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The Stars of the HETDEX Survey. I. Radial Velocities and Metal-poor Stars from Low-resolution Stellar Spectra.

Authors :
Hawkins, Keith
Zeimann, Greg
Sneden, Chris
Cooper, Erin Mentuch
Gebhardt, Karl
Bond, Howard E.
Carrillo, Andreia
Casey, Caitlin M.
Castanheira, Barbara G.
Ciardullo, Robin
Davis, Dustin
Farrow, Daniel J.
Finkelstein, Steven L.
Hill, Gary J.
Kelz, Andreas
Liu, Chenxu
Shetrone, Matthew
Schneider, Donald P.
Starkenburg, Else
Steinmetz, Matthias
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]

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