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Gaia Data Release 1: Pre-processing and source list creation

Fabricius, C. and Blagorodnova, N. (2016) Gaia Data Release 1: Pre-processing and source list creation. Astronomy and Astrophysics, 595 . Art. No. A3. ISSN 0004-6361. doi:10.1051/0004-6361/201628643.

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Context. The first data release from the Gaia mission contains accurate positions and magnitudes for more than a billion sources, and proper motions and parallaxes for the majority of the 2.5 million HIPPARCOS and Tycho-2 stars. Aims. We describe three essential elements of the initial data treatment leading to this catalogue: the image analysis, the construction of a source list, and the near real-time monitoring of the payload health. We also discuss some weak points that set limitations for the attainable precision at the present stage of the mission. Methods. Image parameters for point sources are derived from one-dimensional scans, using a maximum likelihood method, under the assumption of a line spread function constant in time, and a complete modelling of bias and background. These conditions are, however, not completely fulfilled. The Gaia source list is built starting from a large ground-based catalogue, but even so a significant number of new entries have been added, and a large number have been removed. The autonomous onboard star image detection will pick up many spurious images, especially around bright sources, and such unwanted detections must be identified. Another key step of the source list creation consists in arranging the more than 10^(10) individual detections in spatially isolated groups that can be analysed individually. Results. Complete software systems have been built for the Gaia initial data treatment, that manage approximately 50 million focal plane transits daily, giving transit times and fluxes for 500 million individual CCD images to the astrometric and photometric processing chains. The software also carries out a successful and detailed daily monitoring of Gaia health.

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Blagorodnova, N.0000-0003-0901-1606
Additional Information:© 2016 ESO. Article published by EDP Sciences. Received 5 April 2016; Accepted 23 May 2016; Published online 24 November 2016. This work has made use of data from the ESA space mission Gaia, processed by the Gaia Data Processing and Analysis Consortium (DPAC). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. The Gaia mission website is: The authors are members of the DPAC, and this work has been supported by the following funding agencies: MINECO (Spanish Ministry of Economy) – FEDER through grant ESP2013-48318-C2-1-R and ESP2014-55996-C2-1-R and MDM-2014-0369 of ICCUB (Unidad de Excelencia “María de Maeztu”); The Netherlands Research School for Astronomy (NOVA); the German Aerospace Agency DLR under grants 50QG0501, 50QG1401, 50QG0601, 50QG0901, and 50QG1402; the European Space Agency in the framework of the Gaia project; the Agenzia Spaziale Italiana (ASI) through grants ASI I/037/08/0, ASI I/058/10/0, ASI 2014-025-R.0, and ASI 2014-025-R.1.2015 and the Istituto Nazionale di AstroFisica (INAF); the United Kingdom Space Agency; Fundação para a Ciência e a Tecnologia through the contract Ciência2007 and project grant PTDC/CTE-SPA/118692/2010. The authors thankfully acknowledge the computer resources from MareNostrum, technical expertise and assistance provided by the Red Española de Supercomputación at the Barcelona Supercomputing Center, Centro Nacional de Supercomputación. We also acknowledge the computer resources and support of CSUC, Consorci de Serveis Universitaris de Catalunya. In addition to the authors of this work there are many other people who have made valuable contributions to the core processing but who have meanwhile moved on to other projects. Among these, we want to specifically mention Sebastian Els, John Hoar, Ralf Keil, Ralf Kohley, Belén López Martí, Alexandros Ouzounis, Davide Padeletti, Michael Perryman, Stefan Theil, Pau Vallès, and Floor van Leeuwen. We also wish to thank Jos de Bruijne for support since the early developments and Klaus Meisenheimer for organising observing time at Calar Alto for the Gaia Ecliptic Poles Catalogue. Finally, we thank the referee, Dr. Norbert Zacharias, for many constructive comments and suggestions to an earlier version of this paper.
Funding AgencyGrant Number
Ministerio de Economía, Industria y Competitividad (MINECO)UNSPECIFIED
Fondo Europeo de Desarrollo Regional (FEDER)ESP2013-48318-C2-1-R
Fondo Europeo de Desarrollo Regional (FEDER)ESP2014-55996-C2-1-R
Unidad de Excelencia “María de Maeztu”MDM-2014-0369
Nederlandse Onderzoekschool Voor Astronomie (NOVA)UNSPECIFIED
Deutsches Zentrum für Luft- und Raumfahrt (DLR)50QG0501
Deutsches Zentrum für Luft- und Raumfahrt (DLR)50QG1401
Deutsches Zentrum für Luft- und Raumfahrt (DLR)50QG0601
Deutsches Zentrum für Luft- und Raumfahrt (DLR)50QG0901
Deutsches Zentrum für Luft- und Raumfahrt (DLR)50QG1402
European Space Agency (ESA)UNSPECIFIED
Agenzia Spaziale Italiana (ASI)ASI I/037/08/0
Agenzia Spaziale Italiana (ASI)ASI I/058/10/0
Agenzia Spaziale Italiana (ASI)ASI 2014-025-R.0.
Agenzia Spaziale Italiana (ASI)ASI 2014-025-R.1.2015
Istituto Nazionale di AstroFisica (INAF)UNSPECIFIED
United Kingdom Space Agency (UKSA)UNSPECIFIED
Fundação para a Ciência e a Tecnologia (FCT)Ciência2007
Fundação para a Ciência e a Tecnologia (FCT)PTDC/CTE-SPA/118692/2010
Subject Keywords:astrometry – methods: data analysis – space vehicles: instruments
Record Number:CaltechAUTHORS:20170111-160137693
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Official Citation:Gaia Data Release 1 - Pre-processing and source list creation C. Fabricius, U. Bastian, J. Portell, J. Castañeda, M. Davidson, N. C. Hambly, M. Clotet, M. Biermann, A. Mora, D. Busonero, A. Riva, A. G. A. Brown, R. Smart, U. Lammers, J. Torra, R. Drimmel, G. Gracia, W. Löffler, A. Spagna, L. Lindegren, S. Klioner, A. Andrei, N. Bach, L. Bramante, T. Brüsemeister, G. Busso, J. M. Carrasco, M. Gai, N. Garralda, J. J. González-Vidal, R. Guerra, M. Hauser, S. Jordan, C. Jordi, H. Lenhardt, F. Mignard, R. Messineo, A. Mulone, I. Serraller, U. Stampa, P. Tanga, A. van Elteren, W. van Reeven, H. Voss, U. Abbas, W. Allasia, M. Altmann, S. Anton, C. Barache, U. Becciani, J. Berthier, L. Bianchi, A. Bombrun, S. Bouquillon, G. Bourda, B. Bucciarelli, A. Butkevich, R. Buzzi, R. Cancelliere, T. Carlucci, P. Charlot, R. Collins, G. Comoretto, N. Cross, M. Crosta, F. de Felice, A. Fienga, F. Figueras, E. Fraile, R. Geyer, J. Hernandez, D. Hobbs, W. Hofmann, S. Liao, E. Licata, M. Martino, P. J. McMillan, D. Michalik, R. Morbidelli, P. Parsons, M. Pecoraro, M. Ramos-Lerate, M. Sarasso, H. Siddiqui, I. Steele, H. Steidelmüller, F. Taris, A. Vecchiato, A. Abreu, E. Anglada, S. Boudreault, M. Cropper, B. Holl, N. Cheek, C. Crowley, J. M. Fleitas, A. Hutton, J. Osinde, N. Rowell, E. Salguero, E. Utrilla, N. Blagorodnova, M. Soffel, J. Osorio, D. Vicente, J. Cambras and H.-H. Bernstein A&A, 595 (2016) A3 DOI:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:73456
Deposited By: Tony Diaz
Deposited On:18 Jan 2017 19:06
Last Modified:11 Nov 2021 05:16

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