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相关论文: Estimating Atmospheric Parameters of DA White Dwar…

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We design a convolutional neural network (CNN) incorporating channel attention and spatial attention mechanisms to predict atmospheric parameters of hot subdwarfs. The experimental dataset comprises spectra at nine distinct signal-to-noise…

太阳与恒星天体物理 · 物理学 2026-01-06 Zhenxin Lei , Yangyang Dong , Bokai Kou , Mengqi Feng , Ke Hu , Yude Bu , Jingkun Zhao

We present techniques for the estimation of stellar atmospheric parameters (Teff,logg,[Fe/H]) for stars from the SDSS/SEGUE survey. The atmospheric parameters are derived from the observed medium-resolution (R=2000) stellar spectra using…

The measurement of atmospheric parameters is fundamental for scientific research using stellar spectra. The Chinese Space Station Telescope (CSST), scheduled to be launched in 2024, will provide researchers with hundreds of millions of…

太阳与恒星天体物理 · 物理学 2024-08-21 JiaRui Rao , HaiLiang Chen , JianPing Xiong , LuQian Wang , YanJun Guo , JiaJia Li , Chao Liu , ZhanWen Han , XueFei Chen

We present a detailed calculation of model atmospheres for DA white dwarfs. Our atmosphere code solves the atmosphere structure in local thermodynamic equilibrium with a standard partial linearization technique, which takes into account the…

天体物理学 · 物理学 2015-06-24 R. D. Rohrmann

We explore the application of artificial neural networks (ANNs) for the estimation of atmospheric parameters (Teff, logg, and [Fe/H]) for Galactic F- and G-type stars. The ANNs are fed with medium-resolution (~ 1-2 A) non flux-calibrated…

Hot DA white dwarfs have fully radiative pure hydrogen atmospheres that are the least complicated to model. Pulsationally stable, they are fully characterized by their effective temperature Teff, and surface gravity log g, which can be…

The surface gravities of cool (Teff < 13,000 K) hydrogen-atmosphere DA white dwarfs, determined from spectroscopic analyses, are found to be significantly higher than the canonical value of log g ~ 8 expected for these stars. It was…

太阳与恒星天体物理 · 物理学 2015-05-28 P. -E. Tremblay , H. -G. Ludwig , M. Steffen , P. Bergeron , B. Freytag

We present initial results from a program aimed at establishing a network of hot DA white dwarfs to serve as spectrophotometric standards for present and future wide-field surveys. These stars span the equatorial zone and are faint enough…

We present the first grid of mean three-dimensional (3D) spectra for pure-hydrogen (DA) white dwarfs based on 3D model atmospheres. We use CO5BOLD radiation-hydrodynamics 3D simulations instead of the mixing-length theory for the treatment…

太阳与恒星天体物理 · 物理学 2015-06-17 P. -E. Tremblay , H. -G. Ludwig , M. Steffen , B. Freytag

A fundamental challenge for wide-field imaging surveys is obtaining follow-up spectroscopic observations: there are > $10^9$ photometrically cataloged sources, yet modern spectroscopic surveys are limited to ~few x $10^6$ targets. As we…

太阳与恒星天体物理 · 物理学 2015-06-23 A. A. Miller , J. S. Bloom , J. W. Richards , Y. S. Lee , D. L. Starr , N. R. Butler , S. Tokarz , N. Smith , J. A. Eisner

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

An initial assessment is made of white dwarf and hot subdwarf stars observed in the Sloan Digital Sky Survey. In a small area of sky (190 square degrees), observed much like the full survey will be, 269 white dwarfs and 56 hot subdwarfs are…

The accurate flux calibration of observational data is vital for astrophysics and cosmology because absolute flux uncertainties of stellar standards propagate into scientific results. With the ever higher precision achieved by telescopic…

White dwarf photospheric parameters are usually obtained by means of spectroscopic or photometric analysis. These results are not always consistent with each other, with the published values often including just the statistical…

We present an improved spectroscopic and photometric analysis of hydrogen-line DA white dwarfs from the Sloan Digital Sky Survey Data Release 4 based on model atmospheres that include improved Stark broadening profiles with non-ideal gas…

太阳与恒星天体物理 · 物理学 2015-05-27 P. -E. Tremblay , P. Bergeron , A. Gianninas

We present atmospheric parameters for a large sample of DA white dwarfs that are known to be photometrically constant. For each star, we determine the effective temperature and surface gravity by comparing high signal-to-noise ratio optical…

天体物理学 · 物理学 2009-11-13 A. Gianninas , P. Bergeron , G. Fontaine

White dwarf and pre-white dwarf atmospheres are one of the best examples for the application of Stark broadening research results in astrophysics, due to plasma conditions very favorable for this line broadening mechanism. For example in…

太阳与恒星天体物理 · 物理学 2018-03-14 Milan S. Dimitrijevic , Andjelka Kovacevic , Zoran Simic , Sylvie Sahal-Brechot

The spectroscopic features of white dwarfs are formed in the thin upper layer of their stellar photosphere. These features carry information about the white dwarf's surface temperature, surface gravity, and chemical composition (hereafter…

太阳与恒星天体物理 · 物理学 2020-09-09 Vedant Chandra , Hsiang-Chih Hwang , Nadia L. Zakamska , Tamás Budavári

A scheme for estimating atmospheric parameters T$_{eff}$, log$~g$, and [Fe/H] is proposed on the basis of Least Absolute Shrinkage and Selection Operator (LASSO) algorithm and Haar wavelet. The proposed scheme consists of three processes. A…

太阳与恒星天体物理 · 物理学 2015-08-04 Yu Lu , Xiangru Li

We present fundamental atmospheric parameters (Teff and log g) and metallicities ([M/H]) for 507,513 M dwarf stars using low-resolution spectra (R~1800) from LAMOST DR10. By employing Cycle-StarNet, an innovative domain adaptation approach,…

太阳与恒星天体物理 · 物理学 2025-02-05 Shuo Zhang , Hua-Wei Zhang , Yuan-Sen Ting , Rui Wang , Teaghan O'Briain , Hugh R. A. Jones , Derek Homeier , A-Li Luo
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