Results 11 to 20 of about 4,855 (170)

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, K. P. Johns, P. D. Godfrey, R. D. Brown   +3 more
openaire   +3 more sources

Sample and Statistical Analysis of the Near-Earth Object Wide-field Infrared Survey Explorer Variability of the 6.7 GHz Methanol Maser Sources

The Astrophysical Journal Supplement Series, 2023
We present a statistical study of infrared variability using the Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) database for a sample consisting of 1085 high-mass young stellar objects (YSOs) related to 6.7 GHz methanol masers.
Shi-Min Song, Xi Chen, Zhi-Qiang Shen, You-Xin Wang, Kai Yang, Dan Miao, Jiong-Heng Wu, Jun-Ting Liu, Yan-Kun Zhang   +8 more
doaj   +1 more source

Interstellar methanol masers [PDF]

Symposium - International Astronomical Union, 1993
The asymmetric rotor molecule methanol (CH3OH) has hundreds of transitions at centimeter-, millimeter-, and submillimeter wavelengths. Many of these are excited in the hot (T ≳ 150 K), dense (n ≳ 106 cm−3) molecular cloud cores surrounding newly formed massive stars or protostars.
openaire   +1 more source

New interstellar masers in nonmetastable ammonia

The Astrophysical Journal, 1986
The published version is located at http://adsabs.harvard.edu/full/1986ApJ...300L ...
MADDEN, SC, Irvine, William M., MATTHEWS, HE, BROWN, RD, GODFREY, PD   +4 more
openaire   +2 more sources

Physical Environments of the Luminosity Outburst Source NGC 6334I Traced by Thermal and Maser Lines of Multiple Molecules

The Astrophysical Journal Supplement Series, 2023
We have conducted a systematic line survey, primarily focused on transitions of the methanol and ammonia molecules, and monitoring observations of masers toward the high-mass star-forming region NGC 6334I.
Jiong-Heng Wu, Xi Chen, Yan-Kun Zhang, Simon P. Ellingsen, Andrej M. Sobolev, Zhang Zhao, Shi-Ming Song, Zhi-Qiang Shen, Bin Li, Bo Xia, Rong-Bin Zhao, Jing-Qing Wang, Ya-Jun Wu   +12 more
doaj   +1 more source

QCL‐based frequency metrology from the mid‐infrared to the THz range: a review

Nanophotonics, Volume 8, Issue 2, Page 181-204, June 2018., 2018
Abstract Quantum cascade lasers (QCLs) are becoming a key tool for plenty of applications, from the mid‐infrared (mid‐IR) to the THz range. Progress in related areas, such as the development of ultra‐low‐loss crystalline microresonators, optical frequency standards, and optical fiber networks for time and frequency dissemination, is paving the way for ...
Luigi Consolino, Francesco Cappelli, Mario Siciliani de Cumis, Paolo De Natale   +3 more
wiley   +1 more source

RadioAstron space-VLBI project: studies of masers in star forming regions of our Galaxy and megamasers in external galaxies [PDF]

, 2017
Observations of the masers in the course of RadioAstron mission yielded detections of fringes for a number of sources in both water and hydroxyl maser transitions. Several sources display numerous ultra-compact details. This proves that implementation of
Alakoz, A. V., Baan, W. A., Shakhvorostova, N. N., Sobolev, A. M.   +3 more
core   +1 more source

Variability of Interstellar Water Vapor Masers [PDF]

Highlights of Astronomy, 1998
We present some results of observations of H2O masers (1.35 cm line) in Star-Forming Regions. The observations have been made from the beginning of the eighties at the 22 m radiotelescope at Pushchino, Russia (Lekht et al. 1995). The time interval between two consecutive observations is about one month.
J.E. Mendoza-Torres, E.E. Lekht
openaire   +1 more source

Exact Relativistic Magnetized Haloes around Rotating Disks

Advances in Mathematical Physics, Volume 2015, Issue 1, 2015., 2015
The study of the dynamics of magnetic fields in galaxies is one of important problems in formation and evolution of galaxies. In this paper, we present the exact relativistic treatment of a rotating disk surrounded by a magnetized material halo. The features of the halo and disk are described by the distributional energy‐momentum tensor of a general ...
Antonio C. Gutiérrez-Piñeres, Abraão J. S. Capistrano, Klaus Kirsten   +2 more
wiley   +1 more source

RadioAstron probes the ultra-fine spatial structure in the H$_2$O maser emission in the star forming region W49N [PDF]

, 2019
H$_2$O maser emission associated with the massive star formation region W49N were observed with the Space-VLBI mission RadioAstron. The procedure for processing of the maser spectral line data obtained in the RadioAstron observations is described.
Alakoz, A. V., Avdeev, V. Y., Imai, H., Moran, J. M., Shakhvorostova, N. N., Sobolev, A. M.   +5 more
core   +1 more source