Print Email Facebook Twitter Gaia Data Release 3 Title Gaia Data Release 3: Exploring and mapping the diffuse interstellar band at 862 nm Author Schultheis, M. (Université Côte d'Azur) Zhao, H. (Université Côte d'Azur) Zwitter, T. (University of Ljubljana) Hladczuk, N.A. (TU Delft Astrodynamics & Space Missions; European Space Astronomy Centre (ESAC)) Guerra, R. (European Space Astronomy Centre (ESAC)) Lammers, U. L. (European Space Astronomy Centre (ESAC)) Bakker, J. (European Space Astronomy Centre (ESAC)) Teodoro, P. de (European Space Astronomy Centre (ESAC)) García-Lario, P. (European Space Astronomy Centre (ESAC)) Date 2023 Abstract 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. To reference this document use: http://resolver.tudelft.nl/uuid:6490fe54-db21-47c2-b79a-4c960e6b7f1a DOI https://doi.org/10.1051/0004-6361/202243283 ISSN 0004-6361 Source Astronomy & Astrophysics, 674 Part of collection Institutional Repository Document type journal article Rights © 2023 M. Schultheis, H. Zhao, T. Zwitter, N.A. Hladczuk, R. Guerra, U. L. Lammers, J. Bakker, P. de Teodoro, P. García-Lario, More Authors Files PDF aa43283_22.pdf 13.6 MB Close viewer /islandora/object/uuid:6490fe54-db21-47c2-b79a-4c960e6b7f1a/datastream/OBJ/view