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We present the results of a programme of scanning and mapping observations of astronomical masers and Jupiter designed to characterise the performance of the Mopra Radio Telescope at frequencies between 16-50 GHz using the 12-mm and 7-mm…

A possible explanation for the central abundance dips found from spatially-resolved X-ray spectroscopy of several groups and clusters of galaxies is resonance scattering. A number of the prominent iron emission lines are resonance lines. We…

Astrophysics · Physics 2009-09-17 J. S. Sanders , A. C. Fabian

Interaction of a frequency-chirped laser pulse with single protons and a hydrogen plasma cell is studied analytically and by means of particle-in-cell simulations, respectively. Feasibility of generating ultra-intense (10^7 particles per…

A photonics-assisted microwave pulse detection and frequency measurement scheme is proposed. The unknown microwave pulse is converted to the optical domain and then injected into a fiber loop for pulse replication, which makes it easier to…

Applied Physics · Physics 2022-03-09 Pengcheng Zuo , Dong Ma , Qingbo Liu , Lizhong Jiang , Yang Chen

The excitation of radial and longitudinal wake-fields by two co-propagating chirped laser pulses in a rippled, magnetized plasma has been examined. This study aimed to clarify the spatiotemporal evolution of wake structures and assess their…

Plasma Physics · Physics 2026-04-28 A. A. Molavi Choobini , F. M. Aghamir

Images taken by space telescopes typically have a superb spatial resolution, but a relatively poor sampling rate due to the finite CCD pixel size. Beyond the Nyquist limit, it becomes uncertain how much the pixelation effect may affect the…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-06 Zhi Shen , Jun Zhang , Hekun Li , Haoran Wang , Chengliang Wei , Guoliang Li , Xiaobo Li , Zhang Ban , Dan Yue

It may be possible to construct a laser interferometer gravitational wave antenna in space with $h_{rms}\sim 10^{-27}$ at $ f\sim 0.1{\rm Hz}$ in this century. We show possible specification of this antenna which we call DECIGO. Using this…

Astrophysics · Physics 2009-11-07 Naoki Seto , Seiji Kawamura , Takashi Nakamura

In general relativistic magneto-hydrodynamic (GRMHD) simulations, accreted magnetic flux on the black hole horizon episodically decays, during which magnetic reconnection heats up the plasma near the horizon, potentially powering…

High Energy Astrophysical Phenomena · Physics 2023-09-26 He Jia , Bart Ripperda , Eliot Quataert , Christopher J. White , Koushik Chatterjee , Alexander Philippov , Matthew Liska

Relativistic amplification boosts the contribution of the jet base to the total emission in blazars, thus making single dish observations useful and practical to characterise their physical state, particularly during episodes of enhanced…

Instrumentation and Methods for Astrophysics · Physics 2020-01-15 Marcello Giroletti , Simona Righini

After new observations of 39 galaxies at z = 0.6-1.0 obtained at the IRAM 30m telescope, we present our full CO line survey covering the redshift range 0.2 < z < 1. Our aim is to determine the driving factors accounting for the steep…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 F. Combes , S. Garcia-Burillo , J. Braine , E. Schinnerer , F. Walter , L. Colina

We present new constraints on the relationship between galaxies and their host dark matter halos, measured from the location of the peak of the stellar-to-halo mass ratio (SHMR), up to the most massive galaxy clusters at redshift $z\sim0.8$…

The advent of high-average-power, ultrafast ytterbium-based lasers allows us to generate laser filaments at repetition rates ranging from 10s of kHz up to 100s of kHz. At such high repetition rates, the inter-pulse time lies below the time…

Optics · Physics 2025-06-04 Robin Löscher , Malte C. Schroeder , Alan Omar , Clara J. Saraceno

We report on the realization of an all-fiber laser source that delivers single-frequency pulses at 1645 nm, on a linearly polarized single-mode beam, based on stimulated Raman scattering in passive fibers. The pulse energy reaches 14…

Single-cavity dual-comb lasers are a new class of ultrafast lasers which have a wide possible application space including pump-probe sampling, optical ranging, and gas absorption spectroscopy. However, to this date laser cavity multiplexing…

This paper primarily investigates the effect of the tilt of corner cube reflector (CCR) arrays on lunar laser ranging (LLR). A mathematical model was established to study the random errors caused by the tilt of the CCR arrays. The study…

Instrumentation and Methods for Astrophysics · Physics 2024-08-22 Jin Cao , Rufeng Tang , Kai Huang , Zhulian Li , Yongzhang Yang , Kai Huang , Jintao Li , Yuqiang Li

All gravitational-wave observatories (GWOs) have been using the laser wavelength of 1064 nm. Ultra-stable laser devices are at the sites of GEO 600, Kagra, LIGO and Virgo. Since 2019, not only GEO 600 but also LIGO and Virgo have been using…

We use the Spitzer Wide-area InfraRed Extragalactic Legacy Survey (SWIRE) to explore the specific star-formation activity of galaxies and their evolution near the peak of the cosmic far-infrared (FIR) background at 70 and 160um. We use a…

It has long been believed that accretion onto supermassive black holes powers quasars, but there has been relatively few observational constraints on the spins of the black holes. We address this problem by estimating the average radiative…

Astrophysics · Physics 2009-11-11 Jian-Min Wang , Yan-Mei Chen , Luis C. Ho , Ross J. McLure

Recent studies of galaxies in the local Universe, including those in the Local Group, find that the efficiency of environmental (or satellite) quenching increases dramatically at satellite stellar masses below ~ $10^8\ {\rm M}_{\odot}$.…

We report the results on theoretical investigation about possible simultaneous laser generation in all, closely spaced modes of chirped photonic crystals layer in all visible region of the spectrum. With the possible ability to control the…

Optics · Physics 2022-08-15 A. H. Gevorgyan , N. A. Vanyushkin , I. M. Efimov
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