Results 51 to 60 of about 4,855 (170)
Astrophysical constraints on the proton-to-electron mass ratio with FAST
, 2019 That the laws of physics are the same at all times and places throughout the Universe is one of the basic assumptions of physics. Astronomical observations provide the only means to test this basic assumption on cosmological time and distance scales. The
Chen, Xi, Ellingsen, Simon P., Mei, Ying
core +1 more source
Radiative Transport in Interstellar Masers
The 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.
openaire +1 more source
VLBI observations of interstellar ammonia masers
The 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
Preethi Pratap +4 more
openaire +1 more source
Masers and Star Formation Activities in W51A
The Astronomical JournalConcurrently with the maser flare observed in W51-North during the 3 month monitoring of H _2 O, NH _3 , and CH _3 OH maser variability from 2020 January to April using the Tianma 65 m Radio Telescope, we conducted Very Large Array mappings for these ...
Yan-Kun Zhang +5 more
doaj +1 more source
Maser action in methanol transitions
, 2005 We report the detection with the ATCA of 6.7 GHz methanol emission towards OMC-1. The source has a size between 40'' and 90'', is located to the south-east of Ori-KL and may coincide in position with the 25 GHz masers.
A.M. Sobolev +13 more
core +1 more source
Sun-Sized Water Vapor Masers in Cepheus A [PDF]
, 2018 We present the first VLBI observations of a Galactic water maser (in Chepeus A) made with a very long baseline interferometric array involving the RadioAstron Earth-orbiting satellite station as one of its elements. We detected two distinct components at
Alakoz, A. +8 more
core +3 more sources
The Sizes of 1720 MHz OH Masers: VLBA and MERLIN Observations of the Supernova Remnants W44 and W28 [PDF]
, 1999 We have used the NRAO Very Long Baseline Array (VLBA) to image OH(1720 MHz) masers in the supernova remnants W28 and W44 at a resolution of 40 mas. We also used MERLIN to observe the same OH(1720 MHz) masers in W44 at a resolution of 290 x 165 mas.
D. A. Frail +6 more
core +2 more sources
Pumping the interstellar (6, 3) ammonia maser
The Astrophysical Journal, 1991 A numerical model of the excitation of ammonia in dense interstellar clouds predicts strong maser emission in various inversion doublet lines when infrared pumping to the lowest vibrationally excited state is included. Specifically the (6,3) transition mases, while the (5,3) and (4,3) transitions are in normal emission, as observed in W51.
Ronald D. Brown, Dinah M. Cragg
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Enhanced density and magnetic fields in interstellar OH masers [PDF]
Astronomy & Astrophysics, 2006 19 pages including online material, accepted to A& ...
Fish, Vincent L. +3 more
openaire +2 more sources
A 6 cm Formaldehyde Line Survey toward WISE Point Sources
The Astrophysical Journal Supplement SeriesWe conducted a 6 cm formaldehyde (H _2 CO) line survey across the northern sky, targeting 3149 high-mass star-forming region candidates selected from the all-sky Wide-field Infrared Survey Explorer (WISE) point-source catalog using the Shanghai TianMa 65
Jun-Ting Liu +8 more
doaj +1 more source