Results 1 to 10 of about 147 (135)
Pumping the interstellar methanol masers [PDF]
Monthly Notices of the Royal Astronomical Society, 1992 The pumping of interstellar methanol masers is studied, covering a range of excitation conditions. The Class I (Class A) masers result from collisional excitation followed by spontaneous radiative decay. Masers appear in low-frequency transitions where the upper state is strongly favoured by large Einstein A coefficients, associated with high-frequency
D M Cragg
exaly +2 more sources
New interstellar masers in nonmetastable ammonia
Astrophysical Journal, 1986 The published version is located at http://adsabs.harvard.edu/full/1986ApJ...300L ...
H E Matthews, W M Irvine
exaly +3 more sources
Variability of interstellar hydroxyl masers
Astrophysical Journal, 1991 The spectra of 10 interstellar OH maser complexes were monitored in the 1665 MHz transition for variability on short (minutes-hours) and long (days-years) time scales. Eight of the sources exhibit short time scale variability in the relative amplitudes of the spectral features above that expected due to radiometer noise, and all sources for which ...
James Cordes
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Enhanced density and magnetic fields in interstellar OH masers [PDF]
Astronomy and Astrophysics, 2006 19 pages including online material, accepted to A& ...
Karl Menten, Mark Reid
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Radiative Transport in Interstellar Masers
Astrophysical Journal, 1973 d bandwidth of emission from OH and H/sub 2/O maser spheres that are expanding or contracting and that are homogeneously or inhomogenously pumped. Amplification of resonant acatter is shown to be less important than that of spontaneous emission in detemnining the small apparent interferometer sizes of emitters.
M M Litvak
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VLBI observations of interstellar ammonia masers
Astrophysical Journal, 1991 The first VLBI measurement of interstellar ammonia masers is reported. The positions, as well as size and brightness temperature limits, for the masers in the NH 3 (9, 6) inversion transition that are associated with the ultracompact H II regions W51 e1 and e2 are obtained. The masers arise from two positions, each of which is located close to but not
Karl Menten, Mark Reid, James Moran
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Broadband VLA Spectral-line Survey of a Sample of Ionized Jet Candidates
The Astrophysical Journal Supplement Series, 2023 The study of the interaction between ionized jets, molecular outflows, and their environments is critical to understanding high-mass star formation, especially because jets and outflows are thought to be key in the transfer of angular momentum outward ...
E. Sanchez-Tovar +4 more
doaj +1 more source
Proper Motions of Water Masers in W49 N Measured by KaVA
The Astrophysical Journal, 2023 We report the proper motions of 22 GHz water masers toward W49 N that were observed by the KVN and VERA Array (KaVA) during 2017 February–May. We found 263, 268, and 310 features in three successive epochs; they were distributed in a region of size 4 × 4
Kitiyanee Asanok +8 more
doaj +1 more source
NAVIGATION, Volume 68, Issue 4, Page 687-708, Winter 2021., 2021 Abstract A server satellite that is parked in a stable distant retrograde orbit (DRO) in the vicinity of the Moon can provide navigation service for satellites in the Earth–Moon system. In this study, X‐ray pulsar navigation (XPNAV) is investigated to determine the server's orbital position and velocity, and maintain its onboard timing autonomously to ...
Jiangkai Liu +4 more
wiley +1 more source
FIRST INTERSTELLAR HCO + MASER [PDF]
The Astrophysical Journal, 2012 4 pages, 3 figures, accepted by ApJL on September 10 ...
Hakobian, Nicholas S. +1 more
openaire +2 more sources