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相关论文: Gravity and limb-darkening coefficients for compac…

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Limb-darkening is fundamental in determining transit lightcurve shapes, and is typically modeled by a variety of laws that parametrize the intensity profile of the star that is being transited. Confronted with a transit lightcurve, some…

地球与行星天体物理 · 物理学 2015-05-04 Néstor Espinoza , Andrés Jordán

The characterization of white dwarf atmospheres is crucial for accurately deriving stellar parameters such as effective temperature, mass, and age. We aim to classify the population of white dwarfs up to 500 pc into hydrogen-rich or…

As they evolve, white dwarfs undergo major changes in surface composition, a phenomenon known as spectral evolution. In particular, some stars enter the cooling sequence with helium atmospheres (type DO) but eventually develop hydrogen…

太阳与恒星天体物理 · 物理学 2020-10-07 A. Bédard , P. Bergeron , P. Brassard , G. Fontaine

We have conducted a spectroscopic survey of over 1300 bright (V < 17.5), hydrogen-rich white dwarfs based largely on the last published version of the McCook & Sion catalog. The complete results from our survey, including the spectroscopic…

太阳与恒星天体物理 · 物理学 2015-05-30 Alexandros Gianninas , Pierre Bergeron , Maria Teresa Ruiz

We present a series of systematic abundance measurements for 89 hydrogen atmosphere (DA-type) white dwarfs with temperatures spanning 16000-77000K drawn from the FUSE spectral archive. This is the largest study to date of white dwarfs where…

太阳与恒星天体物理 · 物理学 2015-06-18 M. A. Barstow , J. K. Barstow , S. L. Casewell , J. B. Holberg , I. Hubeny

We present an extended grid of mean three-dimensional (3D) spectra for low-mass, pure-hydrogen atmosphere DA white dwarfs (WDs). We use CO5BOLD radiation-hydrodynamics 3D simulations covering Teff = 6000-11,500 K and logg = 5-6.5 (cgs…

太阳与恒星天体物理 · 物理学 2015-08-26 P. -E. Tremblay , A. Gianninas , M. Kilic , H. -G. Ludwig , M. Steffen , B. Freytag , J. J. Hermes

We report our findings on a spectroscopic survey of seven unresolved DA+DB binary white dwarf candidates. We have discovered extreme spectroscopic variations in one of these candidates, SDSS J084716.21+484220.40. Previous analysis failed to…

太阳与恒星天体物理 · 物理学 2025-01-13 Adam Moss , Mukremin Kilic , Pierre Bergeron , Gracyn Jewett , Warren Brown

We report signal-to-noise ratio SNR ~ 100 optical spectra for four DA white dwarf stars acquired with the GMOS spectrograph of the 8m Gemini north telescope. These stars have 18<g<19 and are around Teff ~ 12000 K, were the hydrogen lines…

天体物理学 · 物理学 2009-11-11 S. O. Kepler , B. G. Castanheira , A. F. M. Costa , D. Koester

We present a detailed spectroscopic analysis of 61 low mass white dwarfs and provide precise atmospheric parameters, masses, and updated binary system parameters based on our new model atmosphere grids and the most recent evolutionary model…

太阳与恒星天体物理 · 物理学 2015-06-22 A. Gianninas , P. Dufour , Mukremin Kilic , Warren R. Brown , P. Bergeron , J. J. Hermes

Our preliminary results from laboratory experiments studying white dwarf (WD) photospheres show a systematic difference between experimental plasma conditions inferred from measured H$\beta$ absorption line profiles versus those from…

太阳与恒星天体物理 · 物理学 2014-10-17 Ross E. Falcon , G. A. Rochau , J. E. Bailey , T. A. Gomez , M. H. Montgomery , D. E. Winget , T. Nagayama

In this work, we investigate the equilibrium structure of white dwarfs within the covariant formulation of symmetric teleparallel $f(Q)$ gravity, in which gravity is described by the nonmetricity scalar $Q$ instead of spacetime curvature.…

广义相对论与量子宇宙学 · 物理学 2026-03-24 Rajasmita Sahoo

White dwarfs with helium-dominated atmospheres comprise approximately 20% of all white dwarfs. Among the open questions are the total masses and the origin of the hydrogen traces observed in a large number and the nature of the deficit of…

太阳与恒星天体物理 · 物理学 2015-11-04 Detlev Koester , S. O. Kepler

In this work we investigate the equilibrium configurations of white dwarfs in a modified gravity theory, na\-mely, $f(R,T)$ gravity, for which $R$ and $T$ stand for the Ricci scalar and trace of the energy-momentum tensor, respectively.…

广义相对论与量子宇宙学 · 物理学 2017-12-20 G. A. Carvalho , R. V. Lobato , P. H. R. S. Moraes , José D. V. Arbañil , R. M. Marinho , E. Otoniel , M. Malheiro

Context.Interpretation of light curves of many types of binary stars requires the inclusion of the (cor)relation between surface brightness and local effective gravity. Until recently, this correlation has always been modeled by a power law…

太阳与恒星天体物理 · 物理学 2015-06-11 Francisco Espinosa Lara , Michel Rieutord

In the framework of our extensive modeling study of the spectral evolution of white dwarfs, we present here a new set of detailed calculations of the transport of residual hydrogen in helium-rich white dwarfs. First, we investigate the…

太阳与恒星天体物理 · 物理学 2023-03-29 A. Bédard , P. Bergeron , P. Brassard

The hydrogen abundances in DBA white dwarfs determined from optical or UV spectra have been reported to differ significantly in some studies. We revisit this problem using our own model atmospheres and synthetic spectra, and present a…

太阳与恒星天体物理 · 物理学 2016-10-28 C. Genest-Beaulieu , P. Bergeron

We examine the properties of damped Lyman-$\alpha$ absorbers (DLAs) emerging from a single set of cosmological initial conditions in two state-of-the-art cosmological hydrodynamic simulations: {\sc Simba} and {\sc Technicolor Dawn}. The…

星系天体物理 · 物理学 2020-01-13 Sultan Hassan , Kristian Finlator , Romeel Davé , Christopher W. Churchill , J. Xavier Prochaska

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

Due to their high photospheric density, cool helium-rich white dwarfs (particularly DZ, DQpec and ultracool) are often poorly described by current atmosphere models. As part of our ongoing efforts to design atmosphere models suitable for…

太阳与恒星天体物理 · 物理学 2016-10-05 Simon Blouin , Patrick Dufour , Piotr M. Kowalski

We present new calculations for the Stark broadening of the hydrogen line profiles in the dense atmospheres of white dwarf stars. Our improved model is based on the unified theory of Stark broadening from Vidal, Cooper & Smith, but it also…

太阳与恒星天体物理 · 物理学 2009-07-22 P. -E. Tremblay , P. Bergeron , J. Dupuis