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

TL;DR

This study assesses the reliability of color-color selection for quiescent galaxies by analyzing submillimeter and AGN properties, revealing about 10% contamination from dusty star-forming galaxies and a link between quenching and radio-mode AGN feedback.

Contribution

It provides a comprehensive evaluation of the robustness of NUV-r-J color selection against dusty galaxy contamination using multi-wavelength submillimeter and radio data.

Findings

Approximately 10% of color-selected QGs are contaminated by dusty star-forming galaxies.

Luminous and less-luminous dusty galaxies are spatially correlated with QGs at <60 kpc.

High QG fraction among radio AGNs at z<1.5 suggests a connection between quenching and AGN feedback.

Abstract

We examine the robustness of the color-color selection of quiescent galaxies (QGs) against contamination of dusty star-forming galaxies using the latest submillimeter data. We selected 18,304 QG candidates out to $z\sim$ 3 using the commonly adopted $NUV-r-J$ selection based on the high-quality multi-wavelength COSMOS2015 catalog. Using extremely deep 450 and 850 $\mu$m catalogs from the latest JCMT SCUBA-2 Large Programs, S2COSMOS, and STUDIES, as well as ALMA submillimeter, VLA 3 GHz, and $Spitzer$ MIPS 24 $\mu$m catalogs, we identified luminous dusty star-forming galaxies among the QG candidates. We also conducted stacking analyses in the SCUBA-2 450 and 850 $\mu$m images to look for less-luminous dusty galaxies among the QG candidates. By cross-matching to the 24 $\mu$m and 3 GHz data, we were able to identify a sub-group of "IR-radio-bright" QGs who possess a strong 450 and 850 $\mu$m stacking signal. The potential contamination of these luminous and less-luminous dusty galaxies accounts 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 $\lesssim60$ 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.