-1, OMC-2, OMC-3, and OMC-4, shows qualitative agreements with the cloud–cloud collision scenario, while in one of the southern regions, NGC 1999, there is no indication of such a process in causing the birth of new stars. On the other hand, another southern cluster, L 1641 N, shows slight tendencies of cloud–cloud collision. Overall, our results support the cloud–cloud collision process as being an important mechanism for star cluster formation in Orion A.

Profiles of Pressure Broadened Spectral Lines in an Arc Plasma

2005 ◽  
Vol 60 (10) ◽  
pp. 727-735
Author(s):  
Reda A. El-Koramy ◽  
Abd El-Halim A. Turky
Keyword(s):  
Alkali Metals ◽  
Stark Effect ◽  
Point Of View ◽  
Spectral Lines ◽  
Pressure Broadening ◽  
Static Approximation ◽  
Pressure Line ◽  
Pressure Profiles ◽  
Impact Approximation ◽  
Quadratic Stark Effect

Spectral analysis of the alkali metals is characterized by pressure profiles. In the present work an electric arc has been used to calibrate the half-width of the intensity used in the construction of the ArI natural line at 4300 Å with a trace of evaporated rubidium at pressures of 1, 2 and 3 atmospheres. The results agree well with those obtained by Kusch’s line absorption equation in an electric furnace in the point of view of impact approximation, showing that the widths of the lines have Lorentz shapes. It is found that a simple treatment can be given using the quasi-static approximation of pressure broadening developed by Unsöld. The agreement of the results is good only if the shifts are large. The study shows that the pressure line profile is made up of a sum of dispersion profiles and asymmetric terms which arise from interactions of quadratic Stark effect, commonly assumed to be the force in causing foreign gas broadening

scholarly journals Observations of [OI]63 μm line emission in main-sequence galaxies at z ∼ 1.5

2020 ◽  
Vol 499 (2) ◽  
pp. 1788-1794
Author(s):  
J Wagg ◽  
M Aravena ◽  
D Brisbin ◽  
I Valtchanov ◽  
C Carilli ◽  
...  
Keyword(s):  
Field Strength ◽  
Interstellar Medium ◽  
Radiation Field ◽  
Uv Radiation ◽  
Main Sequence ◽  
Line Emission ◽  
The Other ◽  
Low Density ◽  
Star Forming ◽  
Neutral Gas

ABSTRACT We present Herschel–PACS spectroscopy of four main-sequence star-forming galaxies at z ∼ 1.5. We detect [OI]63 μm line emission in BzK-21000 at z = 1.5213, and measure a line luminosity, $L_{\rm [O\, {\small I}]63\, \mu m} = (3.9\pm 0.7)\times 10^9$ L⊙. Our PDR modelling of the interstellar medium in BzK-21000 suggests a UV radiation field strength, G ∼ 320G0, and gas density, n ∼ 1800 cm−3, consistent with previous LVG modelling of the molecular CO line excitation. The other three targets in our sample are individually undetected in these data, and we perform a spectral stacking analysis which yields a detection of their average emission and an [O i]63 μm line luminosity, $L_{\rm [O\, {\small I}]63\, \mu m} = (1.1\pm 0.2)\times 10^9$ L⊙. We find that the implied luminosity ratio, $L_{\rm [O\, {\small I}]63\, \mu m}/L_{\rm IR}$, of the undetected BzK-selected star-forming galaxies broadly agrees with that of low-redshift star-forming galaxies, while BzK-21000 has a similar ratio to that of a dusty star-forming galaxy at z ∼ 6. The high [O i]63 μm line luminosities observed in BzK-21000 and the z ∼ 1−3 dusty and sub-mm luminous star-forming galaxies may be associated with extended reservoirs of low density, cool neutral gas.

General Theory of Pressure Broadening of Spectral Lines

1945 ◽  
Vol 68 (3-4) ◽  
pp. 78-93 ◽  
Author(s):  
Alexander Jabloński
Keyword(s):  
General Theory ◽  
Spectral Lines ◽  
Pressure Broadening

Reply to “Comment on ‘Model kinetic equation for low-density granular flow’ ”

1998 ◽  
Vol 57 (5) ◽  
pp. 6212-6213 ◽  
Author(s):  
J. J. Brey ◽  
F. Moreno ◽  
James W. Dufty
Keyword(s):  
Kinetic Equation ◽  
Granular Flow ◽  
Low Density ◽  
Model Kinetic Equation
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