Udalski et al., 2016, Gaia and Variable Stars

# 세줄 요약 #

1. We present a comparison of the Gaia DR1 samples of pulsating variable stars with the OGLE Collection of Variable Stars aiming at the characterization of the Gaia mission performance in the stellar variability domain.
2. Out of 575 Cepheids and 2322 RR Lyrae candidates from the Gaia DR1 samples located in the OGLE footprint in the sky, 559 Cepheids and 2302 RR Lyrae stars are genuine pulsators of these types.
3. The completeness of the Gaia DR1 samples of Cepheids and RR Lyrae stars is at the level of 60–75% as compared to the OGLE Collection dataset.

 

# 상세 리뷰 #

1. Gaia & OGLE comparison

• Gaia EPSL (Ecliptic Pole Scanning Law): outskirts of LMC, Gaia DR1 Samples
• OGLE (Optical Gravitational Lensing Experiments): OGLE survey (OGLE-IV) (90% completeness)

 

2. Cepheids & RR Lyrae classification

• OGLE-IV 32-CCD Mosaic Camera
  • The technical gap between detectors
  • dead area: 7% -> dead zone
• Cross-section: Gaia in OGLE-IV field
  • 5 LMC region in OGLE-IV

 

3.   Completeness

• Gaia DR1: 60~75% completeness
  • Cepheid: 575 -> 559
  • RR Lyrae: 2322 -> 2302
• Problem:
  • mimic light curve of pulsating stars
  • fact spotted stars
  • ellipsoidal/eclipsing system
    • quasi-sinusoidal of light curve

 

* Reference: Udalski, A., “Gaia and Variable Stars”, <Acta Astronomica>, vol. 66, no. 4, pp. 433–453, 2016.