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With the development of terahertz time-domain spectroscopy, methods have been proposed to precisely estimate the thickness, refractive index, and attenuation coefficient of a sample. In this article, we propose a new method to compute these…

Solar irradiance is fundamental data crucial for analyses related to weather and climate. High-precision estimation models are necessary to create areal data for solar irradiance. In this study, we developed a novel estimation model by…

Atmospheric and Oceanic Physics · Physics 2024-07-08 Jun Sasaki , Maki Okada , Kenji Utsunomiya , Koji Yamaguchi

We present an automated procedure for the derivation of atmospheric parameters (Teff, log g, [M/H]) and individual chemical abundances from stellar spectra. The MATrix Inversion for Spectral SythEsis (MATISSE) algorithm determines a basis,…

Astrophysics · Physics 2009-11-11 A. Recio-Blanco , A. Bijaoui , P. de Laverny

Microquasar binary stellar systems emit electromagnetic radiation and high-energy particles over a broad energy spectrum. However, they are so far away that it is hard to observe their details. A simulation offers the link between…

High Energy Astrophysical Phenomena · Physics 2023-11-16 Theodoros Smponias

By the use of Green's second integral identity we determine the field scattered from a two-dimensional randomly rough isotropic or anisotropic Dirichlet or Neumann surface when it is illuminated by a scalar Gaussian beam. The integral…

We introduce a new method for the estimation of the angular parameters [i.e., central directions of arrival (DOAs) and angular spreads] of multiple non-circular and incoherently-distributed (ID) sources and thoroughly analyze its…

Signal Processing · Electrical Eng. & Systems 2019-01-07 Sonia Ben Hassen , Faouzi Bellili , Abdelaziz Samet , Sofiène Affes

We investigate Dicke subradiance of distant quantum sources in free space, i.e., the spatial emission pattern of spontaneously radiating non-interacting multi-level atoms or multi-photon sources, prepared in totally antisymmetric states. We…

Quantum Physics · Physics 2018-03-20 Daniel Bhatti , Raimund Schneider , Steffen Oppel , Joachim von Zanthier

The Cherenkov light produced in air showers largely contributes to the signal observed in ground-based gamma-ray and cosmic-ray observatories. Yet, no description of this phenomenon is available covering both regions of small and large…

High Energy Astrophysical Phenomena · Physics 2021-03-17 Luan Arbeletche , Vitor de Souza

The production and propagation of light antimatter nuclei has been calculated using inclusive antiproton production cross sections from a new data analysis, and coalescence models for the production of composite particles. Particles were…

Astrophysics · Physics 2007-05-23 B. Baret , R. Duperray , G. Boudoul , A. Barrau , Maurin D. Derome , K. Protasov , M. Buenerd

Proper modelling of astronomical receivers is vital: it describes the systematic errors in the raw data, guides the receiver design process, and assists data calibration. In this paper we describe a method of analytically modelling the full…

Instrumentation and Methods for Astrophysics · Physics 2015-06-23 O. G. King , Michael E. Jones , C. Copley , R. J. Davis , J. P. Leahy , J. Leech , S. J. C. Muchovej , T. J. Pearson , Angela C. Taylor

Coadded astronomical images are created by stacking multiple single-exposure images. Because coadded images are smaller in terms of data size than the single-exposure images they summarize, loading and processing them is less…

Instrumentation and Methods for Astrophysics · Physics 2022-11-18 Mallory Wang , Ismael Mendoza , Cheng Wang , Camille Avestruz , Jeffrey Regier

We have worked out simple analytical formulae that accurately approximate the relationship between the position of the source with respect to the lens center and the amplification of the images, hence the lens cross section, for realistic…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 A. Lapi , M. Negrello , J. Gonzalez-Nuevo , Z. -Y. Cai , G. De Zotti , L. Danese

Beamforming is an imaging tool for the investigation of aeroacoustic phenomena and results in high dimensional data that is broken down to spectra by integrating spatial Regions Of Interest. This paper presents two methods that enable the…

Sound · Computer Science 2021-09-29 Armin Goudarzi , Carsten Spehr , Steffen Herbold

The 2 Micron All-Sky Survey (2MASS) will observe over one-million galaxies and extended Galactic sources covering the entire sky at wavelengths between 1 and 2 microns. The survey catalog will have both high completeness and reliability…

Astrophysics · Physics 2009-10-31 T. H. Jarrett , T. Chester , R. Cutri , S. Schneider , M. Skrutskie , J. P. Huchra

The low surface brightness (LSB) regime ($\mu_{g} \gtrsim 26$ mag arcsec$^{-2}$) comprises a vast, mostly unexplored discovery space, from dwarf galaxies to the diffuse interstellar medium. Accessing this regime requires precisely removing…

Astrophysics of Galaxies · Physics 2024-01-24 A. E. Watkins , S. Kaviraj , C. C. Collins , J. H. Knapen , L. S. Kelvin , P. -A. Duc , J. Román , J. C. Mihos

This paper presents a detailed study of the scattering polarization profiles formed under partial frequency redistribution (PRD) in two thermal models of the solar atmosphere. Particular attention is given to understanding the influence of…

Solar and Stellar Astrophysics · Physics 2010-10-12 M. Sampoorna , J. Trujillo Bueno , E. Landi Degl'Innocenti

Ongoing and future surveys with repeat imaging in multiple bands are producing (or will produce) time-spaced measurements of brightness, resulting in the identification of large numbers of variable sources in the sky. A large fraction of…

Instrumentation and Methods for Astrophysics · Physics 2017-11-29 Abhijit Saha , A. Katherina Vivas

There is widespread interest in estimating the fluorescence properties of natural materials in an image. However, the separation between reflected and fluoresced components is difficult, because it is impossible to distinguish reflected and…

Computer Vision and Pattern Recognition · Computer Science 2016-05-16 Henryk Blasinski , Joyce Farrell , Brian Wandell

We present a simple method for calculation of diffraction effects in a beam passing an aperture. It follows the well-known approach of Miyamoto and Wolf, but is simpler and does not lead to singularities. It is thus shown that in the…

Optics · Physics 2020-01-29 Eitam Luz , Er'el Granot , Boris Malomed

An exact model is proposed for a gray, isotropically scattering planetary atmosphere in radiative equilibrium. The slab is illuminated on one side by a collimated beam and is bounded on the other side by an emitting and partially reflecting…

Astrophysics · Physics 2009-11-11 Loic Chevallier , Joachim Pelkowski , Bernard Rutily