Modeling and Calibration of Gaia, Hipparcos, and Tycho-2 astrometric data for the detection of dark companions (2402.04919v1)

Abstract: Hidden within the Gaia satellite's multiple data releases lies a valuable cache of dark companions. To facilitate the efficient and reliable detection of these companions via combined analyses involving Gaia, Hipparcos, and Tycho-2 catalogs, we introduce an astrometric modeling framework. This method incorporates analytical least square minimization and nonlinear parameter optimization techniques to a set of common calibration sources across the different space-based astrometric catalogues. This enables us to discern the error inflation, astrometric jitter, differential parallax zero-point, and frame rotation of various catalogues relative to Gaia DR3. Our findings yield the most precise Gaia DR2 calibration parameters to date, revealing notable dependencies on magnitude and color. Intriguingly, we identify sub-mas frame rotation between Gaia DR1 and DR3, along with an estimated astrometric jitter of 2.16 mas for the revised Hipparcos catalog. In a thorough comparative analysis with previous studies, we offer recommendations on calibrating and utilizing different catalogs for companion detection. Furthermore, we provide a user-friendly pipeline (https://github.com/ruiyicheng/Download_HIP_Gaia_GOST) for catalog download and bias correction, enhancing accessibility and usability within the scientific community.