The relative calibration of radial velocity for LAMOST medium resolution stellar spectra

Xiong, Jian-Ping; Zhang, Bo; Liu, Chao; Li, Jiao; Zhao, Yi; Hou, Yonghui

doi:10.1088/1674-4527/21/10/265

Cited by 3 publications

(4 citation statements)

References 28 publications

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“…The systematic uncertainty in v r is 0.25 km s −1 for R  5000 and ∼1 km s −1 for R ∼ 2500. These spreads are large compared to the formal measurement uncertainties (0.1-0.6 km s −1 ), but on par with expectations for low-and medium-resolution surveys (e.g., Xiong et al 2021).…”

Section: Atmospheric Parameterssupporting

confidence: 56%

Validating Stellar Abundance Measurements from Multiresolution Spectroscopy

Sandford

Weisz

Ting

2023

ApJS

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Large-scale surveys will provide spectroscopy for ∼50 million resolved stars in the Milky Way and Local Group. However, these data will have a high degree of heterogeneity and most will be low-resolution (R < 10,000), posing challenges to measuring consistent and reliable stellar labels. Here, we introduce a framework for identifying and remedying these issues. By simultaneously fitting the full spectrum and Gaia photometry with the Payne, we measure ∼30 abundances for eight metal-poor red giants in M15. From degraded quality Keck/HIRES spectra, we evaluate trends with resolution and signal-to-noise ratio (S/N) and find that (i) ∼20 abundances are recovered consistently within ≲0.1 dex agreement and with ≲0.05–0.15 dex systematic uncertainties from 10,000 ≲ R ≲ 80,000; (ii) for nine elements (C, Mg, Ca, Sc, Ti, Fe, Ni, Y, and Nd), this systematic precision and accuracy extends down to R ∼ 2500; and (iii) while most elements do not exhibit strong S/N-dependent systematics, there are nonnegligible biases for four elements (C, Mg, Ca, and Dy) below S/N ∼ 10 pixel−1. We compare statistical uncertainties from Markov Chain Monte Carlo sampling to the easier-to-compute Cramér–Rao bounds and find that they agree for ∼85% of elements, indicating the latter to be a reliable and faster way to estimate uncertainties. Our analysis illustrates the great promise of low-resolution spectroscopy for stellar chemical abundance work in the low-metallicity regime, and ongoing improvements to stellar models (e.g., 3D-NLTE physics) will only further extend its viability to more stars, more elements, and higher precision and accuracy.

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Section: Atmospheric Parameterssupporting

confidence: 56%

Validating Stellar Abundance Measurements from Multiresolution Spectroscopy

Sandford

Weisz

Ting

2023

ApJS

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“…The uncertainty of radial velocities of LAMOST MRS spectra is around 1 km s −1 for late-type stars Zhang et al 2021;Xiong et al 2021), the stellar atmospheric parameters (T eff and log g) and 13 chemical abundances are derived for LAMOST MRS by a deep-learning method with uncertainties of 119 K, 0.17 dex, and 0.06∼0.12 dex for T eff , log g, and elemental abundances, respectively (Wang et al 2020). As expected, the rotation of the stars can also be determined under uncertainty of 10 km s −1 .…”

Section: Lamost Data With Light Curvesmentioning

confidence: 99%

“…For LAMOST low-resolution spectra (LRS with R∼1800), the accuracy of radial velocity, T eff , log g and [Fe/H] are around 5 km s −1 , 150 K, 0.25 dex, and 0.15 dex, respectively (Xiang et al 2015). For LAM-OST MRS, the accuracy of radial velocity can reach around 1 km s −1 Zhang et al 2021;Xiong et al 2021). The accuracy of T eff , log g, and [Fe/H] are around 119 K, 0.17 dex, and 0.06∼0.12 dex, respectively (Wang et al 2020).…”

Section: Introductionmentioning

confidence: 99%

The Eclipsing Binaries from the LAMOST Medium-resolution Survey.III. A High-precision Empirical Stellar Mass Library

Xiong¹,

Liu²,

Li³

et al. 2022

Preprint

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High-precision stellar mass and radius measured directly from binaries can effectively calibrate the stellar models. However, such a database containing full spectral types and large range of metallicity is still not fully established. A continuous effort of data collecting and analysis are requested to complete the database. In this work, we provide a catalog containing 184 binaries with independent atmospheric parameters and accurate masses and radii as the benchmark of stellar mass and radius. The catalog contains 56 new detached binaries from LAMOST Medium-resolution spectroscopic (MRS) survey and 128 detached eclipsing binaries compiled from previous studies. We obtain the orbital solutions of the new detached binaries with uncertainties of masses and radii smaller than 5%. These new samples densify the distribution of metallicity of the high-precision stellar mass library and add 9 hot stars with T eff > 8000 K. Comparisons show that these samples well agree with the PARSEC isochrones in T eff -log g-mass-radius-luminosity space. We compare mass and radius estimates from isochrone and SED fitting, respectively, with those from the binary orbital solution. We find that the precision of the stellar-model dependent mass estimates is > 10% and the precision of the radius estimates based on atmospheric parameters is > 15%. These give a general view of the uncertainty of the usual approaches to estimate stellar mass and radius.

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“…For LAMOST lowresolution spectra (LRS with R ∼ 1800), the accuracies of radial velocity, T eff , logg, and [Fe/H] are around 5 km s −1 , 150 K, 0.25 dex, and 0.15 dex, respectively (Xiang et al 2015). For LAMOST MRS, the accuracy of radial velocity can reach around 1 km s −1 Zhang et al 2021;Xiong et al 2021). The accuracies of T eff , logg, and [Fe/H] are around 119 K, 0.17 dex, and 0.06-0.12 dex, respectively (Wang et al 2020).…”

Section: Introductionmentioning

confidence: 99%

The Eclipsing Binaries from the LAMOST Medium-resolution Survey. III. A High-precision Empirical Stellar Mass Library

Xiong

Liu

et al. 2023

Self Cite

View full text Add to dashboard Cite

High-precision stellar masses and radii measured directly from binaries can effectively calibrate stellar models. However, such a database containing full spectral types and a large range of metallicity is still not fully established. A continuous effort of data collection and analysis is requested to complete the database. In this work, we provide a catalog containing 184 binaries with independent atmospheric parameters and accurate masses and radii as the benchmark for stellar mass and radius. The catalog contains 56 new detached binaries from the LAMOST medium-resolution spectroscopic survey and 128 detached eclipsing binaries compiled from previous studies. We obtain the orbital solutions of the new detached binaries with uncertainties of masses and radii smaller than 5%. These new samples densify the distribution of metallicity of the high-precision stellar mass library and add nine hot stars with T eff > 8000 K. Comparisons show that these samples agree well with the PARSEC isochrones in T eff–logg–mass–radius–luminosity space. We compare mass and radius estimates from isochrone and spectral energy distribution fitting, respectively, with those from the binary orbital solution. We find that the precision of the stellar-model-dependent mass estimates is >10% and the precision of the radius estimates based on atmospheric parameters is >15%. These give a general view of the uncertainty of the usual approaches to estimate stellar mass and radius.

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The relative calibration of radial velocity for LAMOST medium resolution stellar spectra

Cited by 3 publications

References 28 publications

Validating Stellar Abundance Measurements from Multiresolution Spectroscopy

Validating Stellar Abundance Measurements from Multiresolution Spectroscopy

The Eclipsing Binaries from the LAMOST Medium-resolution Survey.III. A High-precision Empirical Stellar Mass Library

The Eclipsing Binaries from the LAMOST Medium-resolution Survey. III. A High-precision Empirical Stellar Mass Library

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