Coordination Unit 8


Gaia's coordination unit 8 explained


Gaia's data release 3 brings the classification and the physical characterization of the observed sources based on Gaia spectra. APSIS, a software developed by the Gaia Coordination Unit 8 is responsible for that. This video leads you through the different steps in the process and shows the many people involved in Gaia's Coordination Unit 8. Though many people are shown, the list of people shown is not complete. More people are active at the various locations.

Idea of R. Sordo, O. Creevey, M. Fouesneau and all of CU8 Text and voice: R. Sordo Editing: F. Di Giacomo Software: After Effects and Davinci Resolve Videos and images: ESA/Gaia/DPAC, Gaia/DPAC/CU8-CU6, Recio-Blanco and the GSP-Spec team, CNES/MARTIN Emmanuelle 2017, ESO, ESA Music: "Epic Movie" Soundbay.


Who is CU8?


DPAC Coordination Unit 8 (CU8) is responsible for delivering to the community a classification of the Gaia sources and their characterization, by deriving different astrophysical parameters according to their nature. CU8 developed Apsis, a coherent series of modules aiming to tackle the problem using different approaches, from general to tailored to specific sources or parameters. Apsis results are published for the first time in Gaia DR3.

The video presents the general workflow of the analysis performed by Apsis modules, but most importantly it shows the persons behind the products, who devised and coded the algorithms, tested and validated their output, and collaborated for many years to improve the quality and the usability of the data in Gaia DR3.

Here is the list of people involved, per module and per working place. A number after a name indicates that their photo appears in the figure below (screenshot from the video), and allows matching of name and photo. Some CU8 members prefer not to appear on social media, but their names are included in the list below.


Management: O. Creevey - CU8 lead (29), M. Fouesneau (40), C.A.L. Bailer-Jones(18), Y. Fremat (37), U. Heiter (55), R. Sordo (17), F. Thevenin (13), F. Pailler (20)

DPCC-Toulouse: C.l. Panem (28), C. Nicolas, F. Pailler (20), A. Magdaleno Romeo (32), C. Robin, C. Nicolas, C. Fouron (45)

DSC -Heidelberg: C.A.L. Bailer-Jones(18), M. Fouesneau (40), R. Andrae (33)

GSPphot - Heidelberg: R. Andrae (33),  C.A.L. Bailer-Jones(18), M. Fouesneau (40), T. Dharmawardena (39)

GSPspec - Nice: A. Recio-Blanco (19), P. de Laverny (26), G. Kordopatis (4), C. Ordenovic (53), M. Schultheis (57), P.A. Palicio (51), G. Contursi (6), H. Zhao (41), E. Poggio (3)

GSPspec - A Coruña: M. Manteiga (25), G. Torralba Elipe (44), R. Santoveña, M. González

ESP-HS & ESP-ELS - Brussels: Y. Fremat (37), A. Lobel (48)

ESP-HS & ESP-ELS - Paris: J. Zorec (15)

ESP-CS - Catania: A. Lanzafame (8), E. Brugaletta (7)

ESP-UCD - Madrid: L. Sarro Baro (2)

ESP-UCD - St. Albans: W. Cooper (47)

ESP-UCD - Turin: R. Smart (14)

ESP-UCD - Sevilla: M. García Torres (5)

MSC - Heidelberg: J. Rybizki (46), R. Andrae (33), C.A.L. Bailer-Jones (18)

FLAME - Nice: O. Creevey (29), C. Ordenovic (53), F. Thevenin (13), Y. Lebreton (56), B. Pichon (12)

TGE - Turin: R. Drimmel (35), D. Licata

TGE - Toulouse: D. Marshall (38)

TGE - Copenhagen: J. Lindstrøm (54)

QSOC - Liège: L. Delchambre (49)

UGC - Athens: D. Hatzidimitriou (11), I Bellas-Velidis (9), M. Kontizas (10), E. Livanou (34)

OA - A Coruña: M. Manteiga (25), C. Dafonte (43), L. Pallas-Quintela (1), D. Garabato, A. Gómez

Validation DataBase - Madrid: A. Lorca (22), E. Utrilla (21), P. García Lario (23), A. Abreu, J. Bakker

Validation DataBase - Nice: I. Slezak (30), O. Creevey (29)

Validation DataBase - Heidelberg: M. Fouesneau (40)

Validation DataBase - Liège: L. Delchambre (49)

Validation DataBase - Uppsala: U. Heiter (55)

Simulations - Padova: R. Sordo (17), A. Vallenari (31)

Training data + Validation + Documentation: all previously mentioned plus A. Ulla (Vigo, 24), C. Soubiran (Bordeaux, 27), N. Brouillet (Bordeaux, 43), R. Carballo (Santander, 16), L. Casamiquela (Bordeaux, 50), B. Edvardsson (Uppsala, 36), A. Chiavassa (Nice)



Credits: ESA/Gaia/DPAC, F. Di Giacomo, R. Sordo, O. Creevey, M. Fouesneau, T. Roegiers + all CU8

Published 13 June 2022


Coordination Unit 8 - Pills of science


Introduction - R. Sordo


Mass - O. Creevey

Video on mass inference in Gaia's Coordination Unit 8 - O. Creevey - Pills of Science by CU8 experts. Video copyright: Gaia/DPAC/CU8/Orlagh Creevey. Video credits: ESA/Gaia/DPAC/CU8, O. Creevey, Video editing by R. Sordo, Intro segment by F. Di Giacomo, Based on the article Gaia Collaboration, Creevey, et al. 2022


Ultra-Cool Dwarfs - R. Smart

Video: Gaia and thee Unseen - R. Smart - Pills of Science by CU8 experts. Credits: Gaia/DPAC/CU8, Artist's renditions of Sun - Jupiter: from original by Dr. R. Hurt of the Infrared Processing and Analysis Center, Caltech, California USA; PanSTARRS DR1 r: R. White (STScI) and the PS1 Science Consortium; UKIDSS LAS J1: Produced as part of the The UKIRT Infrared Deep Sky Survey - Lawrence et al., 2007, MNRAS, 379, 1599.; Based on the article Gaia Collaboration, Creevey, O.L., et al. “Gaia Data Release 3: Golden Sample of Astrophysical Parameters”


Diffuse Interstellar Bands - M. Schultheis

Video on Gaia and the diffuse interstellar bands (DIBs) - M. Schultheis - Pills of Science by CU8 experts. Video copyright: Gaia/DPAC/CU8/Mathias Schultheis. Video credits: ESA/Gaia/DPAC/CU8, M. Schultheis, Animation: Z. He and M.Schultheis, Video editing by R. Sordo, Intro segment by F. Di Giacomo, Based on the article Gaia Collaboration, Schultheis, M., et al. “Gaia Data Release 3: Exploring and mapping the diffuse interstellar bands at 862nm”


What are stars made of - A. Recio-Blanco

Video on "What stars are made of?" - Alejandra Recio-Blanco - Pills of Science by Gaia DPAC CU8 experts. Credits: RVS Spectrum animation: ESA/Gaia/DPAC/CU8-CU6, A. Recio-Blanco and the GSPspec team; Chemical cartography video: ESA/Gaia/DPAC, S. Jordan, T. Sagristà, A. Recio-Blanco, P. A. Palicio, P. de Laverny, P. McMillan; Based on the article Gaia Collaboration, Recio-Blanco et al 2022, A&A, "Gaia Data Release 3: Chemical cartography of the Milky Way".



Credits: ESA/Gaia/DPAC/CU8

Published: 22 March 2023