Revisiting the Color-Color Selection: Submillimeter and AGN Properties of NUV-r-J Selected Quiescent Galaxies

Abstract

We examine the robustness of the color-color selection of quiescent galaxies (QGs) against contamination of dusty star-forming galaxies using latest submillimeter data. We selected 18,304 QG candidates out to z ∼ 3 using the commonly adopted N U V -r-J selection based on the high-quality multi-wavelength COSMOS2015 catalog. Using extremely deep 450 and 850 µm catalogs from the latest JCMT SCUBA-2 Large Programs, S2COSMOS and STUDIES, as well as ALMA submillimeter, VLA 3 GHz, and Spitzer MIPS 24 µm catalogs, we identified luminous dusty star-forming galaxies among the QG candidates. We also conducted stacking analyses in the SCUBA-2 450 and 850 µm images to look for less-luminous dusty galaxies among the QG candidates. By cross-matching to the 24 µm and 3 GHz data, we were able to identify a sub-group of "IR-radio-bright" QGs who possess a strong 450 and 850 µm stacking signal. The potential contamination of these luminous and less-luminous dusty galaxies account for approximately 10% of the color-selected QG candidates. In addition, there exists a spatial correlation between the luminous star-forming galaxies and the QGs at a 60 kpc scale. Finally, we found a high QG fraction among radio AGNs at z < 1.5. Our data show a strong correlation between QGs and radio AGNs, which may suggest a connection between the quenching process and the radio-mode AGN feedback.