The Gaia-ASAS-SN classical Cepheids sample: I. Sample Selection

Abstract

We present a well-defined and characterized all-sky sample of classical Cepheids in the Milky Way, obtained by combining two time-domain all-sky surveys: Gaia DR2 (Gaia Collaboration et al. 2018) and ASAS-SN (Shappee et al. 2014). We first use parallax and variability information from Gaia to select ~30,000 bright (G<17) Cepheid candidates with M_K<-1. We then analyze their ASAS-SN V-band lightcurves, determining periods, and classifying the lightcurves using their Fourier parameters. This results in ~1900 likely Galactic Cepheids, which we estimate to be >90% complete and pure within our adopted selection criteria. This is the largest all-sky sample of Milky Way Cepheids that has such a well-characterized selection function, needed for population modeling and for systematic spectroscopic follow-up foreseen with SDSS-V. About 130 of these Cepheids have not been documented in the literature even as possible candidates.

arXiv comment21 pages, 11 figures, 2 tables fully available in electronic form. Submitted to ApJ. Any comment is welcome

References in corpus (25)

• Astropy: A Community Python Package for Astronomy
• Gaia Data Release 2. Summary of the contents and survey properties
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• A method for optimal image subtraction
• The ASAS-SN Catalog of Variable Stars I: The Serendipitous Survey
• 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
• Periodograms for Multiband Astronomical Time Series
• The ASAS-SN Catalog of Variable Stars II: Uniform Classification of 412,000 Known Variables
• A three-dimensional map of the Milky Way using classical Cepheid variable stars
• An intuitive 3D map of the Galactic warp's precession traced by classical Cepheids
• A re-classification of Cepheids in the Gaia Data Release 2
• Light curve analysis of Variable stars using Fourier decomposition and Principal component analysis
• New NIR light-curve templates for classical Cepheids
• A lack of classical Cepheids in the inner part of the Galactic disk
• The VVV Survey reveals classical Cepheids tracing a young and thin stellar disk across the Galaxy's bulge
• The Clouds are breaking: tracing the Magellanic system with Gaia DR1 Mira variables
• Kinematics of classical Cepheids in the Nuclear Stellar Disk
• Into the Darkness: Classical and Type II Cepheids in the Zona Galactica Incognita
• First metallicity determination from Near-Infrared spectra for five obscured Cepheids discovered in the inner Disk
• Discovery of a Pair of Classical Cepheids in an Invisible Cluster Beyond the Galactic Bulge
• Impact of distance determinations on Galactic structure. I. Young and intermediate-age tracers
• New classical Cepheids in the inner part of the northern Galactic disk and their kinematics
• Additional Galactic Cepheids from the OGLE Survey
• New variable stars in the Galactic Bulge: I. The bright regime

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• The Eighteenth Data Release of the Sloan Digital Sky Surveys: Targeting and First Spectra from SDSS-V
• Gaia Data Release 3: Mapping the asymmetric disc of the Milky Way
• A twisted and precessing Cepheid warp in the outer Milky Way disc