Results 41 to 50 of about 1,279 (175)

Surveys of the Milky Way and Magellanic System in the λ21-cm line of atomic hydrogen

EPJ Web of Conferences, 2012
In the next three years, surveys of the Northern and Southern skies using focal plane arrays on aperture synthesis radio telescopes will lead to a breakthrough in our knowledge of the warm and cool atomic phases of the interstellar medium and their ...
Dickey J.M.
doaj   +1 more source

Galactic Masers

, 2006
Since the discovery of galactic masers in the mid 1960s, their studies have resulted in remarkable deepening of the understanding of physical processes in the interstellar medium and stars.
R. S. Booth
core   +1 more source

Polarization Properties of Astrophysical Masers [PDF]

, 1973
Observed interstellar OH and H2O maser lines at 18 cm and 1.35 cm exhibit unusual polarization properties. The OH emitters with the highest brightness temperatures, usually associated with H II regions, almost always show a high degree of circular ...
Kwan, John Ying-Kuen
core   +1 more source

ALMA Detection of Masers and Dasars in the Hydrogen Recombination Lines of the Planetary Nebula Mz3

The Astrophysical Journal
The hydrogen recombination lines H30 α , H40 α , H42 α , H50 β , and H57 γ and the underlying bremsstrahlung continuum emission were detected with ALMA in the bipolar nebula Mz3.
Zulema Abraham, Pedro P. B. Beaklini, Isabel Aleman, Raghvendra Sahai, Albert Zijlstra, Stavros Akras, Denise R. Gonçalves, Toshiya Ueta   +7 more
doaj   +1 more source

Frequency Standard Contributions to Limitations on the Signal‐to‐Noise Ratio in Very Long Baseline Interferometric Observations

Radio Science, Volume 61, Issue 6, June 2026.
Abstract Since its observation in 2019, the first image of a super‐massive black hole using Very Long Baseline Interferometry (VLBI) with an Earth‐scale baseline has generated much scientific and public interest. Work is now underway to extend the baseline into space to obtain higher image resolution.
E. A. Burt, T. A. Ely, G. C. Bower, T. J. W. Lazio, M. Anderson, S. Hernandez   +5 more
wiley   +1 more source

Deep Space Network Radio Science and Ground‐Based Planetary Radar in the Next Decade

Radio Science, Volume 60, Issue 7, July 2025.
Abstract The Deep Space Network (DSN) has been a core operational element of NASA's crewed and robotic exploration of the Solar System since the early 1960s. The primary role of the DSN has been to acquire telemetry and navigation data, but over the years, its radiometric and radar capabilities have expanded to form a system for obtaining unique ...
R. S. Park, J. E. Riedel, N. Rodriguez‐Alvarez, M. Brozovic, L. A. M. Benner, P. Vergados, D. Buccino, C. S. Jacobs, L. S. Locke, S. W. Asmar, R. Castano, T. J. W. Lazio, J. Jao, C. Lee   +13 more
wiley   +1 more source

Discovery of H2O, CH3OH, and OH Masers in the Extreme Outer Galaxy

, 2018
We present the results of a single dish interstellar maser survey toward similar to 200 molecular clouds. (MCs) in the extreme outer Galaxy. (EOG) possibly lying in the Outer Scutum- Centaurus. (OSC) arm.
Chen, Xi, Henkel, C., Yang, J., Xu, Y., Chen, X., Fang, M., Henkel, Christian, Sun, Yan, Yang, Ji, Xu, Ye, Jiang, Z., Menten, Karl M., Menten, K., Jiang, Zhi-Bo, Sun, Y., Chen, Xue-Peng, Fang, Min   +16 more
core   +1 more source

Interstellar masers as evolutionary tracers of high-mass star formation

, 2010
Determining an evolutionary clock for high-mass star formation is a much sought after result in astrophysics, as it will allow comprehensive quantitative studies of the formation of high-mass stars to be completed. We have carried out detailed studies of
Breen, SL (15931253)
core   +1 more source

5 cm OH Masers in Northern Star Formation Regions

The Astronomical Journal
We present a 6.0 GHz excited-state OH maser survey toward 155 northern star formation regions utilizing the Shanghai Tianma Radio Telescope. In total, we detect 44 6.0 GHz OH masers, 8 of which are new detections (one at 6016 MHz, two at 6030 MHz, and ...
Hai-Hua Qiao, Xu-Jia Ouyang, Zhi-Qiang Shen, Shari L. Breen, Kai Yang, Xi Chen, Juan Li   +6 more
doaj   +1 more source

Chemistry in Interstellar Hydroxyl Maser Regions [PDF]

Symposium - International Astronomical Union, 1987
The pumping of the upper levels of the 2π3/2 J=3/2 state of OH at sufficient rates to account for the observed strengths of interstellar hydroxyl masers requires that OH contains a substantial fraction of the oxygen. Shocks have been suggested as the sites of the OH production, but a better understanding of OH photodissociation and observations of ...
openaire   +1 more source