Gaia Data Release 3

, M. Schultheis, H. Zhao, T. Zwitter, D. J. Marshall, R. Drimmel, Y. Frémat, C. A.L. Bailer-Jones, A. Recio-Blanco, G. Kordopatis, P. De Laverny, R. Andrae, T. E. Dharmawardena, M. Fouesneau, R. Sordo, A. G.A. Brown, A. Vallenari, T. Prusti, J. H.J. De Bruijne, F. Arenou, C. Babusiaux, M. Biermann, O. L. Creevey, C. Ducourant, D. W. Evans, L. Eyer, R. Guerra, A. Hutton, C. Jordi, S. A. Klioner, U. L. Lammers, L. Lindegren, X. Luri, F. Mignard, C. Panem, D. Pourbaix, S. Randich, P. Sartoretti, C. Soubiran, P. Tanga, N. A. Walton, U. Bastian, F. Jansen, D. Katz, M. G. Lattanzi, F. Van Leeuwen, J. Bakker, C. Cacciari, J. Castañeda, J. Alves, T. Lebzelter

Context. Diffuse interstellar bands (DIBs) are common interstellar absorption features in spectroscopic observations but their origins remain unclear. DIBs play an important role in the life cycle of the interstellar medium (ISM) and can also be used to trace Galactic structure. Aims. Here, we demonstrate the capacity of the Gaia-Radial Velocity Spectrometer (RVS) in Gaia DR3 to reveal the spatial distribution of the unknown molecular species responsible for the most prominent DIB at 862 nm in the RVS passband, exploring the Galactic ISM within a few kiloparsecs from the Sun. Methods. The DIBs are measured within the GSP-Spec module using a Gaussian profile fit for cool stars and a Gaussian process for hot stars. In addition to the equivalent widths and their uncertainties, Gaia DR3 provides their characteristic central wavelength, width, and quality flags. Results. We present an extensive sample of 476 117 individual DIB measurements obtained in a homogeneous way covering the entire sky. We compare spatial distributions of the DIB carrier with interstellar reddening and find evidence that DIB carriers are present in a local bubble around the Sun which contains nearly no dust. We characterised the DIB equivalent width with a local density of 0.19 ± 0.04 kpc1 and a scale height of 98.60 8.46+11.10 pc. The latter is smaller than the dust scale height, indicating that DIBs are more concentrated towards the Galactic plane. We determine the rest-frame wavelength with unprecedented precision (?0 = 8620.86 ± 0.019 in air) and reveal a remarkable correspondence between the DIB velocities and the CO gas velocities, suggesting that the 862 nm DIB carrier is related to macro-molecules. Conclusions. We demonstrate the unique capacity of Gaia to trace the spatial structure of the Galactic ISM using the 862 nm DIB.

Department of Astrophysics
External organisation(s)
Université Côte d'Azur, University of Ljubljana, University of Toulouse, INAF-Osservatorio Astrofisico di Torino, Royal Observatory of Belgium, Max-Planck-Institut für Astronomie, Osservatorio Astronomico, Leiden University, Science and Operations Department - Science Division (SCI-SC), Paris Observatory, University of Grenoble Alpes, Scientific Software Center, Laboratoire d'Astrophysique de Bordeaux, University of Cambridge, Université de Genève, European Space Astronomy Centre (ESA), Universitat de Barcelona, Technische Universität Dresden, Lund Observatory, Centre national d'études spatiales (CNES), Université Libre de Bruxelles, Fonds de la Recherche Scientifique – FNRS, INAF - Osservatorio Astrofisico di Arcetri, Università degli Studi di Torino, Instituto Nazionale die Astrofisica (INAF)
Astronomy and Astrophysics
No. of pages
Publication date
Peer reviewed
Austrian Fields of Science 2012
103003 Astronomy, 103004 Astrophysics
ASJC Scopus subject areas
Astronomy and Astrophysics, Space and Planetary Science
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