VizieR Online Data Catalog: SDSS distant sample of halo wide binaries (Coronado+, 2018)
Abstract
We selected our sample using proper motions and photometry from the SDSS. We use DR9, which has the advantage of correcting errors in proper motions, previously present for DR7 stars at low Galactic latitudes. Using the aforementioned query, we choose stars from DR9 with SDSS r-band magnitudes 14<r<20 and proper motions μ>30mas/yr. This latter imposed criterion over the proper motions significantly decreases the density of stars, especially more distant ones, which in turn considerably decreases the probability of chance alignments. For the query, PSF magnitudes were chosen, with their corresponding extinction coefficients. In order to have reliable photometry we follow Sesar, Ivezic & Juric (2008ApJ...689.1244S) to select real sources. For the candidates that passed our selection criteria, we obtained long-slit spectra. Observations were carried with the COSMOS instrument at the Blanco telescope in Cerro Tololo Inter-American Observatory (CTIO) with the blue VPH grism covering a wavelength range of 5600-9600Å and a 0.9arcsec slit reaching a spectral resolution of ~2100. Also with the EFOSC2 spectrograph at the New Technology Telescope (NTT) in La Silla with grism #20 covering a wavelength range of 6047-7147Å and a 0.5arcsec slit reaching a spectral resolution of ~3200. Finally, with the KOSMOS instrument at the Kitt Peak National Observatory (KPNO) with the red VPH grism covering a wavelength range of 5600-9600Å and a 0.9 arcsec slit reaching a spectral resolution of ~2200. From the initial sample of 400 candidate pairs, we obtained spectra for 88 pairs.
(1 data file).- Publication:
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VizieR Online Data Catalog
- Pub Date:
- May 2022
- Bibcode:
- 2022yCat..74804302C
- Keywords:
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- Stars: double and multiple;
- Positional data;
- Radial velocities;
- Proper motions;
- Optical