Results 51 to 60 of about 544 (185)

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

Populations of Extragalactic Radio Sources [PDF]

Australian Journal of Physics, 1994
In the late 1950s and early 1960s, radio sky surveys were the centre of an intense and public debate-Big-Bang versus Steady-State cosmology-the arguments revolving about source counts and statistical interpretations in the face of instrumental complications.
openaire   +1 more source

The Cosmic Evolution of Fast Radio Bursts Inferred from the CHIME/FRB Baseband Catalog 1

The Astrophysical Journal
Redshift and luminosity distributions are essential for understanding the cosmic evolution of extragalactic objects and phenomena, such as galaxies, gamma-ray bursts, and fast radio bursts (FRBs).
Om Gupta, Paz Beniamini, Pawan Kumar, Steven L. Finkelstein   +3 more
doaj   +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

Counts of Extragalactic Radio Sources [PDF]

Australian Journal of Physics, 1961
In this paper a formula is derived giving the cumulative totals of class II radio sources, to successive limits of flux density, when changes in the space· density and in the radiative properties of these sources are taken into account.
openaire   +1 more source

Probing extreme black‐hole outflows on short timescales via high spectral‐resolution x‐ray imagers

Astronomische Nachrichten, Volume 345, Issue 6-7, July-August 2024.
Abstract We investigate outflows and the physics of super‐Eddington versus sub‐Eddington regimes in black hole systems. Our focus is on prospective science using next‐generation high‐resolution soft x‐ray instruments. We highlight the properties of black hole ultraluminous x‐ray source (ULX) systems in particular. Owing to scale invariance in accreting
C. Pinto, J. F. Steiner, A. Bodaghee, P. Chakraborty, M. Sobolewska, D. R. Pasham, A. Ogorzalek, J. Zuhone, A. Bogdan, M. Vogelsberger   +9 more
wiley   +1 more source

Radio Afterglows from Tidal Disruption Events: An Unbiased Sample from ASKAP RACS

The Astrophysical Journal
Late-time (∼a year) radio follow-up of optically discovered tidal disruption events (TDEs) is increasingly resulting in detections at radio wavelengths, and there is growing evidence for this late-time radio activity to be common to the broad class of ...
Akash Anumarlapudi, Dougal Dobie, David L. Kaplan, Tara Murphy, Assaf Horesh, Emil Lenc, Laura Driessen, Stefan W. Duchesne, Hannah Dykaar, B. M. Gaensler, Timothy J. Galvin, Joe Grundy, George Heald, Aidan W. Hotan, Minh Huynh, James K. Leung, David McConnell, Vanessa A. Moss, Joshua Pritchard, Wasim Raja, Kovi Rose, Gregory Sivakoff, Yuanming Wang, Ziteng Wang, Mark H. Wieringa, Matthew T. Whiting   +25 more
doaj   +1 more source

A Formation Mechanism for “Wrong Way” Radio Relics

The Astrophysical Journal Letters, 2023
Radio relics are typically found to be arc-like regions of synchrotron emission in the outskirts of merging galaxy clusters, bowing out from the cluster center.
Ludwig M. Böss, Ulrich P. Steinwandel, Klaus Dolag   +2 more
doaj   +1 more source

JWST imaging of the closest globular clusters—I. Possible infrared excess among white dwarfs in NGC 6397

Astronomische Nachrichten, Volume 345, Issue 6-7, July-August 2024.
Abstract We present James Webb Space Telescope observations of the globular cluster NGC 6397 and use them to extend to infrared wavelengths the characterization of the cluster's entire white dwarf (WD) cooling sequence (CS). The data allows us to probe fundamental astrophysical WD properties and to search for evidence in their colors for (or against ...
L. R. Bedin, D. Nardiello, M. Salaris, M. Libralato, P. Bergeron, A. J. Burgasser, D. Apai, M. Griggio, M. Scalco, J. Anderson, R. Gerasimov, A. Bellini   +11 more
wiley   +1 more source

DYNAMIC CHARACTERISTICS OF THE MAIN INDEXES OF SPACE WEATHER AND THEIR APPLICATION TO THE ANALYSIS MONITORING OBSERVATIONS FLUX DENSITIES OF POWER RADIO SOURCES ON RT <URAN-4>

Odessa Astronomical Publications, 2012
On radio telescope "URAN-4" of the Odessa observatory of Radio-astronomical Institute during twenty five years (since 1987 till present) monitoring of power galactic and extragalactic radio sources on frequencies 25 and 20MHz has been carried out.
L. Guglya, M. Ryabov, S. Panishko, A. Suharev   +3 more
doaj   +1 more source