Results 41 to 50 of about 38,529 (262)

Powerful Radio Sources in the Southern Sky. III. First Results of the Optical Spectroscopic Campaign

The Astrophysical Journal Supplement Series
We recently built the G4Jy-3CRE catalog of extragalactic radio sources. This catalog lists 264 powerful radio sources selected with similar criteria to those of the revised Third Cambridge Catalog, but visible from the Southern Hemisphere.
A. García-Pérez, H. A. Peña-Herazo, A. Jimenez-Gallardo, V. Chavushyan, F. Massaro, S. V. White, A. Capetti, B. Balmaverde, W. R. Forman, C. C. Cheung, J. P. Madrid, C. Mazzucchelli, N. P. H. Nesvadba, I. Andruchow, S. Cellone, R. Grossová, A. Paggi, E. Sani, V. Reynaldi, R. P. Kraft, C. Leto   +20 more
doaj   +1 more source

Radar Polarimetry in Glaciology: Theory, Measurement Techniques, and Scientific Applications for Investigating the Anisotropy of Ice Masses

Reviews of Geophysics, Volume 63, Issue 4, December 2025.
Abstract Dielectric anisotropy in ice alters the propagation of polarized radio waves, so polarimetric radar sounding can be used to survey anisotropic properties of ice masses. Ice anisotropy is either intrinsic, associated with ice‐crystal orientation fabric (COF), or extrinsic, associated with material heterogeneity, such as bubbles, fractures, and ...
Benjamin H. Hills, T. J. Young, David A. Lilien, Esther Babcock, Nicole Bienert, Donald Blankenship, John Bradford, Giancorrado Brighi, Alex Brisbourne, Jørgen Dall, Reinhard Drews, Olaf Eisen, M. Reza Ershadi, Tamara A. Gerber, Nicholas Holschuh, Daniela Jansen, Thomas M. Jordan, Nanna B. Karlsson, Jilu Li, Carlos Martín, Kenichi Matsuoka, Daniel May, Falk M. Oraschewski, John Paden, Nicholas M. Rathmann, Neil Ross, Dustin M. Schroeder, Martin Siegert, Matthew R. Siegfried, Emma Smith, Ole Zeising   +30 more
wiley   +1 more source

A Comparative Study of VTEC Estimates Derived From S/X VLBI and VGOS Observations

Space Weather, Volume 23, Issue 12, December 2025.
Abstract The ionosphere, which strongly varies in time and space, is one of the largest error sources for microwave measurements, if not accounted for accurately. Especially for single‐frequency observations, precise ionospheric models are needed to correct for the ionospheric delays. This study explores the utility of Very Long Baseline Interferometry
Arno Rüegg, Grzegorz Kłopotek, Benedikt Soja   +2 more
wiley   +1 more source

THE IMAGES OF EXTRAGALACTIC RADIO SOURCES IN THE DIFFUSION MODEL

Odessa Astronomical Publications, 2017
The distribution of the spectral index and radio lobes' isophots were derived by numerical methods in the diffusion model of extragalactic radio sources. The kinetic equation for the distribution function of relativistic electrons is considered.
F. M. Kolesnikov, V. M. Kontorovich
doaj   +1 more source

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

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

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

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

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