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The prompt emission mechanism of gamma-ray bursts (GRBs) is still unclear, and the time-resolved spectral analysis of GRBs is a powerful tool for studying their underlying physical processes. We performed a detailed time-resolved spectral…

High Energy Astrophysical Phenomena · Physics 2024-01-29 Wan-Kai Wang , Wei Xie , Zhi-Fu Gao , Shuo Xiao , Ai-Jun Dong , Bin Zhang , Qi-Jun Zhi

Early afterglow observations of gamma-ray bursts (GRBs) are valuable for exploring the properties of their jets and ambient medium. We report our photometric and spectroscopic observations of GRB 210104A and discuss its jet properties with…

High Energy Astrophysical Phenomena · Physics 2022-12-16 Lu-Lu Zhang , Li-Ping Xin , Jing Wang , Xu-Hui Han , Dong Xu , Zi-Pei Zhu , Chao Wu , Jian-Yan Wei , En-Wei Liang

Since the launch of the Fermi Gamma-ray Space Telescope on June 11, 2008, 55 gamma-ray bursts (GRBs) have been observed at coordinates that fall within 66^\circ of the Fermi Large Area Telescope (LAT) boresight with precise localizations…

High Energy Astrophysical Phenomena · Physics 2015-05-20 C. W. Akerlof , W. Zheng , S. B. Pandey , T. A. McKay

Observations with the Swift satellite of X-ray afterglows of more than a hundred gamma ray bursts (GRBs) with known redshift reveal ubiquitous soft X-ray absorption. The directly measured optical depth \tau at a given observed energy is…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Ehud Behar , Shlomo Dado , Arnon Dar , Ari laor

As wireless communication systems continue to grow rapidly, high-performance antennas become increasingly crucial for expanding coverage, improving capacity, and enhancing transmission quality. In light of this, research has focused…

Signal Processing · Electrical Eng. & Systems 2025-12-22 Sasmita Dash , Constantinos Psomas , Ioannis Krikidis

We report on the first Fermi Large Area Telescope (LAT) measurements of the so-called "extra-galactic" diffuse gamma-ray emission (EGB). This component of the diffuse gamma-ray emission is generally considered to have an isotropic or nearly…

High Energy Astrophysical Phenomena · Physics 2010-04-06 LAT collaboration

The Experiment to Detect the Global Epoch of Reionization 21 cm Signal (EDGES) has reported evidence for an absorption feature in the sky-averaged radio background near 78 MHz. A cosmological interpretation of this signal corresponds to…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-30 Alexandra Nelander , Christopher Cain , Jordan C J DSilva , Peter H Sims , Rogier A Windhorst , Judd D Bowman

High Electron Mobility Transistors (HEMTs) are most suitable for harsh environments as they operate reliably under extreme conditions such as high voltages, high temperatures, radiation exposure and corrosive atmospheres. In this article,…

Signal Processing · Electrical Eng. & Systems 2025-10-13 Tanjim Rahman , Trupti Ranjan Lenka

Gamma-ray bursts (GRBs) are intense, short-lived bursts of gamma-ray radiation observed up to a high redshift ($z \sim 10$) due to their luminosities. Thus, they can serve as cosmological tools to probe the early Universe. However, we need…

We observed radio continuum emission in 27 local (D < 70 Mpc) star-forming galaxies with the Robert C. Byrd Green Bank Telescope between 26 GHz and 40 GHz using the Caltech Continuum Backend. We obtained detections for 22 of these galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Katie Rabidoux , D. J. Pisano , Amanda A. Kepley , Kelsey E. Johnson , Dana S. Balser

AGN are known to account for a major portion, if not all, of the cosmic X-ray background radiation. The dominant sharp spectral feature in their spectra is the 6.4 keV fluorescent line of iron, which may contribute to as much as ~ 5-10 % of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Gert Hütsi , Marat Gilfanov , Rashid Sunyaev

After seven years of science operation, the Fermi mission has brought great advances in the study of Gamma-ray Bursts (GRBs). Over 1600 GRBs have been detected by the Gamma-ray Burst Monitor, and more than 100 of these are also detected by…

High Energy Astrophysical Phenomena · Physics 2015-07-19 Elisabetta Bissaldi , Francesco Longo , Nicola Omodei , Giacomo Vianello , Andreas von Kienlin

Abundances of galaxies at redshifts z > 4 are difficult to obtain from damped Ly {\alpha} (DLA) systems in the sightlines of quasars (QSOs) due to the Ly {\alpha} forest blanketing and the low number of high-redshift quasars detected.…

We present observations with the new 11 GHz radiometer of the COSMOSOMAS experiment at the Teide Observatory (Tenerife). The sky region between 0 deg <= RA <= 360 deg and 26 deg <= DEC 49 deg (ca. 6500 square degrees) was observed with an…

Gamma-Ray Transient Monitor (GTM) is an all-sky monitor onboard the Distant Retrograde Orbit-A (DRO-A) satellite, with the scientific objective of detecting gamma-ray bursts in the energy range of 20 keV to 1 MeV. GTM is equipped with five…

The observation of very-high-energy (VHE, $\rm >10~GeV$) $\gamma$-ray emission from $\rm \gamma$-ray bursts (GRBs), especially in the prompt phase, will provide critical information for understanding many aspects of their nature including…

The third-generation South Pole Telescope camera is designed to measure the cosmic microwave background across three frequency bands (95, 150 and 220 GHz) with ~16,000 transition-edge sensor (TES) bolometers. Each multichroic pixel on a…

We present an experimental demonstration of a Laguerre-Gauss (LG) spectrum measurement technique using variable focus lenses that is able to measure the strengths of all modes present in an unknown, incoming light beam with the highest…

The formation of the first stars and galaxies during 'Cosmic Dawn' is thought to have imparted a faint signal onto the 21-cm spin temperature from atomic Hydrogen gas in the early Universe. Observationally, an absorption feature should be…

Instrumentation and Methods for Astrophysics · Physics 2022-11-30 Danny C. Price