Three-dimensional Maps Of Interstellar Dust In The Local Arm.pdf

The study leverages the synergy between stellar calibrations and 3D mapping for a more detailed understanding of the Galactic ISM.

Key Points:

1. Data and Methodology:
- A previous map of nearby interstellar dust was used to select low-reddening red giants from the SDSS/APOGEE-DR14 survey.
- An empirical photometric calibration was developed for the Gaia G and 2MASS Ks bands, considering effective temperature and metallicity.
- This calibration was combined with Gaia's empirical extinction coefficients to derive extinctions for a large dataset of survey targets.

2. Map Update:
- Distances were estimated using isochrones and the magnitude-independent extinction KJ−Ks method.
- The new data was merged with previous maps, leading to an updated 3D dust map.

3. Map Properties and Findings:
- The map reveals detailed structures in the Local Arm, including chains of clouds aligned with a specific axis and cavities oriented along another.
- It confirms that large dust shells seen in emission at middle and high latitudes are closer than 300 pc.
- The North Polar Spur's origin is constrained to be beyond 800 pc.

4. Synergy with Gaia:
- The study illustrates the ongoing collaboration between 3D mapping of IS dust and stellar calibrations in the context of Gaia.
- Dust maps serve as prior foregrounds for future calibrations tailored to specific target characteristics, enhancing extinction data and map detail.