Related papers: An Ultra-long Wavelength Sky Model with Absorption…
We present an investigation of the properties of the extended Ly$\alpha$ halo and the large-scale \ion{H}{I} absorbing structures associated with 5 high-redshift radio galaxies at z $>$ 2, using the Goodman long-slit spectrograph on the…
Extended 21cm absorption regions (dubbed ``21cm absorption halos'') around first galaxies at $z\sim 30$ are likely the first distinctive structures accessible to radio observations. Though the radio array capable of detecting and resolving…
Recent Spitzer observations have revealed a substantial population of z~2 ULIRGs with deep silicate absorption (\tau_{9.7}>1). This paper reports a 20cm radio study of such a sample to elucidate their physical nature. We discover that a…
In the framework of the study of extragalactic radio sources, we will focus on the importance of the spatial resolution at different wavelengths, and of the combination of observations at different frequency bands. In particular, a…
Physical sizes of extended radio galaxies can be employed as a cosmological "standard ruler", using a previously developed method. Eleven new radio galaxies are added to our previous sample of nineteen sources, forming a sample of thirty…
Our understanding of the universe relies mostly on electromagnetism. As photons are the messengers, fundamental physics is concerned in testing their properties. Photon mass upper limits have been earlier set through pulsar observations,…
The Molonglo Observatory Synthesis Telescope, operating at 843 MHz with a 5 square degree field of view, is carrying out a radio imaging survey of the sky south of declination -30 deg. This survey (the Sydney University Molonglo Sky Survey,…
This paper introduces a new program to find high-redshift radio galaxies in the southern hemisphere through ultra-steep spectrum (USS) selection. We define a sample of 234 USS radio sources with spectral indices alpha_408^843 < -1.0 and…
Low-frequency spectral studies of radio pulsars represent a key method for uncovering their emission mechanisms, magnetospheric structure, and signal interactions with the surrounding interstellar medium (ISM). In recent years, more…
Building the radio sky template are crucial for detecting the 21 cm emission line signal from the Epoch of Reionization (EoR), as well as for other cosmological research endeavors. Utilizing data from the LOFAR Two-meter Sky Survey (LoTSS)…
The largely unexplored decameter radio band (10-30 MHz) provides a unique window for studying a range of astronomical topics, such as auroral emission from exoplanets, inefficient cosmic ray acceleration mechanisms, fossil radio plasma, and…
A very efficient method to measure the flux of Ultra-high energy (UHE) neutrinos is through the detection of radio waves which are emitted by the particle shower in the lunar regolith. The highest acceptance is reached for radio waves in…
A redshifted 21 cm line absorption signature is commonly expected from the cosmic dawn era, when the first stars and galaxies formed. The detailed traits of this signal can provide important insight on the cosmic history. However, high…
We have obtained very deep near-infrared images in the fields of 10 QSOs whose spectra contain damped Lyman-alpha absorption (DLA) systems with 1.7<z_abs <2.5. The main aim of our investigation is to provide new constraints on the…
In this paper, a route to ultra-broadband absorption is suggested and demonstrated by a feasible design. The high absorption regime (absorption above 90%) for the suggested structure ranges from visible to mid-infrared (MIR), i.e. for the…
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…
I review the development of UV and EUV astronomy, covering the spectral range from 5 to 300 nm, with emphasis on sky surveys for discrete sources. I discuss studies which resulted in lists of sources observed by imaging. The missions are…
A search for HI absorption has been made in 23 radio galaxies using the ATCA, the VLA and the WSRT. In five galaxies HI absorption was detected. We investigate how the detection rate is distributed among galaxies with different radio and…
Deep submillimetre surveys have successfully detected distant, star-forming galaxies, enshrouded in vast quantities of dust and which emit most of their energy at far infrared wavelengths. These luminous galaxies are an important…
With the low Earth orbit environment becoming increasingly populated with artificial satellites, rockets, and debris, it is important to understand the effects they have on radio astronomy. In this work, we undertake a multi-frequency,…