Pumping cycles of cosmic masers: sense and methods of investigation

1989 ◽  
Vol 310 (4) ◽  
pp. 343-345 ◽  
Author(s):  
A. M. Sobolev
Keyword(s):  
Cosmic Masers

Cosmic masers

1974 ◽  
Vol 113 (7) ◽  
pp. 463 ◽  
Author(s):  
V.S. Strel'nitskii
Keyword(s):  
Cosmic Masers

Stars, planets, and cosmic masers

1997 ◽  
Vol 167 (10) ◽  
pp. 1131
Author(s):  
V.I. Slysh
Keyword(s):  
Cosmic Masers

scholarly journals IAU (Maser) Symposium 287 Summary

2012 ◽  
Vol 8 (S287) ◽  
pp. 506-515 ◽  
Author(s):  
Karl M. Menten
Keyword(s):  
South Africa ◽  
Rio De Janeiro ◽  
State Of The Art ◽  
The State ◽  
Cosmic Masers ◽  
The Usa

Almost exactly twenty years ago, the first of a series of conferences dedicated to cosmic masers took place in Arlington, Virginia in the USA (March 9–11, 1992). Two more followed, each on a different continent, in Mangaratiba, near Rio de Janeiro, Brasil (March 5–10, 2001) and in Alice Springs, Australia (March 12–16, 2007). As at all others, a large part of the international maser community convened from January 29 to February 3, 2012 in splendid Stellenbosch, South Africa, to discuss the state of the art of the field.

scholarly journals Recent developments in maser theory

2007 ◽  
Vol 3 (S242) ◽  
pp. 7-16
Author(s):  
Moshe Elitzur
Keyword(s):  
Black Holes ◽  
Time Variability ◽  
Fundamental Constants ◽  
Cosmic Masers ◽  
Recent Developments

AbstractThis review covers selected developments in maser theory since the previous meeting,Cosmic Masers: From Proto-Stars to Black Holes(Migenes & Reid 2002). Topics included are time variability of fundamental constants, pumping of OH megamasers and indicators for differentiating disks from bi-directional outflows.

scholarly journals Observations of Cosmic Masers

1988 ◽  
Vol 129 ◽  
pp. 213-222
Author(s):  
P. J. Diamond
Keyword(s):  
Late Type ◽  
Star Forming ◽  
Maser Spot ◽  
Star Forming Regions ◽  
Vlbi Observations ◽  
Cosmic Masers ◽  
Interstellar Scattering

A review is presented of recent results from interferometric observations of cosmic masers. Several topics will be discussed, including MERLIN/VLA/VLBI observations of megamasers; recent results on masers in star forming regions and around late-type stars and some new results on the effects of interstellar scattering on maser spot sizes.

scholarly journals Pumping of Strong H2O Cosmic Masers

1980 ◽  
Vol 87 ◽  
pp. 591-592
Author(s):  
V. S. Strelnitsky
Keyword(s):  
Energy Source ◽  
Flux Density ◽  
Cross Section ◽  
Rotational Level ◽  
Line Of Sight ◽  
Number Density ◽  
Pump Rate ◽  
Cosmic Masers ◽  
Strong Source ◽  
Source And Sink

All the existing models of H2O masers fail to explain such a strong source as W49 N. Observed and theoretical quantities are related by: nH2OWPℓ3 ≳ 1046 S, where S is the maser flux density (in Janskys), nH2O is the H2O number density (cm−3), Wp is pump rate (s−1), and ℓ is the length of amplification region on the line of sight (cm). Models involving vibrational activation (or deactivation) of H2O by H2 (Goldreich and Kwan, 1974; Norman and Silk, 1979), with the usual cross-section σν ≲ 10−19cm2, require ℓ > 1016 cm for the strongest H2O features (∼104 Jy), which is unacceptable in view of the VLBI results. Besides, because σν is so small, it is questionable if vibrational pumping could control rotational level populations at all. Depending on the energy source and sink there are four possible schemes of rotational pumping: CR, RC, RR, and CC (C - collisional, R - radiative). The first was modelled by de Jong (1973) and by Shmeld et al. (1976). Though difficulties with the sink (Goldreich and Kwan, 1974; 1979) are avoidable in the model by Shmeld et al. (Strelnitsky, 1979), ℓ ≳ 1015 − 1016 cm is still required for the strongest features. Therefore other possibilities of rotational pumping are being investigated. One CC-model is presented below.

Stars, planets, and cosmic masers

1997 ◽  
Vol 40 (10) ◽  
pp. 1079-1079
Author(s):  
V I Slysh
Keyword(s):  
Cosmic Masers
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