A PRECISE DETERMINATION OF THE MID-INFRARED INTERSTELLAR EXTINCTION LAW BASED ON THE APOGEE SPECTROSCOPIC SURVEY

作者：Xue, Mengyao^*; Jiang, B. W.; Gao, Jian; Liu, Jiaming; Wang, Shu; Li, Aigen

来源：Astrophysical Journal, The - Supplement Series, 2016, 224(2): 23.

DOI：10.3847/0067-0049/224/2/23

• dust, extinction
• galaxies: ISM
• Galaxy: disk
• infrared: ISM

A precise measure of the mid-infrared interstellar extinction law is crucial for investigating the properties of interstellar dust, especially larger-sized grains. Based on the stellar parameters derived from the SDSS-III/Apache Point Observatory Galaxy Evolution Experiment (APOGEE) spectroscopic survey, we select a large sample of G-type and K-type giants as the tracers of the Galactic mid-infrared extinction. We calculate the intrinsic stellar color excesses from the stellar effective temperatures and use them to determine the mid-infrared extinction for a given line of sight. For the entire sky of the Milky Way surveyed by APOGEE, we derive the extinctions (relative to AKS, the K-S-band extinction at wavelength lambda = 2.16 mu m) for the four Wide-field Infrared Survey Explorer (WISE) bands at 3.4, 4.6, 12, and 22 mu m, the four Spitzer/Infrared Array Camera bands at 3.6, 4.5, 5.8, and 8 mu m, the Spitzer/ MIPS24 band at 23.7 mu m, and, for the first time, the AKARI/S9W band at 8.23 mu m. Our results agree with previous works in that the extinction curve is flat in the similar to 3-8 mu m wavelength range and is generally consistent with the R-V = 5.5 model curve, except our determination exceeds the model prediction in the WISE/W4 band. Although some previous works found that the mid-IR extinction law appears to vary with the extinction depth A(KS), no noticeable variation has been found in this work. The uncertainties are analyzed in terms of the bootstrap resampling method and Monte-Carlo simulation and are found to be rather small.

• 出版日期2016-6
• 单位北京师范大学