Hyung Mok Lee, Myungshin Im, Takehiko Wada, Hyunjin Shim, Seong Jin Kim, Myung Gyoon Lee, Narae Hwang, Hideo Matsuhara, Takao Nakagawa, Shinki Oyabu, Chris P. Pearson, Toshinobu Takagi, Takashi Onaka, Naofumi Fujishiro, Hitoshi Hanami, Daisuke Ishihara, Yoshifusa Ita, Hirokazu Kataza, Woojung Kim, Toshio Matusmoto, Hiroshi Murakami, Youichi Ohyama, Itsuki Sakon, Toshiko Tanabe, Kazunori Uemizu, Munetaka Ueno, Fumihiko Usui, Hidenori Watarai
2007年5月10日
We present the properties of 11 $\mu$m selected sources detected in the early
data of the North Ecliptic Pole Deep (NEP-Deep) Survey of AKARI. The data set
covers 6 wavelength bands from 2.5 to 11 $\mu$m, with the exposure time of 10 ~
20 minutes. This field lies within the CFHT survey with four filter bands ($g',
r', i',z'), enabling us to establish nearly continuous spectral energy
distributions (SEDs) for wavelengths ranging from 0.4 to 11 $\mu$m. The main
sample studied here consists of 71 sources whose 11 $\mu$m AB magnitudes are
equal to or brighter than 18.5 (251 $\mu$Jy), which is complete to more than
90%. The 11 $\mu$m band has an advantage of sampling star forming galaxies with
low to medium redshifts since the prominent PAH feature shifts into this band.
As expected, we find that the majority (~68%) of 11 $\mu$m bright sources are
star forming galaxies at 0.2 < z < 0.7 with $L_{IR} ~ 10^{10}$ -- $10^{12}
L_{\odot}$ based on the detailed modelling of SEDs. We also find four AGNs
lying at various redshifts in the main sample. In addition, we discuss a few
sources which have non-typical SEDs of the main sample, including a brown dwarf
candidate, a steep power-law source, flat spectrum object, and an early-type
galaxy at moderate redshift.