Mapping the Milky Way with LAMOST I: method and overview

  title={Mapping the Milky Way with LAMOST I: method and overview},
  author={Chao Liu and Yan Xu and Jun-chen Wan and Haifeng Wang and Jeffrey L. Carlin and Licai Deng and Heidi Jo Newberg and Zihuang Cao and Yong-Hui Hou and Yue-fei Wang and Yong Zhang},
  journal={Research in Astronomy and Astrophysics},
We present a statistical method to derive the stellar density profiles of the Milky Way from spectroscopic survey data, taking into account selection effects. We assume the selection function, which can be altered during observations and data reductions, of the spectroscopic survey is based on photometric colors and magnitude. Then the underlying selection function for a line-of-sight can be recovered well by comparing the distribution of the spectroscopic stars in a color-magnitude plane with… Expand
Effects of the selection function on metallicity trends in spectroscopic surveys of the Milky Way
We investigate here the effect of the selection function on the metallicity distribution function (MDF) and on the vertical metallicity gradient by studying similar lines of sight using fourExpand
The first all-sky view of the Milky Way stellar halo with Gaia+2MASS RR Lyrae
We exploit the first Gaia data release to study the properties of the Galactic stellar halo as traced by RR Lyrae. We demonstrate that it is possible to select a pure sample of RR Lyrae using onlyExpand
Dynamical Model of the Milky Way Using APOGEE and Gaia Data
We construct a dynamical model of the Milky Way disk from a data set that combines Gaia EDR3 and APOGEE data throughout galactocentric radii in the range 5.0 kpc ≤ R ≤ 19.5 kpc. We make use of theExpand
Mapping the Milky Way with LAMOST – II. The stellar halo
The radial number density and flattening of the Milky Way's stellar halo is measured with $\mathrm{5351}$ metal-poor ([Fe/H]$<-1$) K giants from LAMOST DR3, using a nonparametric method which isExpand
Disk stars in the Milky Way detected beyond 25 kpc from its center
CONTEXT. The maximum size of the Galactic stellar disk is not yet known. Some studies have suggested an abrupt drop-off of the stellar density of the disk at Galactocentric distances $R\gtrsim 15$Expand
Red Clump Stars from LAMOST II: the outer disc of the Milky Way
We present stellar density maps of the Galactic outer disc with red clump stars from LAMOST data. These samples are separated into younger (mean age ∼ 2.7 Gyr) and older (mean age ∼ 4.6 Gyr)Expand
Measuring the local dark matter density with LAMOST DR5 and Gaia DR2
We apply the vertical Jeans equation to the kinematics of Milky Way stars in the solar neighbourhood to measure the local dark matter density. More than 90,000 G- and K-type dwarf stars are selectedExpand
A Tidally Induced Global Corrugation Pattern in an External Disk Galaxy Similar to the Milky Way
We study the two-dimensional (2D) line-of-sight velocity (V los) field of the low-inclination, late-type galaxy VV304a. The resulting 2D kinematic map reveals a global, coherent, and extendedExpand
Mapping the Milky Way with LAMOST– III. Complicated spatial structure in the outer disc
We present {complexity} of the Galactic outer disc {by fitting the stellar volume densities of the red giant branch stars with a two-disc component model}. {The discs are confirmed to} extend toExpand
The age–velocity dispersion relation of the Galactic discs from LAMOST–Gaia data
We present the age-velocity dispersion relation (AVR) in three dimensions in the solar neighbourhood using 3,564 commonly observed sub-giant/red-giant branch stars selected from LAMOST, which givesExpand


The Milky Way Tomography with SDSS. I. Stellar Number Density Distribution
Using the photometric parallax method we estimate the distances to ~48 million stars detected by the Sloan Digital Sky Survey (SDSS) and map their three-dimensional number density distribution in theExpand
The Milky Way Tomography with SDSS. II. Stellar Metallicity
In addition to optical photometry of unprecedented quality, the Sloan Digital Sky Survey (SDSS) is producing a massive spectroscopic database which already contains over 280,000 stellar spectra.Expand
Estimation of distances to stars with stellar parameters from LAMOST
We present a method to estimate distances to stars with spectroscopically derived stellar parameters. The technique is a Bayesian approach with likelihood estimated via comparison of measuredExpand
We characterize the radial density, metallicity, and flattening profile of the Milky Way’s stellar halo, based on the large sample of spectroscopically confirmed giant stars from SDSS/SEGUE-2,Expand
Stellar Population Studies with the SDSS. I. The Vertical Distribution of Stars in the Milky Way
We present star count data from the Sloan Digital Sky Survey for 5.8 × 105 stars brighter than g' = 21 mag over 279 deg2 in two samples north and south of the Galactic plane. Using theseExpand
Automatic determination of stellar atmospheric parameters and construction of stellar spectral templates of the Guoshoujing Telescope (LAMOST)
This work has tested the effect of different resolutions and signal-to-noise ratios (SNR) on the measurement of the stellar atmospheric parameters (effective temperature Teff, surface gravity log g, and metallicity [Fe/H) and showed that ULySS is reliable for determining these parameters with medium-resolution spectra. Expand
The spatial, kinematic, and elemental-abundance structure of the Milky Way's stellar disk is complex, and has been difficult to dissect with local spectroscopic or global photometric data. Here, weExpand
The Milky Way stellar halo out to 40 kpc: squashed, broken but smooth
We introduce a new maximum-likelihood method to model the density profile of blue horizontal branch and blue straggler stars and apply it to the Sloan Digital Sky Survey Data Release 8 photometricExpand
The asymmetric structure of the Galactic halo
Using the stellar photometry catalogue based on the latest data release (DR4) of the Sloan Digital Sky Survey (SDSS), a study of the Galactic structure using star counts is carried out for selectedExpand
Measuring distances and reddenings for a billion stars : toward a 3D dust map from Pan-STARRS 1.
We present a method to infer reddenings and distances to stars based only on their broad-band photometry, and show how this method can be used to produce a three-dimensional (3D) dust map of theExpand