A selection of hot subluminous stars in the GALEX survey II. Subdwarf atmospheric parameters

Abstract

We present an update of our low-resolution spectroscopic follow-up and model atmosphere analysis of hot subdwarf stars from the Galaxy Evolution Explorer (GALEX) survey. Targets were selected on the basis of colour indices calculated from the GALEX GR6 N_UV, Guide Star Catalogue (GSC2.3.2) V and the Two Micron All Sky Survey (2MASS) J and H photometry. High signal-to-noise ratio spectra were obtained at the European Southern Observatory (ESO) and the Kitt Peak National Observatory (KPNO) over the course of three years. Detailed H, He and CNO abundance analysis helped us improve our T_eff, log g and He abundance determination and to constrain CNO abundances. We processed 191 observations of 180 targets and found 124 sdB and 42 sdO stars in this sample while some blue horizontal branch stars were also found in this programme. With quantitative binary decomposition of 29 composite spectra we investigated the incidence of A, F and G type companions. The incidence of late G and K type companions and their effects on subdwarf atmospheric parameters were also examined.

33 pages, 25 figures and 6 tables. Accepted for publication in MNRAS. Typos corrected and note added in proof

References in corpus (13)

• A Grid of NLTE Line-Blanketed Model Atmospheres of Early B-type Stars
• The Second-Generation Guide Star Catalog: Description and Properties
• Medium-resolution Isaac Newton Telescope library of empirical spectra - II. The stellar atmospheric parameters
• Hot subdwarfs from the ESO Supernova Ia Progenitor Survey: II. Atmospheric parameters of subdwarf O stars
• Modeling He-rich subdwarfs through the hot-flasher Scenario
• Abundance studies of sdB stars using UV echelle HST/STIS spectroscopy
• Gravity-mode pulsations in subdwarf B stars: a critical test of stellar opacity
• Mass-loss and diffusion in subdwarf B stars and hot white dwarfs: do weak winds exist?
• Discovery of a Bright, Extremely Low-Mass White Dwarf in a Close Double Degenerate System
• A seismic approach to testing different formation channels of subdwarf B stars
• KIC 1718290: A Helium-rich V1093-Her-like Pulsator on the Blue Horizontal Branch
• Identification of blue high proper motion objects in the Tycho-2 and 2MASS catalogues using Virtual Observatory tools
• Hot subdwarf binaries - Masses and nature of their heavy compact companions

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