naa a22 4500 510790526 CHVBK 20180411083318.0 cr unu---uuuuu 180411e20130201xx s 000 0 eng 10.1134/S1063773713020047 doi (NATIONALLICENCE)springer-10.1134/S1063773713020047 Gontcharov G. Pulkovo Astronomical Observatory, Russian Academy of Sciences, Pulkovskoe sh. 65, 196140, St. Petersburg, Russia aut Spatial variations of the extinction law in the galactic disk from infrared observations [Elektronische Daten] [G. Gontcharov] Infrared photometry in the J (1.2 µm), H (1.7 µm), Ks (2.2 µm) bands from the 2MASS catalogue and in the W1 (3.4 µm), W2 (4.6 µm), W3 (12 µm), W4 (22 µm) bands from the WISE catalogue is used to reveal the spatial variations of the interstellar extinction law in the infrared near the midplane of the Galaxy by the method of extrapolation of the extinction law applied to clump giants. The variations of the coefficients E(H − W1)/E(H − Ks), E(H − W2)/E(H − Ks), E(H − W3)/E(H − Ks), and E(H − W4)/E(H − Ks) along the line of sight in 2° × 2° squares of the sky centered at b = 0° and l = 20°, 30°, ..., 330°, 340° as well as in several 4° × 4° squares with |b| = 10° are considered. The results obtained here agree with those obtained by Zasowski et al. in 2009 using 2MASS and Spitzer-IRAC photometry for the same longitudes and similar photometric bands, confirming their main result: in the inner (relative to the Sun) Galactic disk, the fraction of fine dust increases with Galactocentric distance (or the mean dust grain size decreases). However, in the outer Galactic disk that was not considered by Zasowski et al., this trend is reversed: at the disk edge, the fraction of coarse dust is larger than that in the solar neighborhood. This general Galactic trend seems to be explained by the influence of the spiral pattern: its processes sort the dust by size and fragment it so that coarse and fine dust tend to accumulate, respectively, at the outer and inner (relative to the Galactic center) edges of the spiral arms. As a result, fine dust may exist only in the part of the Galactic disk far from both the Galactic center and the edge, while coarse dust dominates at the Galactic center, at the disk edge, and outside the disk. Pleiades Publishing, Ltd., 2013 interstellar dust grains nationallicence color-magnitude diagram nationallicence giant and subgiant stars nationallicence Astronomy Letters SP MAIK Nauka/Interperiodica 39/2(2013-02-01), 83-94 1063-7737 39:2<83 2013 39 11443 https://doi.org/10.1134/S1063773713020047 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1134/S1063773713020047 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Gontcharov G. Pulkovo Astronomical Observatory, Russian Academy of Sciences, Pulkovskoe sh. 65, 196140, St. Petersburg, Russia aut NATIONALLICENCE 773 0- Astronomy Letters SP MAIK Nauka/Interperiodica 39/2(2013-02-01), 83-94 1063-7737 39:2<83 2013 39 11443 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer