An Empirical Extinction Curve Revealed by Gaia XP Spectra and LAMOST
Abstract
We present a direct measurement of extinction curves using corrected Gaia XP spectra of the common sources in Gaia DR3 and LAMOST DR7. Our analysis of approximately 370,000 high-quality samples yielded a high-precision average extinction curve for the Milky Way. After incorporating infrared photometric data from Two Micron All Sky Survey and Wide-field Infrared Survey Explorer, the extinction curve spans wavelengths from 0.336 to 4.6 μm. We determine an average R 55 of 2.730 ± 0.007, corresponding to R V = 3.073 ± 0.009, and a near-infrared power-law index α of 1.935 ± 0.037. Our study confirmed some intermediate-scale structures within the optical range. One new feature was identified at 540 nm, and its intensity exhibited a correlation with extinction. This extinction curve can be used to investigate the characteristics of dust and enhance the extinction correction of Milky Way stars. A Python package for this extinction curve is available.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 2024
- DOI:
- 10.3847/1538-4357/ad613e
- arXiv:
- arXiv:2407.12386
- Bibcode:
- 2024ApJ...971..127Z
- Keywords:
-
- Interstellar dust extinction;
- Interstellar dust;
- Interstellar extinction;
- Interstellar reddening;
- Astrosphere interstellar medium interactions;
- Reddening law;
- Milky Way Galaxy;
- Spectroscopy;
- Photometry;
- 837;
- 836;
- 841;
- 853;
- 106;
- 1377;
- 1054;
- 1558;
- 1234;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 11 pages, 5 figures, accepted for publication in ApJ