@techreport{oai:jaxa.repo.nii.ac.jp:00001838,
 author = {松田, 桂子 and 堂谷, 忠靖 and Gandhi, Poshak and 中川, 貴雄 and 塩谷, 圭吾 and 松原, 英雄 and 瀧田, 怜 and 鳥羽, 儀樹 and Matsuta, Keiko and Dotani, Tadayasu and Gandhi, Poshak and Nakagawa, Takao and Enya, Keigo and Matsuhara, Hideo and Takita, Satoshi and Toba, Yoshiki},
 month = {Feb},
 note = {We studied mid-infrared (mid-IR) variability of AGN systematically combining two all-sky survey catalogs released by AKARI and Wide-field Infrared Survey Explorer (WISE). Because the two surveys are separated by approximately 4 years, our studies are sensitive to variations of time scales of a few years. We started with the list of AGN selected by Matsuta et al. (2012) from the cross-identification of Swift/BAT and AKARI catalogs. The list was further correlated with the WISE catalog to select a total of 71 AGN, which were used for the present studies. We compared source fluxes in the AKARI S9W (9μm) and WISE W3 (12μm) bands and in the AKARI L18W (18μm) and WISE W4 (22μm) bands carefully correcting for the band differences and considering the systematic effects. We detected significant flux changes from 3 sources, two blazars (3C 273, 3C 345) and a radio galaxy (3C 445), in the mid-IR bands. This is the first detection of mid-IR variability from 3C 445, which may be originated from the jets. We also analyzed average sample variability for different AGN types excluding these 3 variable sources. We detected significant variations from Seyfert 1 in the S9W-W3 band with 95% confidence limit; the average fractional variability reached 13% (6-18%). Two origins are conceivable for the variability: the dusty torus and the jets. If such variability originates from the torus, the dust distribution in the torus should be very narrow, and its radial extent may be much smaller than the distance to the AGN. Alternatively, the variability may result from the jets considered to be present in Seyfert 1 galaxies., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: AA1630016000, レポート番号: JAXA-RR-16-010E},
 title = {MID-INFRARED VARIABILITY OF ACTIVE GALACTIC NUCLEI WITH THE AKARI AND WISE ALL-SKY SURVEYS},
 year = {2017}
}