Results 71 to 80 of about 134,972 (304)

Extragalactic radio surveys in the pre-Square Kilometre Array era [PDF]

Royal Society Open Science, 2017
The era of the Square Kilometre Array is almost upon us, and pathfinder telescopes are already in operation. This brief review summarizes our current knowledge of extragalactic radio sources, accumulated through six decades of continuum surveys at the ...
Chris Simpson
doaj   +1 more source

Jet Interactions with the Hot Halos of Clusters and Galaxies [PDF]

, 2007
X-ray observations of cavities and shock fronts produced by jets streaming through hot halos have significantly advanced our understanding of the energetics and dynamics of extragalactic radio sources.
Birzan, L., Carilli, C., McNamara, B. R., Nulsen, P. E. J., Rafferty, D. A., Wise, M. W.   +5 more
core   +1 more source

Phaseless VLBI mapping of compact extragalactic radio sources

, 2004
The problem of phaseless aperture synthesis is of current interest in phase-unstable VLBI with a small number of elements when either the use of closure phases is not possible (a two-element interferometer) or their quality and number are not enough for ...
A. R. Thompson, A. T. Bajkova, A. T. Bajkova, A. T. Bajkova, A. T. Bajkova, A. T. Bajkova, A. T. Bajkova, A. T. Bajkova, A. V. Oppenheim, J. E. Baldwin, J. E. Baldwin, J. L. C. Sanz, J. R. Fienup, J. R. Fienup, J. R. Fienup, M. H. Hayes, R. Gerchberg, T. B. Pyatunina, Ya. I. Khurgin, Yu. M. Bruck   +19 more
core   +2 more sources

Clusters of Extragalactic Ultra Compact HII Regions [PDF]

, 2001
We report on the detection of optically thick free-free radio sources in the galaxies M33, NGC 253, and NGC 6946 using data in the literature. We interpret these sources as being young, embedded star birth regions, which are likely to be clusters of ...
Bianchi S., Boulesteix J., Courtes G., De Pree C. G., Duric N., Garcia-Gomez C., Henry A. Kobulnicky, Kelsey E. Johnson, Larsen S. S., Peter S. Conti, Philip Massey, Smith L. F., Tarchi A., Weiler K. W., Westerhout G.   +14 more
core   +2 more sources

The Extragalactic Radio Source Background [PDF]

Symposium - International Astronomical Union, 1990
The background of discrete extragalactic radio sources is described from the point of view of its simplest properties: surface density and surface distribution. New considerations, particularly with regard to the latter, open the possibility of detecting Universal structure on many angular scales.
openaire   +1 more source

HEAD IN THE STARS, FEET ON THE GROUND: Scale and Astronomy Initiatives in Southern Africa

Cultural Anthropology, Volume 40, Issue 4, Page 571-596, November 2025.
ABSTRACT This article explores the evolution of radio astronomy in South Africa and Madagascar, focusing on how “scale” functions as both a way of understanding the world and marking differences in existence. In outer space research, the ground is crucial but often overlooked.
HANNA NIEBER, DAVIDE CHINIGÒ
wiley   +1 more source

Deep Synoptic Array Science: Implications of Faraday Rotation Measures of Fast Radio Bursts Localized to Host Galaxies

The Astrophysical Journal Letters, 2023
Faraday rotation measures (RMs) of fast radio bursts (FRBs) offer the prospect of directly measuring extragalactic magnetic fields. We present an analysis of the RMs of 10 as yet nonrepeating FRBs detected and localized to host galaxies with robust ...
Myles B. Sherman, Liam Connor, Vikram Ravi, Casey Law, Ge Chen, Kritti Sharma, Morgan Catha, Jakob T. Faber, Gregg Hallinan, Charlie Harnach, Greg Hellbourg, Rick Hobbs, David Hodge, Mark Hodges, James W. Lamb, Paul Rasmussen, Jun Shi, Dana Simard, Jean Somalwar, Reynier Squillace, Sander Weinreb, David P. Woody, Nitika Yadlapalli, The Deep Synoptic Array Team   +23 more
doaj   +1 more source

Galactic HCO+ Absorption toward Compact Extragalactic Radio Sources

, 2018
As part of the search for the "dark molecular gas (DMG)," we report on the results of HCO$^+$ J = 1-0 absorption observations toward nine bright extragalactic millimeter wave continuum sources. The extragalactic sources are at high Galactic latitudes (|b|
Byun, Do-Young, Heiles, Carl E., Kim, Kee-Tae, Koo, Bon-Chul, Park, Geumsook   +4 more
core   +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

An Extragalactic Widefield Search for Technosignatures with the Murchison Widefield Array

The Astrophysical Journal
It is common for surveys that are designed to find artificial signals generated by distant civilizations to focus on galactic sources. Recently, researchers have started focusing on searching for all other sources within the field observed, including the
C. D. Tremblay, S. J. Tingay
doaj   +1 more source