VALD-2 - The New Vienna Atomic Line Database

Kupka, F.; Ryabchikova, T. A.; Piskunov, Nikolai; Stempels, H. C.; Weiss, W. W.

doi:10.1515/astro-2000-0420

Cited by 412 publications

(447 citation statements)

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“…The Fe lines used were taken from VALD linelists (Kupka et al 2000). We first calculated in MOOG the theoretical equivalent width (EW) of all available Fe I and Fe II in a wavelength range between 400 and 700 nm for a grid, centred on the seismic parameters found (Table 1).…”

Section: Fundamental Parametersmentioning

confidence: 99%

Pulsating red giant stars in eccentric binary systems discovered fromKeplerspace-based photometry

Beck

Hambleton

Vos

et al. 2014

A&A

132

151

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Context. The unparalleled photometric data obtained by NASA's Kepler Space Telescope has led to improved understanding of red giant stars and binary stars. Seismology allows us to constrain the properties of red giants. In addition to eclipsing binaries, eccentric non-eclipsing binaries that exhibit ellipsoidal modulations have been detected with Kepler. Aims. We aim to study the properties of eccentric binary systems containing a red giant star and to derive the parameters of the primary giant component. Methods. We applied asteroseismic techniques to determine the masses and radii of the primary component of each system. For a selected target, light and radial velocity curve modelling techniques were applied to extract the parameters of the system and its primary component. Stellar evolution and its effects on the evolution of the binary system were studied from theoretical models. Results. The paper presents the asteroseismic analysis of 18 pulsating red giants in eccentric binary systems, for which masses and radii were constrained. The orbital periods of these systems range from 20 to 440 days. The results of our ongoing radial velocity monitoring programme with the Hermes spectrograph reveal an eccentricity range of e = 0.2 to 0.76. As a case study we present a detailed analysis of KIC 5006817, whose rich oscillation spectrum allows for detailed seismic analysis. From seismology we constrain the rotational period of the envelope to be at least 165 d, which is roughly twice the orbital period. The stellar core rotates 13 times faster than the surface. From the spectrum and radial velocities we expect that the Doppler beaming signal should have a maximum amplitude of 300 ppm in the light curve. Fixing the mass and radius to the asteroseismically determined values, we find from our binary modelling a value of the gravity darkening exponent that is significantly larger than expected. Through binary modelling, we determine the mass of the secondary component to be 0.29 ± 0.03 M . Conclusions. For KIC 5006817 we exclude pseudo-synchronous rotation of the red giant with the orbit. The comparison of the results from seismology and modelling of the light curve shows a possible alignment of the rotational and orbital axis at the 2σ level. Red giant eccentric systems could be progenitors of cataclysmic variables and hot subdwarf B stars.

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Section: Fundamental Parametersmentioning

confidence: 99%

Pulsating red giant stars in eccentric binary systems discovered fromKeplerspace-based photometry

Beck

Hambleton

Vos

et al. 2014

A&A

132

151

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“…To produce the LSD profiles we generated a line list appropriate for a M3.5V star (T eff = 3100K and logg = 4.88) from the Vienna Atomic Line Database (VALD3; Kupka et al 2000), adopting a detection limit of 0.1. The normalized line depths were scaled by a fit to the continuum of a M3.5V template star so each line's relative depth was correct for use with the continuum subtracted spectra.…”

Section: Least Squares Deconvolutionmentioning

confidence: 99%

The crowded magnetosphere of the post-common-envelope binary QS Virginis

Parsons

Hill

Marsh

et al. 2016

Mon. Not. R. Astron. Soc.

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We present high speed photometry and high resolution spectroscopy of the eclipsing post common envelope binary QS Virginis (QS Vir). Our UVES spectra span multiple orbits over more than a year and reveal the presence of several large prominences passing in front of both the M star and its white dwarf companion, allowing us to triangulate their positions. Despite showing small variations on a timescale of days, they persist for more than a year and may last decades. One large prominence extends almost three stellar radii from the M star. Roche tomography reveals that the M star is heavily spotted and that these spots are longlived and in relatively fixed locations, preferentially found on the hemisphere facing the white dwarf. We also determine precise binary and physical parameters for the system. We find that the 14, 220 ± 350 K white dwarf is relatively massive, 0.782 ± 0.013M ⊙ , and has a radius of 0.01068 ± 0.00007R ⊙ , consistent with evolutionary models. The tidally distorted M star has a mass of 0.382 ± 0.006M ⊙ and a radius of 0.381 ± 0.003R ⊙ , also consistent with evolutionary models. We find that the magnesium absorption line from the white dwarf is broader than expected. This could be due to rotation (implying a spin period of only ∼700 seconds), or due to a weak (∼100kG) magnetic field, we favour the latter interpretation. Since the M star's radius is still within its Roche lobe and there is no evidence that its over-inflated we conclude that QS Vir is most likely a pre-cataclysmic binary just about to become semi-detached.

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“…Atomic and molecular data were taken, respectively, from the Vienna Atomic Line Database -VALD (Kupka et al 1999(Kupka et al , 2000Piskunov et al 1995;Ryabchikova et al 1997) and from Kurucz (1992). In addition to C 2 , the spectral regions studied also include MgH molecular features that may contribute to the continuum formation.…”

Section: Carbon Abundance From Spectral Synthesismentioning

confidence: 99%

Accurate and homogeneous abundance patterns in solar-type stars of the solar neighbourhood: a chemo-chronological analysis

Silva

Mello

Milone

et al. 2012

A&A

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Aims. We report the derivation of abundances of C, Na, Mg, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, Ce, Nd, and Sm in a sample of 25 solar-type stars of the solar neighbourhood, correlating the abundances with the stellar ages, kinematics, and orbital parameters. Methods. The spectroscopic analysis, based on data of high resolution and high signal-to-noise ratio, was differential to the Sun and applied to atomic line equivalent widths supplemented by the spectral synthesis of C and C 2 features. We also performed a statistical study by using the method of tree clustering analysis, searching for groups of stars sharing similar elemental abundance patterns. We derived the stellar parameters from various criteria, with average errors of 30 K, 0.13 dex, and 0.05 dex, respectively, for T eff , log g, and [Fe/H]. The average error of the [X/Fe] abundance ratios is 0.06 dex. Ages were derived from theoretical HR diagrams and membership of the stars in known kinematical moving groups.

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VALD-2 - The New Vienna Atomic Line Database

Cited by 412 publications

References 0 publications

Pulsating red giant stars in eccentric binary systems discovered fromKeplerspace-based photometry

Pulsating red giant stars in eccentric binary systems discovered fromKeplerspace-based photometry

The crowded magnetosphere of the post-common-envelope binary QS Virginis

Accurate and homogeneous abundance patterns in solar-type stars of the solar neighbourhood: a chemo-chronological analysis

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