A Catalog of 45,206 Hα Emission-line Stars from LAMOST MRS DR7

Abstract

Stars that exhibit prominent emission lines in their spectra are referred to as emission-line stars, encompassing a wide range of stellar types and indicative of intriguing physical properties. The Large Sky Area Multi-Object fiber Spectroscopic Telescope (LAMOST) has released millions of spectra from its Medium-Resolution Survey (MRS). A small fraction of these spectra exhibit emission lines, yet they remain undiscovered and unanalyzed due to being buried in the vast dataset. We have developed a method based on Derivative Spectroscopy (DS), which provides a novel approach for detecting and identifying emission-line stars by extracting signals from complex backgrounds and estimating spectral line profiles. Applying this method to the $\mathrm{H}\alpha$ spectral line profiles from the LAMOST-MRS Data Release 7 (DR7), we compiled a catalog of emission-line stars using the second- and third-derivative spectra for automated peak detection. This approach also facilitates the classification of $\mathrm{H}\alpha$ emission-line morphologies through a simplified scheme. The catalog comprises 56\,649 spectra with relatively prominent $\mathrm{H}\alpha$ emission lines from 45\,206 unique stars, with each emission-line component accompanied by approximate estimates of its wavelength, amplitude, and width. All $\mathrm{H}\alpha$ spectral lines were classified into three morphological classes under a unified classification scheme: single emission peak (83.0 \%), double emission peaks (5.6 \%), and P Cygni-type profiles (11.5 \%), which encompass both P Cygni and inverse P Cygni features. Through cross-referencing with SIMBAD, 39\,497 stars represent new emission-line sources discovered in our research.

arXiv comment12 pages, 6 figures

References in corpus (43)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• Correcting for the Effects of Interstellar Extinction
• A 3D Dust Map Based on Gaia, Pan-STARRS 1 and 2MASS
• The First Data Release (DR1) of the LAMOST general survey
• Rotation Periods of 34,030 Kepler Main-Sequence Stars: The Full Autocorrelation Sample
• Classical Be Stars: Rapidly Rotating B Stars with Viscous Keplerian Decretion Disks
• The Catalina Surveys Periodic Variable Star Catalog
• The Spitzer Space Telescope Survey of the Orion A & B Molecular Clouds - Part I: A Census of Dusty Young Stellar Objects and a Study of their Mid-IR Variability
• Rotation and differential rotation of active Kepler stars
• A First Catalog of Variable Stars Measured by the Asteroid Terrestrial-impact Last Alert System (ATLAS)
• The Zwicky Transient Facility Catalog of Periodic Variable Stars
• On the use of Gaia magnitudes and new tables of bolometric corrections
• Toward Complete Statistics of Massive Binary Stars: Penultimate Results from the Cygnus OB2 Radial Velocity Survey
• ROTSE All Sky Surveys for Variable Stars I: Test Fields
• Spectroscopic determination of masses (and implied ages) for red giants
• The Spitzer c2d Survey of Weak-line T Tauri Stars II: New Constraints on the Timescale for Planet Building
• The ASAS-SN Catalog of Variable Stars II: Uniform Classification of 412,000 Known Variables
• Stellar Radial Velocities in the Old Open Cluster M67 (NGC 2682) I. Memberships, Binaries, and Kinematics
• Close companions around young stars
• The first INTEGRAL-OMC catalogue of optically variable sources
• Deriving the stellar labels of LAMOST spectra with Stellar LAbel Machine (SLAM)
• Self-consistent Stellar Radial Velocities from LAMOST Medium-Resolution Survey (MRS) DR7
• Classification of X-ray Sources in the XMM-Newton Serendipitous Source Catalog
• K2 Variable Catalogue: Variable Stars and Eclipsing Binaries in K2 Campaigns 1 and 0
• UV variability and accretion dynamics in the young open cluster NGC 2264
• Catalogue of new Herbig Ae/Be and classical Be stars. A machine learning approach to Gaia DR2
• Constraining Metallicity-dependent Mixing and Extra Mixing using [C/N] in Alpha-Rich Field Giants
• High-resolution, H band Spectroscopy of Be Stars with SDSS-III/APOGEE: I. New Be Stars, Line Identifications, and Line Profiles
• Active red giants: close binaries versus single rapid rotators
• New hot subdwarf stars identified in Gaia DR2 with LAMOST DR5 spectra
• The APOGEE-2 Survey of the Orion Star Forming Complex: I. Target Selection and Validation with early observations
• A catalog of early-type Hα emission line stars and 58 newly confirmed Herbig Ae/Bes from LAMOST DR7
• Identification of new classical Be stars from the LAMOST MRS survey
• Active deep learning method for the discovery of objects of interest in large spectroscopic surveys
• Mira Variable Stars From LAMOST DR4 Data: Emission Features, Temperature Types, and Candidate Selection
• The Gaia-ESO Survey: Catalogue of H$\alpha$ emission stars
• Identification of new Classical Ae stars in the Galaxy using LAMOST DR5
• Variability survey in the CoRoT SRa01 field: Implications of eclipsing binary distribution on cluster formation in NGC 2264
• Discovery of 2716 hot emission-line stars from LAMOST DR5
• A catalogue of early-type emission-line stars and Hα line profiles from LAMOST DR2
• The GALAH survey: Characterization of emission-line stars with spectral modelling using autoencoders
• Variable Stars in Young Open Cluster NGC 2244
• S-type stars from LAMOST DR10: classification of intrinsic and extrinsic stars