The Optical to Infrared Extinction Law of Magellanic Clouds Based on Red Supergiant and Classical Cepheid

Abstract

Precise interstellar dust extinction laws are important to infer the intrinsic properties of reddened objects and correctly interpret observations. In this work, we attempt to measure the optical--infrared extinction laws of the Large and Small Magellanic Clouds (LMC and SMC) by using red supergiant (RSG) stars and classical Cepheids as extinction tracers. The spectroscopic RSG samples are constructed based on the APOGEE spectral parameters, Gaia astrometric data, and multi-band photometry. We establish the effective temperature--intrinsic color relations for RSG stars and determine the color excess ratio (CER) E(lambda-GRP)/E(GBP-GRP) for LMC and SMC. We use classical Cepheids to derive base relative extinction A_GRP/E(GBP-GRP). The results are 1.589+-0.014 and 1.412+-0.041 for LMC and SMC. By combining CERs with A_GRP /E(GBP-GRP), the optical--infrared extinction coefficients A_lambda/A_GRP are determined for 16 bands. We adjust the parameters of Rv-dependent extinction laws and obtain the average extinction law of LMC and SMC as Rv=3.40+-0.07 and Rv=2.53+-0.10, which are consistent with Gordon et al. (2003). In the optical bands, the adjusted Rv extinction curves agree with the observations with deviations less than 3%.

24 pages, 12 figures, 6 tables, Accepted for publication in ApJ

References in corpus (22)

• The 2.5 m Telescope of the Sloan Digital Sky Survey
• An Analysis of the Shapes of Interstellar Extinction Curves. V. The IR-Through-UV Curve Morphology
• The Optical to Mid-Infrared Extinction Law Based on the APOGEE, Gaia DR2, Pan-STARRS1, SDSS, APASS, 2MASS and WISE Surveys
• The Apache Point Observatory Galactic Evolution Experiment (APOGEE) Spectrographs
• An Analysis of the Shapes of Interstellar Extinction Curves. VII. Milky Way Spectrophotometric Optical-through-Ultraviolet Extinction and Its R-Dependence
• SkyMapper Southern Survey: Second Data Release (DR2)
• The Effective Temperatures and Physical Properties of Magellanic Cloud Red Supergiants: The Effects of Metallicity
• Variability in red supergiant stars: pulsations, long secondary periods and convection noise
• Spitzer SAGE-SMC Infrared Photometry of Massive Stars in the Small Magellanic Cloud
• The VLT-FLAMES Tarantula Survey XVI. The optical+NIR extinction laws in 30 Doradus and the photometric determination of the effective temperatures of OB stars
• Fundamental properties and atmospheric structure of the red supergiant VY CMa based on VLTI/AMBER spectro-interferometry
• Luminosities and mass-loss rates of Local Group AGB stars and Red Supergiants
• Red Supergiant Stars in the Large Magellanic Cloud: I. The Period-Luminosity Relation
• The VLT-FLAMES Tarantula Survey. XXX. Red stragglers in the clusters Hodge 301 and SL 639
• The period-luminosity relation of red supergiants with Gaia DR2
• Constraining Dust Extinction Properties via the VVV Survey
• The Second Data Release of the Survey of the MAgellanic Stellar History (SMASH)
• Variations of the Interstellar Extinction Law within the Nearest Kiloparsec
• Evolved Massive Stars at Low-metallicity III. A Source Catalog for the Large Magellanic Cloud
• Revision of Stellar Intrinsic Colors in the Infrared by the Spectroscopic Surveys
• The Optical -- Mid-infrared Extinction Law of the l=165 Sightline in the Galactic Plane: Diversity of Extinction Law in the Diffuse Interstellar Medium
• On Granulation and Irregular Variation of Red Supergiants