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Related papers: Korg: fitting, model atmosphere interpolation, and…

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We have constructed a grid of about 10,000 spherically symmetric and plane-parallel models with the MARCS program, and make it available for public use. Parameter ranges are: Teff=2500 to 8000 K, log g =log(GM/R2)= -1 to 5 (cgs) with…

We performed non-LTE calculations for O I with the plane-parallel model atmospheres for a set of stellar parameters corresponding to A-K type stars. The model atom of Przybilla et al. (2000) was updated using the best theoretical and…

Solar and Stellar Astrophysics · Physics 2013-02-06 T. M. Sitnova , L. I. Mashonkina , T. A. Ryabchikova

We present atmospheric parameters for 51 nearby FG dwarfs uniformly distributed over the -2.60 < [Fe/H] < +0.20 metallicity range that is suitable for the Galactic chemical evolution research. Lines of iron, Fe I and Fe II, were used to…

Solar and Stellar Astrophysics · Physics 2015-08-06 T. Sitnova , G. Zhao , L. Mashonkina , Y. Q. Chen , F. Liu , Yu. Pakhomov , K. Tan , M. Bolte , S. Alexeeva , F. Grupp , J. -R. Shi , H. -W. Zhang

It is generally thought that FRII Radio Galaxies host thin optically thick disks, while FRIs are powered by Advected Dominated Accretion Flows. The sources with an efficient engine are optically classified as High Excitation Radio Galaxies…

High Energy Astrophysical Phenomena · Physics 2021-04-21 Paola Grandi , Eleonora Torresi , Duccio Macconi , Bia Boccardi , Alessandro Capetti

Polarimetry with permille-level precision is essential for future electron-positron linear colliders. Compton polarimeters can reach negligible statistical uncertainties within seconds of measurement time. The dominating systematic…

Instrumentation and Detectors · Physics 2016-02-17 Benedikt Vormwald , Jenny List , Annika Vauth

We demonstrate that phase-matched frequency upconversion of ultrafast laser light can be extended to shorter wavelengths by using longer driving laser wavelengths. Experimentally, we show that the phase-matching cutoff for harmonic…

A standard library of theoretical stellar spectra intended for multiple synthetic photometry applications including spectral evolutionary synthesis is presented. The grid includes M dwarf model spectra, hence complementing the first library…

Astrophysics · Physics 2009-07-28 T. Lejeune , F. Cuisinier , R. Buser

We investigate the imaging and polarization properties of Kerr-MOG black holes surrounded by geometrically thick accretion flows. The MOG parameter $\alpha$ introduces deviations from the Kerr metric, providing a means to test modified…

General Relativity and Quantum Cosmology · Physics 2025-11-18 Xinyu Wang , Huan Ye , Xiao-Xiong Zeng

We build a self-consistent model of a warm scattering corona near an accreting black hole in Kerr geometry, in the regime of slow ($\sim 0.01$ Eddington) mass accretion. An iterative Monte Carlo procedure is developed that incorporates…

High Energy Astrophysical Phenomena · Physics 2026-04-29 Jonathan Zhang , Christopher Thompson

We develop a new interpolation scheme, based on harmonic inpainting, for reconstructing the cosmic microwave background temperature data within the Galaxy mask from the data outside the mask. We find that, for scale-invariant isotropic…

Astrophysics · Physics 2008-11-26 Kaiki Taro Inoue , Paolo Cabella , Eiichiro Komatsu

The determination of chemical composition is crucial for investigating the formation and evolution of star forming galaxies and provides a powerful tool to constrain the effects of galactic winds and accretion from the cosmic web. In this…

Astrophysics of Galaxies · Physics 2018-10-03 Rolf Kudritzki , Miguel A. Urbaneja

Liger is an adaptive optics (AO) fed imager and integral field spectrograph (IFS) designed to take advantage of the Keck All-sky Precision Adaptive-optics (KAPA) upgrade to the Keck I telescope. Liger adapts the design of the InfraRed…

We study the implications of averaging methods with different reference depth scales for 3D hydrodynamical model atmospheres computed with the Stagger-code. The temporally and spatially averaged (hereafter denoted as <3D>) models are…

Solar and Stellar Astrophysics · Physics 2015-06-16 Zazralt Magic , Remo Collet , Wolfgang Hayek , Martin Asplund

We identified a possible origin of the difficulty in abundance analysis of cool luminous stars. We found purely empirically that there is a limit of logW/nu = -4.75 (W: equivalent width, nu: wavenumber) above which the observed lines do not…

Astrophysics · Physics 2009-11-13 Takashi Tsuji

AIMS: We spectroscopically characterize the Galactic Bulge to infer its star formation timescale, compared to the other Galactic components, through the chemical signature on its individual stars. METHODS: We derived iron and oxygen…

Astrophysics · Physics 2010-01-07 M. Zoccali , A. Lecureur , B. Barbuy , V. Hill , A. Renzini , D. Minniti , Y. Momany , A. Gomez , S. Ortolani

Spectroscopic measurements of iron abundances are prone to systematic modelling errors. We present 3D non-LTE calculations across 32 STAGGER-grid models with effective temperatures from 5000 K to 6500 K, surface gravities of 4.0 dex and 4.5…

Solar and Stellar Astrophysics · Physics 2022-12-12 A. M. Amarsi , S. Liljegren , P. E. Nissen

We propose a sparse interpolation construction and a practical coarsening algorithm for the algebraic multigrid (AMG) method, tailored towards H(curl). Building on the generalized AMG framework, we introduce an interior/exterior splitting…

Numerical Analysis · Mathematics 2026-03-02 Taoli Shen , James Brannick , Robert Falgout , Karsten Kahl , Jacob Schroder

KEDR detector has the tagging system (TS) to study the gamma-gamma processes. To determine the two-photon invariant mass, the energies of the scattered at small angles electrons and positrons are measured by the magnetic spectrometer…

Instrumentation and Detectors · Physics 2014-08-28 V. V. Kaminskiy , N. Yu. Muchnoi , V. N. Zhilich

Stark broadened lines of the hydrogen Brackett series are computed for the conditions of stellar atmospheres and circumstellar envelopes. The computation is performed within the Model Microfield Method, which includes the ion dynamic…

Solar and Stellar Astrophysics · Physics 2009-07-06 C. Stehlé , S. Fouquet

A collection of Johnson/Cousins photometry for stars with known [Fe/H] is used to generate color-color relations that include the abundance dependence. Literature temperature and bolometric correction dependences are attached to the color…

Astrophysics · Physics 2011-01-27 G. Worthey , H. -c. Lee