Related papers: GPS in the cosmos
Fully relativistic coordinates have been proposed for (relativistically) running a "GPS" system. These coordinates are the arrival times of the light signals emitted by four "satellites" (clocks). Replacing the signals emitted by four…
The discovery of radio pulsars over a half century ago was a seminal moment in astronomy. It demonstrated the existence of neutron stars, gave a powerful observational tool to study them, and has allowed us to probe strong gravity, dense…
Since their first discovery in the late 1960s, Gamma-ray bursts have attracted an exponentially growing interest from the international community due to their central role in the most highly debated open questions of the modern research of…
Gamma-Ray Bursts (GRBs) are believed to originate in compact remnants (black holes or neutron stars) of massive stars. Their high luminosities make them detectable out to the edge of the visible universe. We describe the many advantages of…
With its immensity and numerous mysteries waiting to be solved, the cosmos has always captivated humankind. A ground-breaking field that has given us a profound understanding of the mysteries of the cosmos is radio astronomy. This paper…
We revisit the shocked shell model for the class of Active Galactic Nuclei known as Gigahertz Peak Spectrum sources, incorporating new observational data on the radiation brightness temperatures. We argue that in addition to free-free…
We present the first broadband X-ray observations of four Giga-Hertz Peaked Spectrum (GPS) radio galaxies at redshift <~1 performed by Chandra and XMM-Newton. These observations more than double the number of members of this class with…
We have explored, in the general framework of the ``young source'' scenario, evolutionary models for GHz Peaked Spectrum (GPS) galaxies and quasars which reproduce the observed counts, redshift and peak frequency distributions of currently…
Despite an intense theoretical and experimental effort over the past decade, observations of the extragalactic radio background at multiple frequencies below 10 GHz are not understood in terms of known radio sources, and may represent a…
We propose that Gigahertz Peak Spectrum (GPS) and Compact Steep Spectrum (CSS) radio sources are the signposts of relativistic jet feedback in evolving galaxies. Our simulations of relativistic jets interacting with a warm, inhomogeneous…
Pulsar astronomy is currently enjoying one of the most productive phases in its history. In this review, I outline some of the basic observational aspects and summarise some of the latest results of searches for pulsars in the disk of our…
Galaxy groups constitute the most common class of galaxy systems in the known Universe, unique in terms of environmental properties. However, despite recent advances in optical and infrared observations as well as in theoretical research,…
The issue of radiation mechanisms had triggered in 1950-60s the first applications of plasma physics to understand the nature of radio galaxies. This interplay has steadily intensified during the past five decades, due to the premise of…
Arcminute-resolution radio continuum images at 408 and 1420 MHz from the Canadian Galactic Plane Survey (CGPS) have been used to reexamine radio sources listed in the Kallas and Reich (1980) catalogue. This catalogue is of particular…
Giant radio sources (GRSs) defined to be > 0.7 Mpc are the largest single objects in the Universe and can be associated with both galaxies (GRGs) and quasars (GRQs). They are important for understanding the evolution of radio galaxies and…
According to the currently accepted paradigm compact steep spectrum (CSS) sources are precursors of larger/older objects and gigahertz peaked spectrum (GPS) sources may be earlier stages of CSS sources. In this paper we confront this…
A new class of X-ray sources was clearly established with the discovery of highly relativistic radio jets from the galactic sources GRS 1915+105 and GRO J1655-40. Both of these objects have given us a broader view of black holes and the…
Gas can be used to trace the formation and evolution of galaxies as well as the impact that the nuclear activity has on the surrounding medium. For nearby compact radio sources, we have used observations of neutral hydrogen - that we…
Gigahertz Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) sources are compact radio galaxies (RGs), with jets extending up to 20 kpc and ages <10^3 years. They are considered to evolve to Fanaroff-Riley RGs, but the real scenario to…
Studies of nearby galaxies including the Milky Way have provided fundamental information on the evolution of structure in the Universe, the existence and nature of dark matter, the origin and evolution of galaxies, and the global features…