The Ultraviolet to Mid-infrared Extinction Law of the Taurus Molecular Cloud Based on the Gaia DR3, GALEX, APASS, Pan-STARRS1, 2MASS, and WISE Surveys

TL;DR

This study characterizes the ultraviolet to mid-infrared extinction law of the Taurus molecular cloud using data from multiple surveys, revealing limited regional variation and establishing a detailed wavelength-dependent extinction profile.

Contribution

It provides a comprehensive UV to IR extinction law for Taurus with improved wavelength resolution and assesses regional variations and the impact of Gaia Teff overestimation.

Findings

Derived UV--mid-IR color excess ratios for 16 bands.

Found average extinction law Rv=3.13+-0.32 with limited regional variation.

Confirmed negligible effect of Gaia Teff overestimation on results.

Abstract

Interstellar dust extinction law is essential for interpreting observations. In this work, we investigate the ultraviolet (UV)--mid-infrared (IR) extinction law of the Taurus molecular cloud and its possible variations. We select 504,988 dwarf stars (4200 K < Teff < 8000 K) and 4,757 giant stars (4200 K < Teff < 5200 K) based on the stellar parameters of Gaia DR3 as tracers. We establish the Teff--intrinsic color relations and determine the intrinsic color indices and color excesses for different types of stars. In the determination of color excess ratios (CERs), we analyze and correct the curvature of CERs and derive the UV--mid-IR CERs of 16 bands. We consider different effective wavelengths for different types of stars when converting CERs to relative extinction, and obtain the extinction law with a better wavelength resolution. In addition, we analyze the possible regional variation of extinction law and derive the average extinction law of Rv=3.13+-0.32 for the Taurus molecular cloud. Only 0.9% of subregions have deviations >3sigma, indicating limited regional variation in the extinction law. We also discuss the effect of Gaia Teff overestimation on the determination of the Taurus extinction law and find that the effect is negligible.