scholarly journals The candidates for Class I methanol masers

2021 ◽  
Vol 2103 (1) ◽  
pp. 012012
Author(s):  
A V Nesterenok
Keyword(s):  
Energy Level ◽  
Velocity Gradient ◽  
Chemical Processes ◽  
Class I ◽  
Shock Model ◽  
Collisional Excitation ◽  
Large Velocity ◽  
Methanol Masers ◽  
Essential Chemical ◽  
Large Velocity Gradient

Abstract The collisional excitation of methanol molecule in non-dissociative magnetohydro-dynamic shock waves is considered. All essential chemical processes that determine methanol abundance in the gas are taken into account in the shock model. The large velocity gradient approximation is used in the calculations of energy level populations of the molecule. We calculate the optical depth for inverted methanol transitions, and present the list of candidates for Class I methanol masers that have collisional pumping mechanism.

scholarly journals Effect of variation in density on the stability of superposed streams of Fluid

1931 ◽  
Vol 132 (820) ◽  
pp. 499-523 ◽  
Keyword(s):  
Density Gradient ◽  
Velocity Gradient ◽  
Horizontal Plane ◽  
Experimental Results ◽  
Large Velocity ◽  
Formed Part ◽  
The Stability ◽  
Large Velocity Gradient

1. The chief part of the work described in this paper was done in 1914 and formed part of the essay for which the Adams Prize was awarded in 1915. During the war years it was laid aside, and since then I have delayed publica­tion, hoping to be able to undertake experiments designed to verify, or otherwise, the results. Lately, however, Mr. Goldstein has told me that he is engaged on similar problems and he has encouraged me to publish the work without waiting for experimental results. It is well known that when the wind near the ground drops at night owing to the cooling of the ground, the wind at a higher level frequently remains unchanged so that the effect of a decrease in density with height is to enable a large velocity gradient to be maintained. This implies that the turbulence is suppressed or at any rate much reduced by the density gradient. To the mathematician this at once presents the problem of the stability of a fluid in which the density and velocity vary with height above the ground, regarded as a horizontal plane.

On the motion of particles in a fluid under the influence of a large velocity gradient

1993 ◽  
Vol 14 (1-2) ◽  
pp. 42-48 ◽  
Author(s):  
P. J. Thomas ◽  
K. -A. Bütefisch ◽  
K. H. Sauerland
Keyword(s):  
Velocity Gradient ◽  
Large Velocity ◽  
Large Velocity Gradient

scholarly journals Discovery of large-scale masers in W3(OH)

2006 ◽  
Vol 2 (S237) ◽  
pp. 422-422
Author(s):  
L. Harvey-Smith ◽  
R. J. Cohen
Keyword(s):  
Velocity Gradient ◽  
Large Scale ◽  
Velocity Structure ◽  
Central Star ◽  
Line Profiles ◽  
Maser Emission ◽  
Methanol Maser ◽  
Large Velocity ◽  
Structure Line ◽  
Large Velocity Gradient

AbstractWe report a vast filament of hydroxyl and methanol maser emission surrounding the ultra-compact HII region W3(OH). The filament stretches 3100 AU and has a linear velocity gradient. By studying the velocity structure, line profiles and extended methanol maser structures we believe we have located the position of the central star and detected around it a circumstellar disc with a large velocity gradient of 47 km s−1 arcsec−1.

scholarly journals SN 2017hpa: A Nearby Carbon-rich Type Ia Supernova with a Large Velocity Gradient

2021 ◽  
Vol 909 (2) ◽  
pp. 176
Author(s):  
Xiangyun Zeng ◽  
Xiaofeng Wang ◽  
Ali Esamdin ◽  
Craig Pellegrino ◽  
WeiKang Zheng ◽  
...  
Keyword(s):  
Velocity Gradient ◽  
Type Ia Supernova ◽  
Large Velocity ◽  
Type Ia ◽  
Large Velocity Gradient
Sign in / Sign up

Export Citation Format

Share Document