| 1. |
- Dubernet, M. L., et al.
(författare)
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The virtual atomic and molecular data centre (VAMDC) consortium
- 2016
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Ingår i: Journal of Physics B. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 49:7
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Tidskriftsartikel (refereegranskat)abstract
- The Virtual Atomic and Molecular Data Centre (VAMDC) Consortium is a worldwide consortium which federates atomic and molecular databases through an e-science infrastructure and an organisation to support this activity. About 90% of the inter-connected databases handle data that are used for the interpretation of astronomical spectra and for modelling in many fields of astrophysics. Recently the VAMDC Consortium has connected databases from the radiation damage and the plasma communities, as well as promoting the publication of data from Indian institutes. This paper describes how the VAMDC Consortium is organised for the optimal distribution of atomic and molecular data for scientific research. It is noted that the VAMDC Consortium strongly advocates that authors of research papers using data cite the original experimental and theoretical papers as well as the relevant databases.
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| 2. |
- Boyarchuk, A. A., et al.
(författare)
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Scientific problems addressed by the Spektr-UV space project (world space Observatory-Ultraviolet)
- 2016
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Ingår i: Astronomy reports (Print). - 1063-7729 .- 1562-6881. ; 60:1, s. 1-42
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Tidskriftsartikel (refereegranskat)abstract
- The article presents a review of scientific problems and methods of ultraviolet astronomy, focusing on perspective scientific problems (directions) whose solution requires UV space observatories. These include reionization and the history of star formation in the Universe, searches for dark baryonic matter, physical and chemical processes in the interstellar medium and protoplanetary disks, the physics of accretion and outflows in astrophysical objects, from Active Galactic Nuclei to close binary stars, stellar activity (for both low-mass and high-mass stars), and processes occurring in the atmospheres of both planets in the solar system and exoplanets. Technological progress in UV astronomy achieved in recent years is also considered. The well advanced, international, Russian-led Spektr-UV (World Space Observatory-Ultraviolet) project is described in more detail. This project is directed at creating a major space observatory operational in the ultraviolet (115-310 nm). This observatory will provide an effective, and possibly the only, powerful means of observing in this spectral range over the next ten years, and will be an powerful tool for resolving many topical scientific problems.
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| 3. |
- Dubernet, M. L., et al.
(författare)
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Virtual atomic and molecular data centre
- 2010
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Ingår i: Journal of Quantitative Spectroscopy and Radiative Transfer. - 0022-4073 .- 1879-1352. ; 111:15, s. 2151-2159
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Tidskriftsartikel (refereegranskat)abstract
- The Virtual Atomic and Molecular Data Centre (VAMDC, http://www.vamdc.eu) is a European Union funded collaboration between groups involved in the generation, evaluation, and use of atomic and molecular data. VAMDC aims to build a secure, documented, flexible and interoperable e-science environment-based interface to existing atomic and molecular data. The project will cover establishing the core consortium, the development and deployment of the infrastructure and the development of interfaces to the existing atomic and molecular databases. It will also provide a forum for training potential users and dissemination of expertise worldwide. This review describes the scope of the VAMDC project; it provides a survey of the atomic and molecular data sets that will be included plus a discussion of how they will be integrated. Some applications of these data are also discussed.
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| 4. |
- Zwintz, K., et al.
(författare)
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beta Cas : The first ffi Scuti star with a dynamo magnetic field
- 2020
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Ingår i: Astronomy and Astrophysics. - : EDP SCIENCES S A. - 0004-6361 .- 1432-0746. ; 643
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Tidskriftsartikel (refereegranskat)abstract
- Context. F-type stars are characterised by several physical processes such as different pulsation mechanisms, rotation, convection, diffusion, and magnetic fields. The rapidly rotating delta Scuti star beta Cas can be considered as a benchmark star to study the interaction of several of these effects.Aims. We investigate the pulsational and magnetic field properties of beta Cas. We also determine the star's apparent fundamental parameters and chemical abundances.Methods. Based on photometric time series obtained from three different space missions (BRITE-Constellation, SMEI, and TESS), we conduct a frequency analysis and investigate the stability of the pulsation amplitudes over four years of observations. We investigate the presence of a magnetic field and its properties using spectropolarimetric observations taken with the Narval instrument by applying the least-squares deconvolution and Zeeman-Doppler imaging techniques.Results. The star beta Cas shows only three independent p-mode frequencies down to the few ppm-level; its highest amplitude frequency is suggested to be an n=3, l=2, m=0 mode. Its magnetic field structure is quite complex and almost certainly of a dynamo origin. The atmosphere of beta Cas is slightly deficient in iron peak elements and slightly overabundant in C, O, and heavier elements.Conclusions. Atypically for delta Scuti stars, we can only detect three pulsation modes down to exceptionally low noise levels for beta Cas. The star is also one of very few delta Scuti pulsators known to date to show a measurable magnetic field and the first delta Scuti star with a dynamo magnetic field. These characteristics make beta Cas an interesting target for future studies of dynamo processes in the thin convective envelopes of F-type stars, the transition region between fossil and dynamo fields, and the interaction between pulsations and magnetic field.
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| 5. |
- Ryabchikova, T., et al.
(författare)
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Pulsation in the atmosphere of the roAp star HD 24712 : I. Spectroscopic observations and radial velocity measurements
- 2007
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 462:3, s. 1103-1112
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Tidskriftsartikel (refereegranskat)abstract
- Aims.We have investigated the structure of the pulsating atmosphere of one of the best studied rapidly oscillating Ap stars, HD 24712.Methods.For this purpose we analyzed spectra collected during 2001-2004. An extensive data set was obtained in 2004 simultaneously with the photometry of the Canadian MOST mini-satellite. This allows us to connect directly atmospheric dynamics observed as radial velocity variations with light variations seen in photometry. Results.We directly derived for the first time and for different chemical elements, respectively ions, phase shifts between photometric and radial velocity pulsation maxima indicating, as we suggest, different line formation depths in the atmosphere. This allowed us to estimate for the first time the propagation velocity of a pulsation wave in the outer stellar atmosphere of a roAp star to be slightly lower than the sound speed. We confirm large pulsation amplitudes (150-400 m s-1) for REE lines and the H core, while spectral lines of the other elements (Mg, Si, Ca, and Fe-peak elements) have nearly constant velocities. We did not find different pulsation amplitudes and phases for the lines of rare-earth elements before and after the Balmer jump, which supports the hypothesis of REE concentration in the upper atmosphere above the hydrogen line-forming layers. We also discuss radial velocity amplitudes and phases measured for individual spectral lines as tools for a 3D tomography of the atmosphere of HD 24712.
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| 6. |
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| 7. |
- Kochukhov, Oleg, et al.
(författare)
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V772 Cas : an ellipsoidal HgMn star in an eclipsing binary
- 2021
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press. - 0035-8711 .- 1365-2966. ; 500:2, s. 2577-2589
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Tidskriftsartikel (refereegranskat)abstract
- The late B-type star V772 Cas (HD10260) was previously suspected to be a rare example of a magnetic chemically peculiar star in an eclipsing binary system. Photometric observations of this star obtained by the TESS satellite show clear eclipses with a period of 5.0137 d accompanied by a significant out-of-eclipse variation with the same period. High-resolution spectroscopy reveals V772 Cas to be an SB1 system, with the primary component rotating about a factor two slower than the orbital period and showing chemical peculiarities typical of non-magnetic HgMn chemically peculiar stars. This is only the third eclipsing HgMn star known and, owing to its brightness, is one of the very few eclipsing binaries with chemically peculiar components accessible to detailed follow-up studies. Taking advantage of the photometric and spectroscopic observations available for V772 Cas, we performed modelling of this system with the PHOEBE code. This analysis provided fundamental parameters of the components and demonstrated that the out-of-eclipse brightness variation is explained by the ellipsoidal shape of the evolved, asynchronously rotating primary. This is the first HgMn star for which such variability has been definitively identified.
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| 8. |
- Nesvacil, N., et al.
(författare)
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A self-consistent chemically stratified atmosphere model for the roAp star 10 Aquilae
- 2013
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 552, s. A28-
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Tidskriftsartikel (refereegranskat)abstract
- Context. Chemically peculiar A-type (Ap) stars are a subgroup of the CP2 stars that exhibit anomalous overabundances of numerous elements, e.g. Fe, Cr, Sr, and rare earth elements. The pulsating subgroup of Ap stars, the roAp stars, present ideal laboratories to observe and model pulsational signatures, as well as the interplay of the pulsations with strong magnetic fields and vertical abundance gradients. Aims. Based on high-resolution spectroscopic observations and observed stellar energy distributions, we construct a self-consistent model atmosphere for the roAp star 10 Aquilae (HD 176232). It accounts for modulations of the temperature-pressure structure caused by vertical abundance gradients. We demonstrate that such an analysis can be used to determine precisely the fundamental atmospheric parameters required for pulsation modelling. Methods. Average abundances were derived for 56 species. For Mg, Si, Ca, Cr, Fe, Co, Sr, Pr, and Nd, vertical stratification profiles were empirically derived using the DDAFIT minimisation routine together with the magnetic spectrum synthesis code SYNTHMAG. Model atmospheres were computed with the LLMODELS code, which accounts for the individual abundances and stratification of chemical elements. Results. For the final model atmosphere, T-eff = 7550 K and log (g) = 3.8 were adopted. While Mg, Si, Co, and Cr exhibit steep abundance gradients, Ca, Fe, and Sr showed much wider abundance gradients between log tau(5000) = -1.5 and 0.5. Elements Mg and Co were found to be the least stratified, while Ca and Sr showed strong depth variations in abundance of up to approximate to 6 dex.
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| 9. |
- Nesvacil, N., et al.
(författare)
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Multi-element Doppler imaging of the CP2 star HD 3980
- 2012
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 537
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Tidskriftsartikel (refereegranskat)abstract
- Context. In atmospheres of magnetic main-sequence stars, the diffusion of chemical elements leads to a number of observed anomalies, such as abundance spots across the stellar surface. Aims. The aim of this study was to derive a detailed picture of the surface abundance distribution of the magnetic chemically peculiar star HD 3980. Methods. Based on high-resolution, phase-resolved spectroscopic observations of the magnetic A-type star HD 3980, the inhomogeneous surface distribution of 13 chemical elements (Li, O, Si, Ca, Cr, Mn, Fe, La, Ce, Pr, Nd, Eu, and Gd) has been reconstructed. The INVERS12 code was used to invert the rotational variability in line profiles to elemental surface distributions. Results. Assuming a centered, dominantly dipolar magnetic field configuration, we find that Li, O, Mg, Pr, and Nd are mainly concentrated in the area of the magnetic poles and depleted in the regions around the magnetic equator. The high abundance spots of Si, La, Ce, Eu, and Gd are located between the magnetic poles and the magnetic equator. Except for La, which is clearly depleted in the area of the magnetic poles, no obvious correlation with the magnetic field has been found for these elements otherwise. Ca, Cr, and Fe appear enhanced along the rotational equator and the area around the magnetic poles. The intersection between the magnetic and the rotational equator constitutes an exception, especially for Ca and Cr, which are depleted in that region. Conclusions. No obvious correlation between the theoretically predicted abundance patterns and those determined in this study could be found. This can be attributed to a lack of up-to-date theoretical models, especially for rare earth elements.
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| 10. |
- Ryabchikova, T., et al.
(författare)
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Accuracy of atmospheric parameters of FGK dwarfs determined by spectrum fitting
- 2016
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 456:2, s. 1221-1234
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Tidskriftsartikel (refereegranskat)abstract
- We performed extensive tests of the accuracy of atmospheric parameter determination for FGK stars based on the spectrum fitting procedure SpectroscopyMade Easy (SME). Our stellar sample consists of 13 objects, including the Sun, in the temperature range 5000-6600K and metallicity range -1.4-+0.4. The analysed stars have the advantage of having parameters derived by interferometry. For each star, we use spectra obtained with different spectrographs and different signal-to-noise ratios (S/N). For the fitting, we adopted three different sets of constraints and test how the derived parameters depend upon the spectral regions (masks) used in SME. We developed and implemented in SME a new method for estimating uncertainties in the resulting parameters based on fitting residuals, partial derivatives, and data uncertainties. For stars in the 5700-6600K range, the best agreement with the effective temperatures derived by interferometry is achieved when spectrum fitting includes the Ha and H beta lines, while for cooler stars the choice of the mask does not affect the results. The derived atmospheric parameters do not strongly depend on spectral resolution and S/N of the observations, while the uncertainties in temperature and surface gravity increase with increasing effective temperature, with minima at 50K in T-eff and 0.1 dex in log g, for spectra with S/N=150-200. A non-local thermodynamic equilibrium (NLTE) analysis of the Ti I/Ti II and Fe I/Fe II ionization equilibria and abundances determined from the atomic CI (NLTE) and molecular CH species supports the parameters we derived with SME by fitting the observed spectra including the hydrogen lines.
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| 11. |
- Semenko, E. A., et al.
(författare)
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Abundance analysis and searching for nonradial pulsations in the atmosphere of the chemically peculiar star HD 115708
- 2008
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Ingår i: Astronomy letters. - 1063-7737 .- 1562-6873. ; 34:6, s. 413-422
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Tidskriftsartikel (refereegranskat)abstract
- We present the results of our abundance analysis for the magnetic chemically peculiar star HD 115708 based on high-resolution spectra. The atmospheric chemical composition of HD 115708 (T (eff) = 7550 K) is shown to be typical of cool Ap stars with a significant ionization disequilibrium for the first and second rare earth ions, which is commonly observed in the atmospheres of pulsating Ap (roAp) stars. Our study of the vertical distribution of elements has shown that Mg, Ca, Cr, and Fe concentrate in deeper atmospheric layers, with their abundances decreasing sharply in the upper layers. The jumps in abundance are 1.5-3 orders of magnitude. Silicon is distributed in depth almost uniformly in the atmosphere of HD 115708. The derived empirical Cr and Fe distributions agree qualitatively with the results of diffusion calculations. Since the atmospheric chemical peculiarities in HD 115708 correspond to roAp stars, we have performed a spectroscopic monitoring to find nonradial pulsations. We have been able to determine only an upper limit for the amplitude of the possible radial velocity pulsations, similar to 100 m s(-1), due to the insufficient temporal resolution and instability of the main stellar spectrograph (MSS) of the 6-m telescope.
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| 12. |
- Titarenko, A. P., et al.
(författare)
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Chemical composition and evolutionary status of the Ap star HD 138633
- 2013
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Ingår i: Astronomy letters. - 1063-7737 .- 1562-6873. ; 39:5, s. 347-356
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Tidskriftsartikel (refereegranskat)abstract
- We present the results of our study of the atmospheric chemical composition and evolutionary status for the chemically peculiar Ap star HD 138633. In contrast to ordinary Ap stars that exhibit strong lines of rare-earth elements in their spectra, these elements are represented very poorly in the spectrum of HD 138633. The magnetic field is estimated to be less than 700 G, which is also atypical of peculiar Ap stars. We have detected a stratification of such elements as Fe, Si, Ca, and Y in the atmosphere of HD 138633 whose pattern agrees qualitatively with the predictions of the theory of diffusive separation of elements under the joint action of gravity and radiation pressure forces. The nonuniform distribution obtained by assuming a stepwise distribution of elements in depth agrees qualitatively with the stratification distribution for beta CrB. The search for pulsations points to the possible existence of lowamplitude pulsations with a period of about 17 min.
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| 13. |
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| 14. |
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| 15. |
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| 16. |
- Iyudin, Anatoli F., et al.
(författare)
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Search for broad absorption lines in spectra of stars in the field of supernova remnant RX J0852.0-4622 (Vela Jr.)
- 2010
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 519:9, s. A86-
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Tidskriftsartikel (refereegranskat)abstract
- Aims. Supernova remnant (SNR) RX J0852.0-4622 is one of the youngest and is most likely the closest among known Galactic SNRs. It was detected in X-rays, the (44)Ti gamma-line, and radio. We obtain and analyze medium-resolution spectra of 14 stars in the direction towards the SNR RX J0852.0-4622 in an attempt to detect broad absorption lines of unshocked ejecta against background stars. Methods. Spectral synthesis is performed for all the stars in the wavelength range of 3740-4020 angstrom to extract the broad absorption lines of Ca II related to the SNR RX J0852.0-4622. Results. We do not detect any broad absorption line and place a 3 sigma upper limit on the relative depths of <0.04 for the broad Ca II absorption produced by the SNR. We detect narrow low and high velocity absorption components of Ca II. High velocity vertical bar V(LSR)vertical bar similar to 100-140 km s(-1) components are attributed to radiative shocks in clouds engulfed by the old Vela SNR. The upper limit to the absorption line strength combined with the width and flux of the (44)Ti gamma-ray line 1.16 MeV lead us to conclude that SNR RX J0852.0-4622 was probably produced by an energetic SN Ic explosion.
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| 17. |
- Kochukhov, Oleg, et al.
(författare)
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Putting atomic diffusion theory of magnetic ApBp stars to the test : evaluation of the predictions of time-dependent diffusion models
- 2018
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Ingår i: Monthly notices of the Royal Astronomical Society. - : OXFORD UNIV PRESS. - 0035-8711 .- 1365-2966. ; 474:2, s. 2787-2795
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Tidskriftsartikel (refereegranskat)abstract
- A series of recent theoretical atomic diffusion studies has address the challenging problem of predicting inhomogeneous vertical and horizontal chemical element distributions in the atmospheres of magnetic ApBp stars. Here we critically assess the most sophisticated of such diffusion models - based on a time-dependent treatment of the atomic diffusion in a magnetized stellar atmosphere - by direct comparison with observations as well by testing the widely used surface mapping tools with the spectral line profiles predicted by this theory. We show that the mean abundances of Fe and Cr are grossly underestimated by the time-dependent theoretical diffusion model, with discrepancies reaching a factor of 1000 for Cr. We also demonstrate that Doppler imaging inversion codes, based either on modelling of individual metal lines or line-averaged profiles simulated according to theoretical three-dimensional abundance distribution, are able to reconstruct correct horizontal chemical spot maps despite ignoring the vertical abundance variation. These numerical experiments justify a direct comparison of the empirical two-dimensional Doppler maps with theoretical diffusion calculations. This comparison is generally unfavourable for the current diffusion theory, as very few chemical elements are observed to form overabundance rings in the horizontal field regions as predicted by the theory and there are numerous examples of element accumulations in the vicinity of radial field zones, which cannot be explained by diffusion calculations.
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| 18. |
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| 19. |
- Kuschnig, R., Ryabchikova, T.A., Piskunov, N., Weiss, W.W., LeContel, J.M.
(författare)
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The atmosphere of the peculiar binary system ET Andromedae
- 1995
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Ingår i: Astronomy & Astrophysics. - : EDP Sciences. - 0004-6361. ; 294:3, s. 757-
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Tidskriftsartikel (refereegranskat)abstract
- High spectral resolution, high signal-to-noise OHP spectra which cover the range from 4000A to 7500A were used to derive abundances for ET And. An extreme overabundance of silicon by nearly 100 times of the solar value corroborates the Si-star classificat
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| 20. |
- Pakhomov, Yu, V, et al.
(författare)
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Hyperfine Splitting in the VALD Database of Spectral-line Parameters
- 2019
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Ingår i: Astronomy reports (Print). - : PLEIADES PUBLISHING INC. - 1063-7729 .- 1562-6881. ; 63:12, s. 1010-1021
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Tidskriftsartikel (refereegranskat)abstract
- The Vienna Atomic Line Database (VALD) has been supplemented with new data and new functionality-the possibility of taking into account the effect of hyperfine splitting (HFS) of atomic levels in the analysis of line profiles. This has been done through the creation of an ancillary SQL database with the HFS constants for atomic levels of 58 isotopes of 30 neutral and singly-ionized atoms. The completeness of the collected data and new opportunities for studies of stars of various spectral types is analyzed. The database enables analysis of splitting of up to 60% of lines with measurable effects in the ultraviolet (lambda >= 1000 angstrom), and up to 100% of such lines in the optical and infrared ranges (lambda >= 25 000 angstrom) for A-M stars. In the spectra of hot O-B stars, it is necessary to use laboratory measurements for atoms in the second and higher stages of ionization.
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| 21. |
- Piskunov, Nikolai, et al.
(författare)
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Methodology for measuring fundamental parameters and associated uncertainties for middle and cool main-sequence stars
- 2014
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Ingår i: PUTTING A STARS INTO CONTEXT. - 9785000862735 ; , s. 130-135
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Konferensbidrag (refereegranskat)abstract
- We have performed a study of a representative group of main-sequence stars in the temperature range 5000-10000 K in order to test our methodology for determining fundamental parameters and for the assesment of associated uncertainties. The stars selected have reasonably well-established parameters. This paper presents all the steps of our method, from the selection of spectral intervals and atomic/molecular data, to the determination of effective temperatures, surface gravities and metallicities.
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| 22. |
- Potravnov, I., et al.
(författare)
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Doppler imaging of a southern ApSi star HD 152564
- 2023
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press. - 0035-8711 .- 1365-2966. ; 527:4, s. 10376-10387
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Tidskriftsartikel (refereegranskat)abstract
- We present the results of the spectroscopic study of a chemically peculiar star HD 152564. Using medium-resolution (R = 37 000) observations obtained with the high-resolution fibre échelle spectrograph mounted on the South African Large Telescope, we determined atmospheric parameters Teff = 11 950 ± 200 K and log g = 3.6 ± 0.2 dex. Abundance analysis revealed mild deficiency of the light elements and an overabundance of up to ∼2 dex of metals, with the greatest excess for silicon. With these characteristics, HD 152564 is a typical member of the silicon subgroup of Ap stars. The rotational modulation of the light curve and line profiles of HD 152564 are typical for the inhomogeneous surface distribution of elements in its atmosphere. We performed multi-element Doppler imaging of the surface of HD 152564. Abundance maps constructed for He, O, Mg, Si, and Fe revealed the concentration of these elements in a sequence of equatorial spots as well as in the circumpolar rings. The photometric maximum of the light curve coincided with the visibility of two most overabundant silicon spots. Abundances determined from the different ionization stages of Fe and Si show clear evidence for vertical stratification of these elements in the atmosphere of HD 152564. Meanwhile, the horizontal distribution of silicon reconstructed from the lines of different ionization stages and excitation energies appears to be identical with increasing average abundance deeper in atmosphere.
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| 23. |
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| 24. |
- Ryabchikova, T., et al.
(författare)
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Rare-earth elements in the atmosphere of the magnetic chemically peculiar star HD 144897
- 2006
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 456:1, s. 329-338
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Tidskriftsartikel (refereegranskat)abstract
- Context. The chemically peculiar stars of the upper main sequence represent a natural laboratory for the study of rare- earth elements (REE). Aims. We want to check the reliability of the energy levels and atomic line parameters for the second REE ions currently available in the literature, and obtained by means of experiments and theoretical calculations. Methods. We have obtained a UVES spectrum of a slowly rotating strongly magnetic Ap star, HD 144897, that exhibits very large overabundances of rare- earth elements. Here we present a detailed spectral analysis of this object, taking effects of non- uniform vertical distribution (stratification) of chemical elements into account. Results. We determined the photospheric abundances of 40 ions. For seven elements (Mg, Si, Ca, Ti, Cr, Mn, Fe), we obtained a stratification model that allows us to produce a satisfactory fit to the observed profiles of spectral lines of various strengths. All the stratified elements but Cr show a steep decrease in concentration toward the upper atmospheric layers; for Cr the transition from high to low concentration regions appears smoother than for the other elements. The REEs abundances, which have been determined for the first time from the lines of the first and second ions, have been found typically four dex higher than solar abundances. Our analysis of REE spectral lines provides strong support for the laboratory line classification and determination of the atomic parameters. The only remarkable exception is Nd III, for which spectral synthesis was found to be inconsistent with the observations. We therefore performed a revision of the Nd III classification. We confirmed the energies for 11 out of 24 odd energy levels that were classified previously, and derived the energies for additional 24 levels of Nd III, thereby substantially increasing the number of classified Nd III lines with corrected wavelengths and atomic parameters.
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| 25. |
- Wade, G.A., et al.
(författare)
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Chemical Stratification in Magnetic Ap Stars
- 2001
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Ingår i: Magnetic Fields Across the Hertzsprung-Russell Diagram, ASP Conf. Ser., vol. 248. ; , s. 373-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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