ALMA 26 Arcmin(2) Survey of GOODS-S at One Millimeter (ASAGAO): Average Morphology of High-z Dusty Star-forming Galaxies in an Exponential Disk (n similar or equal to 1)

作者：Fujimoto, Seiji^*; Ouchi, Masami; Kohno, Kotaro; Yamaguchi, Yuki; Hatsukade, Bunyo; Ueda, Yoshihiro; Shibuya, Takatoshi; Inoue, Shigeki; Oogi, Taira; Toft, Sune; Gomez-Guijarro, Carlos; Wang, Tao; Espada, Daniel; Nagao, Tohru; Tanaka, Ichi; Ao, Yiping; Umehata, Hideki; Taniguchi, Yoshiaki; Nakanishi, Kouichiro; Rujopakarn, Wiphu; Ivison, R. J.; Wang, Wei-hao; Lee, Minju M.; Tadaki, Ken-ichi; Tamura, Yoichi; Dunlop, J. S.

来源：Astrophysical Journal, 2018, 861(1): 7.

DOI：10.3847/1538-4357/aac6c4

• galaxies: evolution
• galaxies: formation
• galaxies: high-redshift
• galaxies: starburst
• galaxies: star formation

We present morphological properties of dusty star-forming galaxies at z = 1-3 determined with the high-resolution (FWHM similar to 0.'' 19) Atacama Large Milllimeter/submillimeter Array (ALMA) 1 mm map of our ASAGAO survey covering a 26 arcmin(2) area in GOODS-S. In conjunction with the ALMA archival data, our sample consists of 45 ALMA sources with infrared luminosity (L-IR) range of similar to 10(11) - 10(13) L circle dot. To obtain an average rest-frame far-infrared (FIR) profile, we perform individual measurements and careful stacking of the ALMA sources using the uv-visibility method that includes positional-uncertainty and smoothing-effect evaluations through Monte Carlo simulations. We find that our sample has an average FIR-wavelength Sersic index and effective radius of n(FIR) = 1.2 +/- 0.2 and R-e,R- FIR = 1.0-1.3 kpc, respectively, additionally with a point-source component at the center, indicative of the existence of active galactic nuclei. The average FIR profile agrees with a morphology of an exponential disk clearly distinguished from a de Vaucouleurs spheroidal profile (Sersic index of 4). We also examine the rest-frame optical Sersic index n(opt) and effective radius R-e,R-opt with deep Hubble Space Telescope (HST) images. Interestingly, we obtain n(opt) = 0.9 +/- 0.3 (similar or equal to n(FIR)) and R-e,R-opt = 3.2 +/- 0.6 kpc (> R-e,R-FIR), suggesting that the dusty disk-like structure is embedded within a larger stellar disk. The rest-frame UV and FIR data of HST and ALMA provide us with a radial profile of the total star formation rate (SFR), where the infrared SFR dominates over the UV SFR at the center. Under the assumption of a constant SFR, a compact stellar distribution in z similar to 1-2 compact quiescent galaxies (cQGs) is well reproduced, while a spheroidal stellar morphology of cQGs (n(opt) = 4) is not, suggestive of other important mechanism(s) such as dynamical dissipation.

• 单位
  中国科学院; 中国科学院紫金山天文台; 中国科学院国家天文台; RIKEN