Three-dimensional extinction maps: Inverting inter-calibrated extinction catalogues

Context. Three-dimensional (3D) maps of the extinction density in Milky Way can be built through inversion large catalogues distance-extinction pairs for individual target stars. Considerable progress is currently achieved this field Gaia mission. Available are based on various types photometric or spectrophotometric information and different techniques estimations. Aims. The spatial resolution that increases with stars, and, consequently, combination input containing lists. However, requires careful inter-calibration catalogues. Our aim to develop methods inter-comparison two Methods. catalogue we used as reference a catalogue. It provides more accurate than purely In order reduce dimension problem, principal component analysis was performed ( G , B R J, H, K ) multi-colour space. subspace constituted by first components split into cells which estimated deviations from reference. were computed using all targets located at short distance each secondary target. Corrections filtering deduced cell Results. We applied very datasets: one hand, extinctions both spectroscopy photometry, representing 6 million objects serving reference, other 35 photometry eDR3 2MASS. After calibration, dispersion among neighbouring points second reduced, regardless whether present locally. Weak structures then apparent. high Galactic latitude significantly tightly correlated dust emission measured Planck property acquired A hierarchical technique merged inter-calibrated produce 3D corresponding volumes maximum resolution. 10 pc 3000 × 800 volume around Sun, size kpc 50 pc. inclusion spectroscopic survey data dynamic range density, improves accuracy maps, allows mapping extended greater distances better constrain remarkable ≃ 2.5 wide dust-free region quadrant particular, now appears giant oval superbubble. Maps downloaded means on-line tools.