Completeness of the Gaia-verse IV: The Astrometry Spread Function of Gaia DR2
| العنوان: | Completeness of the Gaia-verse IV: The Astrometry Spread Function of Gaia DR2 |
|---|---|
| المؤلفون: | Leigh C. Smith, Douglas Boubert, Andrew Everall, B. Holl, Sergey E. Koposov |
| المصدر: | Everall, A, Boubert, D, Koposov, S E, Smith, L & Holl, B 2021, ' Completeness of the Gaia-verse IV: The Astrometry Spread Function of Gaia DR2 ', Monthly Notices of the Royal Astronomical Society, vol. 502, no. 2, pp. 1908-1924 . https://doi.org/10.1093/mnras/stab041 |
| سنة النشر: | 2021 |
| مصطلحات موضوعية: | Physics, 010308 nuclear & particles physics, Point source, media_common.quotation_subject, Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Astrometry, Covariance, Gravitational microlensing, 01 natural sciences, Astrophysics - Astrophysics of Galaxies, Exoplanet, Apparent magnitude, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Sky, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Parallax, Astrophysics - Instrumentation and Methods for Astrophysics, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Solar and Stellar Astrophysics (astro-ph.SR), media_common |
| الوصف: | Gaia DR2 published positions, parallaxes and proper motions for an unprecedented 1,331,909,727 sources, revolutionising the field of Galactic dynamics. We complement this data with the Astrometry Spread Function (ASF), the expected uncertainty in the measured positions, proper motions and parallax for a non-accelerating point source. The ASF is a Gaussian function for which we construct the 5D astrometric covariance matrix as a function of position on the sky and apparent magnitude using the Gaia DR2 scanning law and demonstrate excellent agreement with the observed data. This can be used to answer the question `What astrometric covariance would Gaia have published if my star was a non-accelerating point source?'. The ASF will enable characterisation of binary systems, exoplanet orbits, astrometric microlensing events and extended sources which add an excess astrometric noise to the expected astrometry uncertainty. By using the ASF to estimate the unit weight error (UWE) of Gaia DR2 sources, we demonstrate that the ASF indeed provides a direct probe of the excess source noise. We use the ASF to estimate the contribution to the selection function of the Gaia astrometric sample from a cut on astrometric_sigma5d_max showing high completeness for $G 17 pages, 18 figures, published in MNRAS |
| وصف الملف: | application/pdf |
| اللغة: | English |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::9938520f3ad7c985c0afbdc32bce71f1 https://www.pure.ed.ac.uk/ws/files/188895172/Gaia_Posterior_PSF.pdf |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi.dedup.....9938520f3ad7c985c0afbdc32bce71f1 |
| قاعدة البيانات: | OpenAIRE |
| الوصف غير متاح. |