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相关论文: Hot DA white dwarf model atmosphere calculations: …

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Over the last decade {\it ab initio} modeling of material properties has become widespread in diverse fields of research. It has proved to be a powerful tool for predicting various properties of matter under extreme conditions. We apply…

太阳与恒星天体物理 · 物理学 2015-05-20 Piotr M. Kowalski , Mukremin Kilic

The hot-Jupiter HAT-P-2b has become a prime target for Spitzer Space Telescope observations aimed at understanding the atmospheric response of exoplanets on highly eccentric orbits. Here we present a suite of three-dimensional atmospheric…

地球与行星天体物理 · 物理学 2015-06-22 Nikole K. Lewis , Adam P. Showman , Jonathan J. Fortney , Heather A. Knutson , Mark S. Marley

We explore the idea that the observed variations in the peak luminosities of Type Ia supernovae originate in part from a scatter in metallicity of the main-sequence stars that become white dwarfs. Previous, numerical, studies have not…

天体物理学 · 物理学 2009-11-07 F. X. Timmes , Edward F. Brown , J. W. Truran

In this paper we investigate statistical equilibrium of Ti in the atmospheres of late-type stars. The Ti I/Ti II level populations are computed with available experimental atomic data, except for photoionization and collision induced…

太阳与恒星天体物理 · 物理学 2015-05-20 Maria Bergemann

aims: We determine the solar abundance of phosphorus using co5bold 3D hydrodynamic model atmospheres. method: High resolution, high signal-to-noise solar spectra of the PI lines of Multiplet 1 at 1051-1068 nm are compared to line formation…

天体物理学 · 物理学 2009-11-13 Elisabetta Caffau , Matthias Steffen , Luca Sbordone , Hans-G. Ludwig , Piercarlo Bonifacio

We utilize state-of-the-art 3D hydrodynamical and classical 1D stellar model atmospheres to study the influence of convection on the formation properties of various atomic and molecular spectral lines in the atmospheres of four red giant…

太阳与恒星天体物理 · 物理学 2013-10-30 V. Dobrovolskas , A. Kučinskas , M. Steffen , H. -G. Ludwig , D. Prakapavičius , J. Klevas , E. Caffau , P. Bonifacio

Dense, He-rich atmospheres of cool white dwarfs represent a challenge to the modeling. This is because these atmospheres are constituted of a dense fluid in which strong multi-atomic interactions determine their physics and chemistry.…

太阳与恒星天体物理 · 物理学 2016-10-25 Piotr M. Kowalski , Simon Blouin , Patrick Dufour

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

Optical observations of nova V1974 Cygni (Cygni 1992), spanning a 4 year period, have been used to study its spectroscopic evolution. The data cover a wavelength range from $\sim 3200 - 8000$ \AA and follows the nebular evolutionary phase…

天体物理学 · 物理学 2009-10-31 A. Moro-Martin , P. M. Garnavich , A. Noriega-Crespo

Heavy-metal hot subdwarfs (sdB and sdO) represent a small group of stars with unusually high concentrations of trans-iron elements in their atmospheres, having abundances ~ 10000 times solar. One example is LS IV-14$^{\circ}$ 116, where a…

原子物理 · 物理学 2020-07-01 L. Fernández-Menchero , C. S. Jeffery , C. A. Ramsbottom , C. P. Ballance

Abundances of lithium, carbon, and oxygen have been derived using spectral synthesis for a sample of 249 bright F, G, and K Northern Hemisphere dwarf stars from the high-resolution spectra acquired with the VUES spectrograph at the Moletai…

Spectral modelling of kilonovae (KNe) require large amounts of collisional excitation and photoionization atomic data for lowly ionised (neutral, singly and doubly ionised) species of heavy elements. Much of the data currently used is…

高能天体物理现象 · 物理学 2026-02-25 Leo P. Mulholland , Catherine A. Ramsbottom , Connor P. Ballance , Albert Sneppen , Stuart A. Sim

We present some early results from a study of five hot DA white dwarf stars, based on spectra obtained using STIS. All show multiple components in one or more of the strong resonance absorption lines typically associated with the stellar…

天体物理学 · 物理学 2007-05-23 N. P. Bannister , M. A. Barstow , J. B. Holberg , F. C. Bruhweiler

We construct partially ionized hydrogen atmosphere models for magnetized neutron stars in radiative equilibrium with surface fields B=10^12-5 \times 10^14 G and effective temperatures T_eff \sim a few \times 10^5-10^6 K. These models are…

天体物理学 · 物理学 2009-11-10 Wynn C. G. Ho , Dong Lai , Alexander Y. Potekhin , Gilles Chabrier

We construct time-dependent one-dimensional (vertically averaged) models of accretion disks produced by the tidal disruption of a white dwarf (WD) by a binary neutron star (NS) companion. Nuclear reactions in the disk midplane burn the WD…

高能天体物理现象 · 物理学 2016-09-16 Ben Margalit , Brian D. Metzger

Coalescence of binary neutron star give rise to electromagnetic emission, kilonova, powered by radioactive decays of r-process nuclei. Observations of kilonova associated with GW170817 provided unique opportunity to study the heavy element…

太阳与恒星天体物理 · 物理学 2019-02-13 Gediminas Gaigalas , Daiji Kato , Pavel Rynkun , Laima Radziute , Masaomi Tanaka

Recently, white dwarf stars have found a new use in the fundamental physics community. Many prospective theories of the fundamental interactions of Nature allow traditional constants, like the fine structure constant $\alpha$, to vary in…

太阳与恒星天体物理 · 物理学 2014-10-14 S. P. Preval , M. A. Barstow , J. B. Holberg , J. D. Barrow , J. C. Berengut , J. K. Webb , D. Dougan , J. Hu

Observations of planetary material polluting the atmospheres of white dwarfs are an important probe of the bulk composition of exoplanetary material. Medium- and high-resolution optical and ultraviolet spectroscopy of seven white dwarfs…

地球与行星天体物理 · 物理学 2023-11-27 L. K. Rogers , A. Bonsor , S. Xu , P. Dufour , B. L. Klein , A. Buchan , S. Hodgkin , F. Hardy , M. Kissler-Patig , C. Melis , A. J. Weinberger , B. Zuckerman

This paper presents the set of plane-parallel model atmosphere equations for a very hot neutron star (X-ray burst source). The model equations assume both hydrostatic and radiative equilibrium, and the equation of state of an ideal gas in…

天体物理学 · 物理学 2009-11-10 A. Majczyna , J. Madej , P. C. Joss , A. Rozanska

We have compared Monte Carlo photoionization models of H II regions with a uniform density distribution with models with the same central stars and chemical compositions but with 3-D hierarchical clumps. We compare the abundances of He, N,…

天体物理学 · 物理学 2009-11-10 John S. Mathis , Kenneth Wood