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相关论文: Uncertainties in (E)UV model atmosphere fluxes

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Spectroscopically determined Li abundances of metal-poor turn-off dwarfs are known to be nearly constant (Spite plateau), but lower than the primordial value expected from the standard cosmological model. However, abundance determination by…

太阳与恒星天体物理 · 物理学 2019-02-06 Yoichi Takeda

Broadband optical and IR spectral energy distributions are determined for spectroscopically confirmed z>2 Lyman break objects in the Hubble Deep Field. These photometric data are compared to spectral synthesis models which take into account…

天体物理学 · 物理学 2007-05-23 Marcin Sawicki , H. K. C. Yee

A new grid of detailed atmosphere model spectra for hot and moderately cool subdwarf stars is presented. High-resolution spectra and synthetic photometry are calculated in the range from 1000{\AA} to 10,000{\AA} using Non-LTE fully…

太阳与恒星天体物理 · 物理学 2021-10-07 Thayse A. Pacheco , Marcos P. Diaz , Ronaldo S. Levenhagen , Paula R. T. Coelho

EUVE, ROSAT, and ASCA observations of the boundary layer emission of nonmagnetic cataclysmic variables (CVs) are reviewed. EUVE spectra reveal that the effective temperature of the soft component of high-Mdot nonmagnetic CVs is kT ~ 10-20…

天体物理学 · 物理学 2008-02-03 Christopher W. Mauche

We present grids of limb-darkening coefficients computed from non-LTE, line-blanketed TLUSTY model atmospheres, covering effective-temperature and surface-gravity ranges of 15--55kK and 4.75 dex (cgs) down to the effective Eddington limit,…

太阳与恒星天体物理 · 物理学 2016-01-27 D. C. Reeve , I. D. Howarth

The reionization optical depth is the most poorly determined of the six $\Lambda$CDM parameters fit to CMB anisotropy data. Instrumental noise and systematics have prevented uncertainties from reaching their cosmic variance limit. At…

宇宙学与河外天体物理 · 物理学 2019-01-09 J. L. Weiland , K. Osumi , G. E. Addison , C. L. Bennett , D. J. Watts , M. Halpern , G. Hinshaw

Turbulent mixing layers (TMLs) are ubiquitous in multiphase gas. They can potentially explain observations of high ions such as O VI, which have significant observed column densities despite short cooling times. Previously, we showed that…

星系天体物理 · 物理学 2021-09-01 Brent Tan , S. Peng Oh

We have used all 20 archival XMM-Newton observations of PKS 2155-304 with simultaneous X-ray and UV/optical data to study its long term flux and spectral variability. We find significant variations, in all bands, on time-scales of years…

高能天体物理现象 · 物理学 2017-12-20 Jai Bhagwan , Alok C. Gupta , I. E. Papadakis , Paul J. Wiita

The evaporation and the chemistry of the atmospheres of warm and hot planets are strongly determined by the high-energy irradiation they receive from their parent stars. This is more crucial among young extra-solar systems, due to the high…

太阳与恒星天体物理 · 物理学 2024-10-23 A. Maggio , I. Pillitteri , C. Argiroffi , D. Locci , S. Benatti , G. Micela

The COS Legacy Archive Spectroscopic SurveY (CLASSY) HST/COS treasury program provides the first high-resolution spectral catalogue of 45 local high-z analogues in the UV (1200-2000\AA) to investigate their stellar and gas properties. We…

We show that a one-component variable-emissivity-spectral-index model (the free-{\alpha} model) provides more physically motivated estimates of dust temperature at the Galactic polar caps than one- or two-component…

星系天体物理 · 物理学 2012-10-24 Z. Liang , D. J. Fixsen , B. Gold

Accurately measuring and modeling the Lyman-$\alpha$ (Ly$\alpha$; $\lambda$1215.67 \AA) emission line from low mass stars is vital for our ability to build predictive high energy stellar spectra, yet interstellar medium (ISM) absorption of…

Panchromatic analysis of galaxy spectral energy distributions, spanning from the ultraviolet to the far-infrared, probes not only the stellar population but also the properties of interstellar dust through its extinction and long-wavelength…

星系天体物理 · 物理学 2023-09-07 G. T. Jones , E. R. Stanway

Lava planets have non-global, condensible atmospheres similar to icy bodies within the solar system. Because they depend on interior dynamics, studying the atmospheres of lava planets can lead to understanding unique geological processes…

地球与行星天体物理 · 物理学 2022-05-25 T. Giang Nguyen , Nicolas B. Cowan , Raymond T. Pierrehumbert , Roxana E. Lupu , John E. Moores

In developing a deeper understanding of the Circumgalactic Medium, one feature that is poorly understood is the nature of the ultraviolet background (UVB) and its impact on observed column densities. A wide array of UVB models have been…

宇宙学与河外天体物理 · 物理学 2025-05-30 Elias Taira , Claire Kopenhafer , Brian W. O'Shea

Context. Acoustic waves in the Sun are affected by the atmospheric layers, but this region is often ignored in forward models due to the increase in computational cost. Aims. The purpose of this work is to take into account the solar…

太阳与恒星天体物理 · 物理学 2025-07-15 Damien Fournier , Janosch Preuss , Thorsten Hohage , Laurent Gizon

In this paper we revise the similarity theory for the stably stratified atmospheric boundary layer (ABL), formulate analytical approximations for the wind velocity and potential temperature profiles over the entire ABL, validate them…

大气与海洋物理 · 物理学 2009-11-13 Sergej Zilitinkevich , Igor Esau

We present work on H alpha spectral line characteristics in PHOENIX stellar model atmospheres and their comparison to microlensing observations. We examine in detail the H alpha equivalent width (EW) and the line shape characteristics for…

天体物理学 · 物理学 2009-11-11 Christine Thurl , Penny D. Sackett , Peter H. Hauschildt

Stratification can cause turbulence spectra to deviate from Kolmogorov's isotropic -5/3 power-law scaling in the universal equilibrium range at high Reynolds numbers. However, a consensus has not been reached with regard to the exact shape…

流体动力学 · 物理学 2018-10-22 Yu Cheng , Qi Li , Stefania Argentini , Chadi Sayde , Pierre Gentine

Tidally locked terrestrial planets around low-mass stars are the prime targets of finding potentially habitable exoplanets. Several atmospheric general circulation models have been employed to simulate their possible climates, however,…

地球与行星天体物理 · 物理学 2020-08-12 Mengyu Wei , Yixiao Zhang , Jun Yang