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The statistical properties of coherent radiation scattered from phase-ordering materials are studied in detail using large-scale computer simulations and analytic arguments. Specifically, we consider a two-dimensional model with a…

Statistical Mechanics · Physics 2009-10-30 Gregory Brown , Per Arne Rikvold , Mark Sutton , Martin Grant

Advanced adaptive optics (AO) instruments on ground-based telescopes require accurate knowledge of the atmospheric turbulence strength as a function of altitude. This information assists point spread function reconstruction, AO temporal…

We have developed a novel detector, referred to as an "$\alpha$-ToF detector", for correlated measurements of atomic masses and decay properties of low-yield, short-lived radioactive isotopes using a multi-reflection time-of-flight mass…

Instrumentation and Detectors · Physics 2020-01-08 T. Niwase , M. Wada , P. Schury , H. Haba , S. Ishizawa , Y. Ito , D. Kaji , S. Kimura , H. Miyatake , K. Morimoto , K. Morita , M. Rosenbusch , H. Wollnik , T. Shanley , Y. Benari

Baryon Acoustic Oscillations (BAO) involve measuring the spatial distribution of galaxies to determine the growth rate of cosmic structure. We derive constraints on cosmological parameters from $17$ uncorrelated BAO measurements that were…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-10 David Benisty , Denitsa Staicova

Adaptive optics (AO) system performance is improved using post-processing techniques, such as point spread function (PSF) deconvolution. The PSF estimation involves characterization of the different wavefront (WF) error sources in the AO…

Instrumentation and Methods for Astrophysics · Physics 2018-08-29 Florian Ferreira , Eric Gendron , Gérard Rousset , Damien Gratadour

The data from the QSO absorption lines indicating a nonzero time-variability of the fine-structure constant has been re-analyzed on the basis of a "damped-oscillator" fit, as motivated by the same type of behavior of a scalar field,…

Astrophysics · Physics 2015-06-24 Yasunori Fujii

Endeavours of the unification of the four fundamental interactions have resulted in a development of theories having cosmological solutions in which low-energy limits of fundamental physical constants vary with time. The validity of such…

Astrophysics · Physics 2011-05-23 A. V. Ivanchik , A. Y. Potekhin , D. A. Varshalovich

The Earth's atmosphere affects ground-based astronomical observations. Scattering, absorption, and radiation processes deteriorate the signal-to-noise ratio of the data received. For scheduling astronomical observations it is, therefore,…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 S. Noll , W. Kausch , M. Barden , A. M. Jones , C. Szyszka , S. Kimeswenger , J. Vinther

Gravitational lens time delays depend on the Hubble constant, the observed image positions, and the surface mass density of the lens in the annulus between the images. Simple time delay lenses like PG1115+080, SBS1520+530, B1600+434,…

Astrophysics · Physics 2008-11-26 C. S. Kochanek

Timescale comparison between optical atomic clocks over ground-to-space and terrestrial free-space laser links will have enormous benefits for fundamental and applied science, from measurements of fundamental constants and searches for dark…

Modeling the optical point spread function (PSF) is particularly challenging for adaptive optics (AO)-assisted observations owing to the its complex shape and spatial variations. We aim to (i) exhaustively demonstrate the accuracy of a…

Instrumentation and Methods for Astrophysics · Physics 2020-11-25 Olivier Beltramo-Martin , Romain Fétick , Benoit Neichel , Thierry Fusco

Large area surveys will dominate the forthcoming decades of astronomy and their success requires characterizing thousands of discoveries through additional observations at higher spatial or spectral resolution, and at complementary cadences…

Instrumentation and Methods for Astrophysics · Physics 2021-11-10 Christoph Baranec , Reed Riddle , Nicholas M. Law

Many applications seek to measure a sample's absorption coefficient spectrum to retrieve the chemical makeup. Many real world samples are optically turbid, causing scattering confounds which many commercial spectrometers cannot address.…

Optics · Physics 2023-01-05 Giles Blaney , Angelo Sassaroli , Sergio Fantini

In ground-based astronomy, Adaptive Optics (AO) is a pivotal technique, engineered to correct wavefront phase distortions and thereby enhance the quality of the observed images. Integral to an AO system is the wavefront sensor (WFS), which…

Instrumentation and Methods for Astrophysics · Physics 2026-05-07 Yutong Wu , Roland Wagner , Ronny Ramlau , Raymond H. Chan

Vapor cell atomic clocks exhibit reduced frequency stability for averaging time between about one hundred and a few thousand seconds. Here we report a study on the impact of the main parameters on the mid-to-long term instability of a…

Atomic Physics · Physics 2016-11-18 Olga Kozlova , Jean-Marie Danet , Stéphane Guérandel , Emeric de Clercq

Motion compensated prediction is central to the efficiency of video compression. Its predictive coding scheme propagates the quantization distortion through the prediction chain and creates a temporal dependency. Prior research typically…

Image and Video Processing · Electrical Eng. & Systems 2021-08-27 Jingning Han , Paul Wilkins , Yaowu Xu , James Bankoski

From natural guide star adaptive optics data taken with the Come-On Plus and with the Starfire Optical Range Generation II instruments in the JHK bands and in the I band respectively, we describe and analyse the point spread function. The…

Astrophysics · Physics 2015-06-24 Eric Tessier

We investigated, through numerical models, the flaring variability that may arise from the rotation of maser clouds of approximately spheroidal geometry, ranging from strongly oblate to strongly prolate examples. Inversion solutions were…

Solar and Stellar Astrophysics · Physics 2019-05-08 M. D. Gray , J. Baggott , J. Westlake , S. Etoka

Plastic scintillation detectors for Time-of-Flight (TOF) measurements are almost essential for event-by-event identification of relativistic rare isotopes. In this work, a pair of plastic scintillation detectors of 50 $\times$ 50 $\times$…

Forecast of optical turbulence and atmospheric parameters relevant for ground-based astronomy is becoming an important goal for telescope planning and AO instruments optimization in several major telescope. Such detailed and accurate…

Instrumentation and Methods for Astrophysics · Physics 2022-10-21 A. Turchi , E. Masciadri , L. Fini
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