Gaia Data Release 2: Specific characterisation and validation of all-sky Cepheids and RR Lyrae stars

• DOI: 10.48550/arxiv.1805.02079
• Publication Date: 2018-01-01
• Authors: G. Clementini; V. Ripepi; R. Molinaro; A. Garofalo; T. Muraveva; L. Rimoldini; L. P. Guy; G. Jévardat de Fo...; K. Nienartowicz; O. Marchal; M. Audard; B. Holl; S. Leccia; M. Marconi; I. Musella; N. Mowlavï; I. Lecœur-Taı̈bi; L. Eyer; J. De Ridder; S. Regibo; L. M. Sarro; L. Szabados; D. W. Evans; M. Riello
• Keywords: RR Lyrae variable

The Gaia second Data Release (DR2) presents a first mapping of full-sky RR Lyrae stars and Cepheids observed by the spacecraft during initial 22 months science operations. Specific Object Study (SOS) pipeline, developed to validate fully characterise (SOS Cep&RRL) Gaia, has been presented in documentation papers accompanying Release. Here we describe how SOS pipeline was modified allow for processing multiband (G, G_BP G_RP) time series photometry all-sky candidate variables produce specific results confirmed that are published DR2 catalogue. Cep&RRL uses tools such as period-amplitude period-luminosity relations G band. For analysis candidates also used based on G_RP photometry, period-Wesenheit relation (G,G_RP). Multiband characterisation 150,359 (9,575 classified 140,784 stars) distributed all over sky. sample includes 87 globular clusters 14 dwarf galaxies. To best our knowledge, 25 April 2018, variability 50,570 these sources (350 50,220 is not known literature, hence likely they new discoveries Gaia. An estimate interstellar absorption 54,272 fundamental-mode from G-band amplitude pulsation period. Metallicities derived Fourier parameters light curves released 64,932 3,738 classical with period shorter than 6.3 days.