Gaia

The Galactic Census
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Credit: ESA/ATG medialab; background image: ESO/S. Brunier

Gaia at the AIP

The ESA Satellite Gaia creates the most accurate map of the Milky Way. On December 3rd 2020, Gaia published 1.8 billion object positions, the largest astronomical catalogue so far. By precisely measuring positions and motions of the objects, Gaia helps answering questions about the origin and evolution of our home galaxy.

The AIP contributes to the effort of the Gaia Data Processing and Analysis Consortium (DPAC) with three different topics:

1.) Software Pipeline for Dense Regions in the Sky

Since 2014 Gaia observed nine selected very dense regions in the sky, so called crowded fields (CF), using the Service Interface Function (SIF) of the Gaia Sky Mapper (SM). In 2019 DPAC set up a new working group within Calibration Unit 3 "Core Processing" with the purpose of creating a new software pipeline to reduce these images. The aim is to extract astrometry and photometry for additional sources in these regions, in order to increase the completeness of the mentioned regions. The AIP is heavily involved in this effort, providing both the main software development and the management of the small DPAC group.

2.) Background Correction for Gaia's Spectra

More than any other Gaia instrument, the Radial Velocity Spectrometer (RVS) suffers from the higher than expected straylight that Gaia suffers. Since 2007, the RVS background correction is written and maintained at AIP, first calculating the correction of contaminating light from point sources, that can be fully modelled and subtracted from target spectra. After commissioning, the focus of our DPAC contribution shifted to the creation of straylight maps, that are used to estimate the background light from diffuse sources.

3.) Mirror of the Gaia Archive

The AIP is an official Gaia Partner Data Center and provides full data access to all official Gaia data releases of DPAC, that can be found on Gaia@AIP. Additionally, AIP provides a web interface to explore and visualize the data and a user space to store search results that can also be shared among user groups. It supports research groups of AIP with crossmatches of not yet published catalogs, and also of published catalogs from RAVE. The data publication includes the StarHorse catalog as part of the contributions to the Gaia data, and service tables, e.g. a Gaia source table with coordinates in the J2000 reference epoch.

Funding: DLR, 50QG1904

Last update: 16. June 2021