Marvels (multi-object Apo Radial Velocity Exoplanet Large-area Survey)Target Selection.
Abstract
We present the target and field selection strategy for MARVELS (Multi-object APO Radial Velocity Exoplanet Large-area Survey), one of the four surveys that forms SDSS-III. MARVELS will provide precise radial velocities for ∼ 11,000 (7.6 < V < 12) stars during the next six years. The target fields for MARVELS were chosen to have high observing cadence and known radial velocity references throughout the survey. The targets were selected from GSC2.3 and 2MASS catalogs (with 7.6 < V 0.29). The selection procedure is designed to create a sample with transparent and well understood biases against spectral type, ages and metallicities. Each field is pre-surveyed to obtain medium resolution spectra (R=2000) for 272-540 stars, fainter than 9th magnitude, using SDSS spectrographs. We select the 60 brightest stars in each field (for the first two years of the survey), with Teff ≤ 6250 and logg ≥ 3.0, based on the spectroscopic parameters from the SDSS spectra (for stars 9 < V < 12 ) or a reduced proper motion diagram (for stars 7.6 < V < 9), for radial velocity monitoring. We also limit the number of F stars for radial velocity monitoring in each field to be less than 40%. We do not impose selections based on the age, activity or metallicities. Based on the already pre-surveyed fields, we expect about 20 late-F and 40 G-K subgiants and dwarfs brighter than 11.5 mag in each field for the final RV monitoring. MARVELS target fields also contain several Kepler fields, which complements both the survey efforts. We shall also discuss the accuracy of stellar parameters determined from the pre-survey SDSS spectra and compare them with high-resolution estimation, for few reference stars.
We would like to thank the Sloan Foundation, NSF and UF for support.- Publication:
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American Astronomical Society Meeting Abstracts #213
- Pub Date:
- January 2009
- Bibcode:
- 2009AAS...21340507S