RT journal article
T1 Gaia Data Release 3: Exploring and mapping the diffuse interstellar band at 862 nm
A1 Schultheis, M.
A1 Zhao, H.
A1 Zwitter, T.
A1 Marshall, D.J.
A1 Drimmel, R.
A1 Berihuete Macías, Ángel
A2 Estadística e Investigación Operativa
K1 ISM: lines and bands
K1 ISM: kinematics and dynamics
K1 dust, extinction
AB Context. Diffuse interstellar bands (DIBs) are common interstellar absorption features in spectroscopic observations but their origins remainunclear. 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 theunknown molecular species responsible for the most prominent DIB at 862 nm in the RVS passband, exploring the Galactic ISM within a fewkiloparsecs 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. Inaddition 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. Wecompare spatial distributions of the DIB carrier with interstellar reddening and find evidence that DIB carriers are present in a local bubble aroundthe Sun which contains nearly no dust. We characterised the DIB equivalent width with a local density of 0.19 ± 0.04 Å kpc−1and a scale height of98.60+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 determinethe rest-frame wavelength with unprecedented precision (λ0 = 8620.86 ±0.019 Å in air) and reveal a remarkable correspondence between the DIBvelocities 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.
PB EDP Sciences
SN 1432-0746
YR 2023
FD 2023
LK http://hdl.handle.net/10498/31694
UL http://hdl.handle.net/10498/31694
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 11-nov-2026