Faint Near-ultraviolet/Far-ultraviolet Standards from Swift/UVOT, GALEX, and SDSS Photometry

Siegel, Michael H.; Hoversten, Erik A.; Roming, Peter W. A.; Landsman, Wayne B.; Allende-Prieto, C.; Breeveld, Alice A.; Brown, Peter; Holland, Stephen T.; Kuin, N. P. M.; Page, Mathew J.; Vanden Berk, Daniel E.
Referencia bibliográfica

The Astrophysical Journal, Volume 725, Issue 1, pp. 1215-1225 (2010).

Fecha de publicación:
12
2010
Número de autores
11
Número de autores del IAC
1
Número de citas
8
Número de citas referidas
5
Descripción
At present, the precision of deep ultraviolet photometry is somewhat limited by the dearth of faint ultraviolet standard stars. In an effort to improve this situation, we present a uniform catalog of 11 new faint (u ~ 17) ultraviolet standard stars. High-precision photometry of these stars has been taken from the Sloan Digital Sky Survey and Galaxy Evolution Explorer archives and combined with new data from the Swift Ultraviolet Optical Telescope to provide precise photometric measures extending from the near-infrared to the far-ultraviolet. These stars were chosen because they are known to be hot (20, 000 < T eff < 50, 000 K) DA white dwarfs with published Sloan spectra that should be photometrically stable. This careful selection allows us to compare the combined photometry and Sloan spectroscopy to models of pure hydrogen atmospheres to both constrain the underlying properties of the white dwarfs and test the ability of white dwarf models to predict the photometric measures. We find that the photometry provides good constraints on white dwarf temperatures, which demonstrates the ability of Swift/UVOT to investigate the properties of hot luminous stars. We further find that the models reproduce the photometric measures in all 11 passbands to within their systematic uncertainties. Within the limits of our photometry, we find the standard stars to be photometrically stable. This success indicates that the models can be used to calibrate additional filters to our standard system, permitting easier comparison of photometry from heterogeneous sources. The largest source of uncertainty in the model fitting is the uncertainty in the foreground reddening curve, a problem that is especially acute in the UV.
Proyectos relacionados
spectrum of mercury lamp
Abundancias Químicas en Estrellas
La espectroscopía de estrellas nos permite determinar las propiedades y composiciones químicas de las mismas. A partir de esta información para estrellas de diferente edad en la Vía Láctea es posible reconstruir la evolución química de la Galaxia, así como el origen de los elementos más pesados que el boro, forjados principalmente en los interiores
Carlos
Allende Prieto