相关论文: Synthetic spectra for O and B type subdwarf stars
The program package SME (Spectroscopy Made Easy), designed to perform an analysis of stellar spectra using spectral fitting techniques, was updated due to adding new functions (isotopic and hyperfine splittins) in VALD and including grids…
Libraries of stellar spectra find many uses in astrophysics, from photometric calibration to stellar population synthesis. We present low resolution spectra of 40 stars from 0.2 micrometers (ultraviolet) to 1.0 micrometers (near infrared)…
We present mid-infrared observations for a sample of 16 O-type stars. The data were acquired with the NASA Spitzer Space Telescope, using the IRS instrument at moderate resolution (R $\sim$ 600), covering the range $\sim 10-37$ microns. Our…
Spectral analysis by means of Non-LTE model-atmosphere techniques has arrived at a high level of sophistication: fully line-blanketed model atmospheres which consider opacities of all elements from H to Ni allow the reliable determination…
Arguments for including in the VO large grids of synthetic spectra fully covering the HR diagram are presented. One obvious need is that of population synthesis at all redshifts. Theoretical spectra have also the power to predict peculiar…
We use synthetic model spectra to investigate the potential of near-ultraviolet (3000-4050 \r{A}) observations of massive O-type stars. We highlight the He I $\lambda$3188 and He II $\lambda$3203 pair as a potential temperature diagnostic…
Context. The surface structures and dynamics of cool stars are characterized by the presence of convective motions and turbulent flows which shape the emergent spectrum. Aims. We used realistic three-dimensional radiative hydrodynamical…
We have generated a set of far-ultraviolet stellar libraries using spectra of OB and Wolf-Rayet stars in the Galaxy and the Large and Small Magellanic Cloud. The spectra were collected with the Far Ultraviolet Spectroscopic Explorer and…
We present a technique to synthesise telluric absorption and emission features both for in-situ wavelength calibration and for their removal from astronomical spectra. While the presented technique is applicable for a wide variety of…
We present an investigation of synthetic spectroscopic indices that can plausibly help in identifying the presence of multiple stellar populations in globular clusters. The study is based on a new grid of stellar model atmospheres and…
Theoretical atmosphere models provide the basis for a variety of applications in astronomy. In simplified one-dimensional (1D) atmosphere models, convection is usually treated with the mixing length theory despite its well-known…
We present an analysis of high resolution spectra in the far-UV -- UV range (~905-2000\AA) with non-LTE, spherical, hydrodynamical, line-blanketed models, of three O-type Galactic stars, and derive their photospheric and wind parameters.…
The negative hydrogen ion H$^-$ is, almost without exception, treated in local thermodynamic equilibrium (LTE) in the modelling of F, G, and K stars, where it is the dominant opacity source in the visual spectral region. This assumption…
The study of Stark broadening of neutral helium lines, despite significant advances over recent decades, has not led to updated large grids of helium line profiles relevant to the spectroscopic study of helium-rich stars. While the…
I have carried out spectrum synthesis of R = 120,000 spectra of several A and B stars having v sin i less than about 6 km/s. The following conclusions emerge: (1) As T_e descends from 12,000 to 8,000 K, microturbulent velocity xi deduced…
S-type stars are late-type giants whose atmosphere is enriched in carbon and s-process elements because of either extrinsic pollution by a binary companion or intrinsic nucleosynthesis and dredge-up on the thermally-pulsing AGB. A large…
A comprehensive hybrid library of synthetic stellar spectra based on three original grids of model atmosphere spectra by Kurucz (1995), Fluks et al. (1994), and Bessell et al. (1989, 1991) is presented. The combined library is intended for…
Preliminary analysis of CCD spectra obtained by the 6m SAO telescope is presented. We have used simple H-He NLTE model atmospheres computed by TLUSTY to derive the basic parameters of the star.
The IACOB and OWN surveys are two ambitious complementary observational projects which have made available a large multi-epoch spectroscopic database of optical high resolution spectra of Galactic massive O-type stars. As a first step in…
In the framework of the Virtual Observatory (VO), the German Astrophysical Virtual Observatory (GAVO) developed the registered service TheoSSA (Theoretical Stellar Spectra Access). It provides easy access to stellar spectral energy…