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The Stars of the HETDEX Survey. I. Radial Velocities and Metal-poor Stars from Low-resolution Stellar Spectra.
- Source :
- Astrophysical Journal; 4/20/2021, Vol. 911 Issue 2, p1-13, 13p
- Publication Year :
- 2021
-
Abstract
- The Hobby–Eberly Telescope Dark Energy Experiment (HETDEX) is an unbiased, massively multiplexed spectroscopic survey, designed to measure the expansion history of the universe through low-resolution (R ∼ 750) spectra of Lyα emitters. In its search for these galaxies, HETDEX will also observe a few times 10<superscript>5</superscript> stars. In this paper, we present the first stellar value-added catalog within the internal second data release of the HETDEX Survey (HDR2). The new catalog contains 120,571 low-resolution spectra for 98,736 unique stars between 10 < G < 22 spread across the HETDEX footprint at relatively high (b ∼ 60°) Galactic latitudes. With these spectra, we measure radial velocities (RVs) for ∼42,000 unique FGK-type stars in the catalog and show that the HETDEX spectra are sufficient to constrain these RVs with a 1σ precision of 28.0 km s<superscript>−1</superscript> and bias of 3.5 km s<superscript>−1</superscript> with respect to the Large Sky Area Multi-Object Fibre Spectroscopic Telescope surveys and 1σ precision of 27.5 km s<superscript>−1</superscript> and bias of 14.0 km s<superscript>−1</superscript> compared to the Sloan Extension for Galactic Understanding and Exploration survey. Since these RVs are for faint (G ≥ 16) stars, they will be complementary to Gaia. Using t-Distributed Stochastic Neighbor Embedding (tSNE), we also demonstrate that the HETDEX spectra can be used to determine a star's T<subscript>eff</subscript>, and log g and its [Fe/H]. With the tSNE projection of the FGK-type stars with HETDEX spectra we also identify 416 new candidate metal-poor ([Fe/H] < −1 dex) stars for future study. These encouraging results illustrate the utility of future low-resolution stellar spectroscopic surveys. [ABSTRACT FROM AUTHOR]
- Subjects :
- RADIAL velocity of stars
PHYSICAL cosmology
DARK energy
STELLAR spectra
Subjects
Details
- Language :
- English
- ISSN :
- 0004637X
- Volume :
- 911
- Issue :
- 2
- Database :
- Complementary Index
- Journal :
- Astrophysical Journal
- Publication Type :
- Academic Journal
- Accession number :
- 150103144
- Full Text :
- https://doi.org/10.3847/1538-4357/abe9bd