SEGUE: A SPECTROSCOPIC SURVEY OF 240,000 STARS WITH<i>g</i>= 14-20

TLDR

The SEGUE Survey obtained ≈240,000 moderate‑resolution spectra of fainter Milky Way stars (14 < g < 20.3) to investigate the Galaxy’s kinematics and stellar populations. SEGUE collected these spectra in 212 sky regions, measured atmospheric parameters for stars with SNR > 10, and supplemented the data with 3,500 deg² of ugriz imaging for precise target selection. The survey delivers radial‑velocity accuracies better than those at g ≈ 18, degrading toward g ≈ 20, and all spectra, imaging, and derived catalogs are publicly released in SDSS Data Release 7.

Abstract

The Sloan Extension for Galactic Understanding and Exploration (SEGUE) Survey obtained ≈240,000 moderate-resolution (R ∼ 1800) spectra from 3900 Å to 9000 Å of fainter Milky Way stars (14.0 < g < 20.3) of a wide variety of spectral types, both main-sequence and evolved objects, with the goal of studying the kinematics and populations of our Galaxy and its halo. The spectra are clustered in 212 regions spaced over three quarters of the sky. Radial velocity accuracies for stars are at g < 18, degrading to at g ∼ 20. For stars with signal-to-noise ratio >10 per resolution element, stellar atmospheric parameters are estimated, including metallicity, surface gravity, and effective temperature. SEGUE obtained 3500 deg2 of additional ugriz imaging (primarily at low Galactic latitudes) providing precise multicolor photometry (σ(g, r, i) ∼ 2%), (σ(u, z) ∼ 3%) and astrometry (≈01) for spectroscopic target selection. The stellar spectra, imaging data, and derived parameter catalogs for this survey are publicly available as part of Sloan Digital Sky Survey Data Release 7.