摘要
We present ALMA Band 7 observations of a remarkably bright galaxy candidate atz_(\rm phot) = 16.7^(+1.9)_(-0.3)( M_(\rm UV) = -21.6 ), S5-z17-1, identified in JWST Early Release Observation data of Stephen's Quintet. We do not detect the dust continuum at 866 μ m, ruling out the possibility that \ {i}{s} a low- zdusty starburst with a star-formation rate of≳ 30 M_(⊙) yr ⁻¹ . We detect a 5.1 σline feature at338.726±0.007 GHz exactly coinciding with the JWST source position, with a 2% likelihood of the signal being spurious. The most likely line identification would be [OIII]52 μ m atz=16.01or [CII]158 μ m atz=4.61 , whose line luminosities do not violate the non-detection of the dust continuum in both cases. Together with three otherz≳11–13 candidate galaxies recently observed with ALMA, we conduct a joint ALMA and JWST spectral energy distribution (SED) analysis and find that the high- zsolution atz∼ 11–17 is favored in every candidate as a very blue (UV continuum slope of≃-2.3 ) and luminous ( M_(\rm UV)≃[- 24: -21] ) system. Still, we find in several candidates that reasonable SED fits ( Δχ²≲4 ) are reproduced by type-II quasar and/or quiescent galaxy templates with strong emission lines atz∼3 –5, where such populations predicted from their luminosity functions and EW([OIII]+H β ) distributions are abundant in survey volumes used for the identification of thez∼ 11–17 candidates. While these recent ALMA observation results have strengthened the likelihood of the high- zsolutions, lower- zpossibilities are not completely ruled out in several of thez∼ 11–17 candidates, indicating the need to consider the relative surface densities of the lower- zcontaminants in the ultra high- zgalaxy search.