1. Spectroscopic follow-up of ultraviolet-excess objects selected from the UVEX survey.
- Author
-
Verbeek, Kars, Groot, Paul J., Scaringi, Simone, Napiwotzki, Ralf, Spikings, Ben, Østensen, Roy H., Drew, Janet E., Steeghs, Danny, Casares, Jorge, Corral-Santana, Jesus M., Corradi, Romano L. M., Deacon, Niall, Drake, Jeremy J., Gänsicke, Boris T., González-Solares, Eduardo, Greimel, Robert, Heber, Ulrich, Irwin, Mike J., Knigge, Christian, and Nelemans, Gijs
- Subjects
- *
ULTRAVIOLET astronomy , *GALAXIES , *FIELD emission , *ASTRONOMICAL photometry , *WHITE dwarf stars , *LATITUDE - Abstract
ABSTRACT We present the results of the first spectroscopic follow-up of 132 optically blue ultraviolet (UV)-excess sources selected from the UV-Excess Survey of the Northern Galactic Plane (UVEX). The UV-excess spectra are classified into different populations and grids of model spectra are fitted to determine spectral types, temperatures, surface gravities and reddening. From this initial spectroscopic follow-up 95 per cent of the UV-excess candidates turn out to be genuine UV-excess sources such as white dwarfs, white dwarf binaries, subdwarf types O and B, emission-line stars and quasi stellar objects. The remaining sources are classified as slightly reddened main-sequence stars with spectral types later than A0V. The fraction of DA white dwarfs is 47 per cent with reddening smaller than E( B − V) ≤ 0.7 mag. Relations between the different populations and their UVEX photometry, Galactic latitude and reddening are shown. A larger fraction of UVEX white dwarfs is found at magnitudes fainter than g > 17 and Galactic latitude smaller than | b| < 4 compared to main-sequence stars, blue horizontal branch stars and subdwarfs. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF