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arXiv · 0706.0045

AKARI observations of circumstellar dust in the globular clusters NGC104 and NGC362

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

We report preliminary results of AKARI observations of two globular clusters, NGC104 and NGC362. Imaging data covering areas of about 10x10 arcmin^2 centered on the two clusters have been obtained with InfraRed Camera (IRC) at 2.4, 3.2, 4.1, 7.0, 9.0, 11.0, 15.0, 18.0 and 24.0 mu. We used F11/F2 and F24/F7 flux ratios 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 F24/F7 ratio greater than unity in NGC362. Six out of the eight have no 2MASS counterparts. However, we found no such source in NGC104.

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Yoshifusa Ita, Toshihiko Tanabe, Noriyuki Matsunaga, Yoshikazu Nakada, Mikako Matsuura, Takashi Onaka, Hideo Matsuhara, Takehiko Wada, Naofumi Fujishiro, Daisuke Ishihara, Hirokazu Kataza, Woojung Kim, Toshio Matsumoto, Hiroshi Murakami, Youichi Ohyama, Fumihiko Usui, Shinki Oyabu, Itsuki Sakon, Toshinobu Takagi, Kazunori Uemizu, Munetaka Ueno, Hidenori Watarai. 2007-06-01. AKARI observations of circumstellar dust in the globular clusters NGC104 and NGC362. https://doi.org/10.1093/pasj%2F59.sp2.s437

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