Stellar population models in the UV. I. Characterisation of the New Generation Stellar Library
Context. The spectral predictions of stellar population models are notas accurate in the ultra-violet (UV) as in the optical wavelengthdomain. One of the reasons is the lack of high-quality stellarlibraries. The New Generation Stellar Library (NGSL), recently released,represents a significant step towards the improvement of this situation. Aims: To prepare NGSL for population synthesis, we determined theatmospheric parameters of its stars, we assessed the precision of thewavelength calibration and characterised its intrinsic resolution. Wealso measured the Galactic extinction for each of the NGSL stars. Methods: For our analyses we used ULySS, a full spectrum fittingpackage, fitting the NGSL spectra against the MILES interpolator. Results: We find that the wavelength calibration is precise up to 0.1px, after correcting a systematic effect in the optical range. Thespectral resolution varies from 3 Å in the UV to 10 Å in thenear-infrared (NIR), corresponding to a roughly constant reciprocalresolution R = ?/?? ? 1000 and an instrumentalvelocity dispersion ?ins ? 130 km s-1. Wederived the atmospheric parameters homogeneously. The precision for theFGK stars is 42 K, 0.24 and 0.09 dex for Teff, log g and[Fe/H], respectively. The corresponding mean errors are 29 K, 0.50 and0.48 dex for the M stars, and for the OBA stars they are 4.5 percent,0.44 and 0.18 dex. The comparison with the literature shows that ourresults are not biased.Table A1 is only available at CDS via anonymous ftp tocdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/538/A143
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The PASTEL catalogue of stellar parameters
Aims: The PASTEL catalogue is an update of the [Fe/H] catalogue,published in 1997 and 2001. It is a bibliographical compilation ofstellar atmospheric parameters providing (T_eff, log g, [Fe/H])determinations obtained from the analysis of high resolution, highsignal-to-noise spectra, carried out with model atmospheres. PASTEL alsoprovides determinations of the one parameter T_eff based on variousmethods. It is aimed in the future to provide also homogenizedatmospheric parameters and elemental abundances, radial and rotationalvelocities. A web interface has been created to query the catalogue onelaborated criteria. PASTEL is also distributed through the CDS databaseand VizieR. Methods: To make it as complete as possible, the mainjournals have been surveyed, as well as the CDS database, to findrelevant publications. The catalogue is regularly updated with newdeterminations found in the literature. Results: As of Febuary2010, PASTEL includes 30151 determinations of either T_eff or (T_eff,log g, [Fe/H]) for 16 649 different stars corresponding to 865bibliographical references. Nearly 6000 stars have a determination ofthe three parameters (T_eff, log g, [Fe/H]) with a high qualityspectroscopic metallicity.The catalogue can be queried through a dedicated web interface at http://pastel.obs.u-bordeaux1.fr/.It is also available in electronic form at the Centre de DonnéesStellaires in Strasbourg (http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=B/pastel),at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) orvia http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/515/A111
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Pulkovo compilation of radial velocities for 35495 stars in a common system.
Not Available
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New Estimates of the Solar-Neighborhood Massive Star Birthrate and the Galactic Supernova Rate
The birthrate of stars of masses >=10 Msolar is estimatedfrom a sample of just over 400 O3-B2 dwarfs within 1.5 kpc of the Sunand the result extrapolated to estimate the Galactic supernova ratecontributed by such stars. The solar-neighborhood Galactic-plane massivestar birthrate is estimated at ~176 stars kpc-3Myr-1. On the basis of a model in which the Galactic stellardensity distribution comprises a ``disk+central hole'' like that of thedust infrared emission (as proposed by Drimmel and Spergel), theGalactic supernova rate is estimated at probably not less than ~1 normore than ~2 per century and the number of O3-B2 dwarfs within the solarcircle at ~200,000.
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Catalog of Galactic OB Stars
An all-sky catalog of Galactic OB stars has been created by extendingthe Case-Hamburg Galactic plane luminous-stars surveys to include 5500additional objects drawn from the literature. This work brings the totalnumber of known or reasonably suspected OB stars to over 16,000.Companion databases of UBVβ photometry and MK classifications forthese objects include nearly 30,000 and 20,000 entries, respectively.
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He, CNO abundances and v sin i values in He-rich stars
We present projected rotational velocities distribution in He-rich starsagainst normal B type stars as well as the abundance analysis of lightelements and their comparison with results of earlier series. Theanalysis is based on high-resolution observations (R=40000) collected atESO, La Silla, Chile in the optical region and includes 11 stars,amongst them 5 new stars in comparison with an earlier sample. Thedistribution of projected rotational velocities shows a significantexcess of slow rotators, no He-rich stars having v sin i > 130 km/sat the significance level of 99.5%. Based on fully consistent LTEmodels, the helium abundance ranges from 0.1 (solar) to 0.4. Theanalysis on the new sample confirms the results of earlier paper: thelight element abundances display a diverse pattern from under-solar upto above-solar values. Carbon has the same abundance in He-rich and instandard stars for cool He-rich stars, following the predictions ofradiative diffusion in the presence of wind. The star HD149363 appearsrather as He-weak as based on the equivalent widths from R=40 000spectra.
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Light element abundances in He-rich stars
We present an abundance analysis of light elements in He-rich stars. Theanalysis is based on both low and high resolution observations collectedat ESO, La Silla, Chile in the optical region and includes 6 standardsand 21 He-rich stars. Light-element abundances display a diversepattern: they range from under-solar up to above-solar values.
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Age variation of helium abundance in He-rich stars.
Not Available
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A catalogue of [Fe/H] determinations: 1996 edition
A fifth Edition of the Catalogue of [Fe/H] determinations is presentedherewith. It contains 5946 determinations for 3247 stars, including 751stars in 84 associations, clusters or galaxies. The literature iscomplete up to December 1995. The 700 bibliographical referencescorrespond to [Fe/H] determinations obtained from high resolutionspectroscopic observations and detailed analyses, most of them carriedout with the help of model-atmospheres. The Catalogue is made up ofthree formatted files: File 1: field stars, File 2: stars in galacticassociations and clusters, and stars in SMC, LMC, M33, File 3: numberedlist of bibliographical references The three files are only available inelectronic form at the Centre de Donnees Stellaires in Strasbourg, viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5), or viahttp://cdsweb.u-strasbg.fr/Abstract.html
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An Extension of the Case-Hamburg OB Star Surveys
We have extended the Case-Hamburg OB star surveys to b = +- 30 degreesfor l = +- 60 degres using the Curtis Schmidt telescope and 4 degreeobjective prism at the Cerro Tololo Inter-American Observatory. Acatalog of 234 OB stars and other objects with peculiar spectra ispresented along with finding charts for those objects too faint to beincluded on the BD or CD charts. (SECTION: Stars)
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A new list of effective temperatures of chemically peculiar stars. II.
Not Available
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A catalogue of Fe/H determinations - 1991 edition
A revised version of the catalog of Fe/H determinations published by G.Cayrel et al. (1985) is presented. The catalog contains 3252 Fe/Hdeterminations for 1676 stars. The literature is complete up to December1990. The catalog includes only Fe/H determinations obtained from highresolution spectroscopic observations based on detailed spectroscopicanalyses, most of them carried out with model atmospheres. The catalogcontains a good number of Fe/H determinations for stars from open andglobular clusters and for some supergiants in the Magellanic Clouds.
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On dependence of helium abundance upon magnetic field in He-r stars.
Not Available
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The Relation Between Magnetic Field Strength and Helium Abundance in Helium Rich Stars
Not Available
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The nitrogen abundance in the atmospheres of single and binary stars
The nitrogen abundances for 47 single, 11 visual double, and 41 closebinary stars are obtained from high-dispersion Wlambdadeterminations of nitrogen lines using atmospheric models andtheoretical calculations of N II lines, taking LTE errors into account.The mean value of lg N(N) is found to be 8.05 for single stars, 8.50 forclose binaries, and 8.15 for visual double stars. A correlation is foundbetween the nitrogen abundance and the helium and carbon abundances. Itis suggested that considerable mixing between the central part of starsand the atmosphere occurs in binary stars.
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The IUE data base: Homogenizing the IUE object nomenclature
The IUE project started to homogenize the object nomenclature in the IUEdata base. Due to the absence of an official IAU nomenclature hierarchyand in view of the increasing confusion in IUE (and, in general,astronomical) object identifications, the IUE project adopted its ownnomenclature hierarchy. The scheme and problems encountered inestablishing it are described.
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On the Effective Temperatures of Chemically Peculiar Stars
Not Available
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A catalogue of Fe/H determinations, 1984 edition
The present version of the Cayrel de Strobel et al. (1981) catalog ofFe/H abundance ratio determinations contains 1921 values for 1035 stars,which represents an augmentation over the previous publication of 48 and47 percent, respectively. In addition, the literature search conductedis complete up to December, 1983. Stellar metal abundance, effectivetemperature, spectroscopic gravity, spectral type, and photometricindices are covered.
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Observational problems of investigation of stars with anomalous helium lines.
Not Available
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A survey of spectral morphology and rotational velocities among the helium-rich stars
A spectroscopically homogeneous listing of all known members of thehelium-rich B star category is presented together with uniform estimatesof their rotational velocities. Equivalent widths of hydrogen, helium,and metal lines in the spectra of the helium-rich and comparison starsare given. The distribution of rotational velocities is found to beindistinguishable from that of normal early B dwarfs, except for apossible excess of rapid rotators. The existence of metal abundanceanomalies in the helium-rich spectra is critically discussed, as is theidentification of helium-rich stars as massive Population I objects withnormal main sequence cores and surface helium enhancements, or as lowmass highly evolved objects with processed cores.
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Spectral atlas of helium-rich stars
An atlas of coude spectra of 33 helium-rich O- and B-stars and 11comparison stars in the 3700-4600 A spectral range is presented. Theatlas comprises stars with temperatures from 10,000 to 60,000 deg K inwhich He lines are visible in the spectra, and includes variable Hestars; stars with spectral types O8 to B5 and magnitudes (m(v)) lessthan or equal to 11.0 are considered. The purpose of the atlas is togive a sample of spectra in which, from the observational point of view,the differences caused by certain physical parameters includingeffective temperature, logarithm of the gravity and observed rotationalvelocity, can be judged by eye. Mechanisms for He enrichment in theatmosphere are also discussed.
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Four-colour photometry of hydrogen-deficient stars and related objects
Stromgren uvby photometry of hydrogen deficient and helium-weak starssuggests that the 'extreme helium' (= 'hydrogen deficient') stars whichhave been well observed are all variable, probably in a complex way.Previously observed short-term variability of HD 160641 and long-termvariability of HD 168476 are confirmed. There is no evidence forvariability in the intermediate helium stars or the helium-weak stars.
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Radial velocities of southern early-type stars at intermediate galactic latitudes.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1975MNRAS.172..649K&db_key=AST
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H-beta photometry of southern early-type stars and galactic structure away from the plane
H-beta photoelectric photometry is reported for 165 early-type stars atintermediate and high galactic latitudes. The data are combined withearlier UBV and spectroscopic results to determine the stellar spacedistribution. Stars of type B2 and earlier, at distances of up to 1 kpcfrom the galactic plane, appear to follow spiral structure in the plane.The available material, particularly the derived color excesses, is usedto select a number of blue stars which may be subluminous.
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Spectralphotometry and quantitative analysis of the hydrogen-deficient star HD 60344.
Abstract image available at:http://adsabs.harvard.edu/abs/1975A&A....38..351K
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Spectral photometry and quantitative analysis of the helium star HD 168785.
Abstract image available at:http://adsabs.harvard.edu/abs/1974A&A....36..201K
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UBV photometry of southern early-type stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1974MNRAS.168..451H&db_key=AST
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A fine analysis of the helium-rich star HD 184927.
Abstract image available at:http://adsabs.harvard.edu/abs/1974A&A....33..277H
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The composition and evolutionary status of He-rich stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1974ApJ...187..117O&db_key=AST
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Spectralphotometry and quantitative analysis of the hydrogen-deficient stars HD 144941 and CPD -69 2698.
Abstract image available at:http://adsabs.harvard.edu/abs/1973A&A....25..261H
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