ALMA 26 Arcmin$^{2}$ Survey of GOODS-S at One-millimeter (ASAGAO): Average Morphology of High-$z$ Dusty Star-Forming Galaxies is an Exponential-Disk ($n \simeq 1$)

Autor: 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, Nagao, Tohru, Tanaka, Ichi, Ao, Yiping, Espada, Daniel, Umehata, Hideki, Taniguchi, Yoshiaki, Nakanishi, Kouichiro, Rujopakarn, Wiphu, Ivison, J., Wang, Wei-hao, Lee, Minju, Tadaki, Ken-ichi, Tamura, Yoichi, Dunlop, J. S.
Rok vydání: 2018
Předmět:
Druh dokumentu: Working Paper
DOI: 10.3847/1538-4357/aac6c4
Popis: We present morphological properties of dusty star-forming galaxies at z=1-3 determined with high-resolution (FWHM~0"19) Atacama Large Milllimeter/submilimeter Array (ALMA) 1-mm band maps of our ASAGAO survey covering a 26-arcmin^2 area in GOODS-S. In conjunction with the ALMA archival data, the present sample consists of 42 ALMA sources with a wide rest-frame far-infrared (FIR) luminosity L_FIR range of ~10^11-10^13 Lo. To obtain an average rest-frame 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 the dusty star-forming galaxies have the average FIR-wavelength Sersic index and effective radius of n_FIR=1.2+/-0.2 and R_e,FIR=1.0-1.3 kpc, respectively, additionally with a point source at the center, indicative of the existence of AGN. The average FIR profile agrees with a morphology of an exponential-disk clearly distinguished from a spheroidal profile (Sersic index of 4). We also examine the rest-frame optical Sersic index n_opt and effective radius R_e,opt with the deep Hubble Space Telescope (HST) images. Interestingly, we obtain n_opt=0.9+/-0.3 (~n_FIR) and R_e,opt=3.2+/-0.6 kpc (>R_e,FIR), suggesting that the FIR-emitting disk is embedded within a larger stellar disk. The rest-frame UV and FIR data of HST and ALMA provide us a radial surface density profile of the total star-formation rate (SFR), where the FIR SFR dominates over the UV SFR at the center. Under the simple assumption of a constant SFR, a compact stellar distribution found in z~1-2 compact quiescent galaxies (cQGs) is well reproduced, while a spheroidal stellar morphology of cQGs (n_opt=4) cannot, suggestive of other important mechanisms such as dynamical dissipation.
Comment: 13 pages, 6 figures, ApJ in press
Databáze: arXiv
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