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Spectral synthesis is basically the decomposition of an observed spectrum in terms of the superposition of a base of simple stellar populations of various ages and metallicities, producing as output the star formation and chemical histories…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Jean Michel Gomes , Polychronis Papaderos

We describe a new code for the deep analysis of stellar fields, designed for Adaptive Optics Nyquist-sampled images with high and low Strehl ratio. The Point Spread Function is extracted directly from the image frame, to take into account…

Astrophysics · Physics 2009-10-31 E. Diolaiti , O. Bendinelli , D. Bonaccini , L. Close , D. Currie , G. Parmeggiani

The formation of stars shapes the structure and evolution of entire galaxies. The rate and efficiency of this process are affected substantially by the density structure of the individual molecular clouds in which stars form. The most…

Astrophysics of Galaxies · Physics 2015-06-19 Jouni Kainulainen , Christoph Federrath , Thomas Henning

We develop a method of analyzing radio frequency spectral line observations to derive data on the temperature, density, velocity, and molecular abundance of the emitting gas. The method incorporates a radiative transfer code with a new…

Astrophysics · Physics 2009-11-10 Eric Keto , George B. Rybicki , Edwin A. Bergin , Rene Plume

Pansharpening, a pivotal task in remote sensing for fusing high-resolution panchromatic and multispectral imagery, has garnered significant research interest. Recent advancements employing diffusion models based on stochastic differential…

Computer Vision and Pattern Recognition · Computer Science 2025-03-20 Zihan Cao , Yu Zhong , Liang-Jian Deng

In this paper we describe the FIT\textit{spec} code, a data mining tool for the automatic fitting of synthetic stellar spectra. The program uses a database of 27\,000 {\sc cmfgen} models of stellar atmospheres arranged in a six-dimensional…

We demonstrate a three-dimensional (3D) optical diffraction tomographic technique with optimal frequency combination (OFC-ODT) for the 3D quantitative phase imaging of unlabeled specimens. Three sets of through-focus intensity images are…

Optics · Physics 2018-03-06 Jiaji Li , Qian Chen Jiasong Sun , Jialin Zhang , Junyi Ding , Chao Zuo

Optical interferometry provides us with a unique opportunity to improve our understanding of stellar structure and evolution. Through direct observation of rotationally distorted photospheres at sub-milliarcsecond scales, we are now able to…

Solar and Stellar Astrophysics · Physics 2012-04-13 Gerard T. van Belle

Spectral efficiency is a key design issue for all wireless communication systems. Orthogonal frequency division multiplexing (OFDM) is a very well-known technique for efficient data transmission over many carriers overlapped in frequency.…

Networking and Internet Architecture · Computer Science 2013-03-28 R. G. Clegg , S. Isam , I. Kanaris , I. Darwazeh

Diffusion tractography is routinely used to study white matter architecture and brain connectivity in vivo. A key step for successful tractography of neuronal tracts is the correct identification of tract directions in each voxel. Here we…

Optical diffraction tomography (ODT) is a tomographic technique that can be used to measure the three-dimensional (3D) refractive index distribution within living cells without the requirement of any marker. In principle, ODT can be…

Quantitative Methods · Quantitative Biology 2018-01-03 Paul Müller , Mirjam Schürmann , Chii J. Chan , Jochen Guck

Spectral synthesis calculations based on three-dimensional stellar atmosphere models are limited by the affordable angular resolution of the radiation field. This hampers an accurate treatment of rotational line broadening. We aim to find a…

Astrophysics · Physics 2007-07-24 Hans-G. Ludwig

Optical properties of dust aggregates are important at various astrophysical environments. To find a reliable approximation method for optical properties of dust aggregates, we calculate the opacity and the asymmetry parameter of dust…

Earth and Planetary Astrophysics · Physics 2018-06-20 Ryo Tazaki , Hidekazu Tanaka

Learning new representations of 3D point clouds is an active research area in 3D vision, as the order-invariant point cloud structure still presents challenges to the design of neural network architectures. Recent works explored learning…

Computer Vision and Pattern Recognition · Computer Science 2022-07-18 Yusuf H. Sahin , Alican Mertan , Gozde Unal

Synthesis performed under non Local Thermodynamic Equilibrium (non-LTE) conditions usually overestimate stellar spectra. An approach widely adopted in the literature to reduce the excess of UV radiation consists of artificially increasing…

Solar and Stellar Astrophysics · Physics 2019-02-20 Serena Criscuoli

Radiative transfer effects need to be taken into account when analysing spectral line observations. When the data are not sufficient for detailed modelling, simpler methods are needed. The escape probability formalism (EPF) is one such…

Instrumentation and Methods for Astrophysics · Physics 2025-04-16 Mika Juvela

How much data is needed to optimally schedule distributed energy resources (DERs)? Does the distribution system operator (DSO) have to know load demands at each bus of the feeder to solve an optimal power flow (OPF)? This work exploits…

Systems and Control · Electrical Eng. & Systems 2025-07-21 Vassilis Kekatos , Ridley Annin , Manish K. Singh , Junjie Qin

Context: Radiative feedback plays a crucial role in the formation of massive stars. The implementation of a fast and accurate description of the proceeding thermodynamics in pre-stellar cores and evolving accretion disks is therefore a main…

Solar and Stellar Astrophysics · Physics 2015-03-13 Rolf Kuiper , Hubert Klahr , Cornelis Dullemond , Wilhelm Kley , Thomas Henning

We address the effects of cosmological surface brightness dimming on observations of faint galaxies by examining the distribution of "unobscured" star formation rate intensities versus redshift. We use the star formation rate intensity…