@article{cdf831a7fbd14a4e9dc6087db323e9e5,
title = "Gaia Data Release 3. Exploring and mapping the diffuse interstellar band at 862 nm",
abstract = "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. 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. 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. 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 Angstr{\"o}m/kpc and a scale height of 98.60+11.10−8.46 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 (λ0=8620.86±0.019 Angstr{\"o}m 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.",
keywords = "Dust, extinction, ISM: kinematics and dynamics, ISM: lines and bands",
author = "{Gaia Collaboration} and M. Schultheis and H. Zhao and T. Zwitter and Marshall, {D. J.} and R. Drimmel and Y. Fr{\'e}mat and Bailer-Jones, {C. A. L.} and A. Recio-Blanco and G. Kordopatis and Laverny, {P. de} and R. Andrae and Dharmawardena, {T. E.} and M. Fouesneau and R. Sordo and M. Davidson and Hambly, {N. C.} and Mann, {R. G.} and D. Morris and N. Rowell and S. Voutsinas",
note = "This is a Gaia Performance Verification Paper accepted for publication in A&A. The full author list is in the paper Funding Information: This work presents results from the European Space Agency (ESA) space mission Gaia. Gaia data are being processed by the Gaia Data Processing and Analysis Consortium (DPAC). Funding for the DPAC is provided by national institutions, in particular the institutions participating in the Gaia MultiLateral Agreement (MLA). The Gaia mission website is https://www.cosmos.esa.int/gaia. The Gaia archive website is https://archives.esac.esa.int/gaia. Full acknowledgements are given in Appendix A. T.Z. acknowledges financial support of the Slovenian Research Agency (research core funding No. P1-0188) and the European Space Agency (Prodex Experiment Arrangement No. C4000127986). Part of the calculations have been performed with the high-performance computing facility SIGAMM, hosted by the Observatoire de la C{\^o}te d{\textquoteright}Azur. The GSP-spec group acknowledges financial supports from the french space agency (CNES), Agence National de la Recherche (ANR 14-CE33-014-01) and Programmes Nationaux de Physique Stellaire & Cosmologie et Galaxies (PNPS & PNCG) of CNRS/INSU. H.Z. is funded by the China Scholarship Council (No.201806040200). Y.F. acknowledges the BELgian federal Science Policy Office (BELSPO) through various PROgramme de D{\'e}veloppement d{\textquoteright}Exp{\'e}riences scientifiques (PRODEX) grants. Publisher Copyright: {\textcopyright} 2023 The Authors.",
year = "2023",
month = jun,
day = "16",
doi = "10.1051/0004-6361/202243283",
language = "English",
volume = "674",
pages = "1--25",
journal = "Astronomy and Astrophysics",
issn = "0004-6361",
publisher = "EDP Sciences",
}