AKARI observations of circumstellar dust in the globular clusters NGC 104 and NGC 362

作者：Ita Yoshifusa^*; Tanabe Toshihiko; Matsunaga Noriyuki; Nakada Yoshikazu; Matsuura Mikako; Onaka Takashi; Matsuhara Hideo; Wada Takehiko; Fujishiro Naofumi; Ishihara Daisuke; Kataza Hirokazu; Kim Woojung; Matsumoto Toshio; Murakami Hiroshi; Ohyama Youichi; Usui Fumihiko; Oyabu Shinki; Sakon Itsuki; Takagi Toshinobu; Uemizu Kazunori; Ueno Munetaka; Watarai Hidenori

来源：Publications of the Astronomical Society of Japan, 2007, 59: S437-S442.

• clusters : individual (NGC 104, NGC 362)
• Galaxy : globular
• infrared : stars
• stars : AGB and post-AGB

We report on preliminary results of AKARI observations of two globular clusters, NGC 104 and NGC 362. Imaging data covering areas of about 10 x 10 arcmin(2) centered on the two clusters were obtained with the Infrared Camera (IRC) at 2.4, 3.2, 4.1, 7.0, 9.0, 11.0, 15.0, 18.0, and 24.0 mu m. We used IRC 11.0 mu m to 2MASS K-s 2 mu m flux-density ratio (F-11/F-2) and IRC 24.0 mu m to 7.0 mu m flux-density ratio (F-24/F-7) as diagnostics of circumstellar dust emission. Dust emissions are mainly detected from variable stars, obviously on the asymptotic giant branch, but some variable stars that reside below the tip of the first-ascending giant branch also show dust emissions. We found eight red sources with the F-24/F-7 ratio being greater than unity in NGC 362. Six out of the eight have no 2MASS counterparts. However, we found no such source in NGC 104.

• 出版日期2007
• 单位中国科学院国家天文台