Validation of LAMOST Stellar Parameters with the PASTEL Catalog

TL;DR

This study validates LAMOST DR1 stellar parameters by comparing them with the PASTEL catalog, confirming their reliability within certain temperature ranges and identifying systematic metallicity differences.

Contribution

It provides a validation of LAMOST DR1 stellar parameters using the PASTEL catalog, establishing their accuracy and limitations across specific temperature ranges.

Findings

DR1 stellar parameters are reliable for $T_{eff}<8000K$

Standard deviations: 110K in $T_{eff}$, 0.19 dex in $ ext{log} g$, 0.11 dex in [Fe/H], 4.91 km/s in $V_r$

Metallicities in DR1 are systematically higher than PASTEL for [Fe/H] < -1.5

Abstract

Recently the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) published its first data release (DR1), which is ranked as the largest stellar spectra dataset in the world so far. We combine the PASTEL catalog and SIMBAD radial velocities as a testing standard to validate the DR1 stellar parameters (effective temperature $T_{\mathrm{eff}}$, surface gravity $\log g$, metallicity $\mathrm{[Fe/H]}$ and radial velocity $V_{\mathrm{r}}$). Through cross-identification of the DR1 catalogs and the PASTEL catalog, we obtain a preliminary sample of 422 stars. After removal of stellar parameter measurements from problematic spectra and applying effective temperature constraints to the sample, we compare the stellar parameters from DR1 with those from PASTEL and SIMBAD to prove that the DR1 results are reliable in restricted $T_{\mathrm{eff}}$ ranges. We derive standard deviations of 110 K, 0.19 dex, 0.11 dex and 4.91 $\mathrm{km\,s^{-1}}$ , for $T_{\mathrm{eff}}$, $\log g$, $[\mathrm{Fe/H}]$ when $T_{\mathrm{eff}}<8000\,\mathrm{K}$, and for $V_{\mathrm{r}}$ when $T_{\mathrm{eff}}<10000\,\mathrm{K}$, respectively. Systematic errors are negligible except for that of $V_{\mathrm{r}}$. Besides, metallicities in DR1 are systematically higher than those in PASTEL, in the range of PASTEL $[\mathrm{Fe/H}]<-1.5$.