Solution to the Conflict between the Estimations of Resolved and Unresolved Galaxy Stellar Mass from the Perspective of JWST
Jie Song, Guanwen Fang, Zesen Lin, Yizhou Gu, Xu Kong
Abstract
Abstract By utilizing the spatially resolved photometry of galaxies at 0.2 < z < 3.0 in the CEERS field, we estimate the resolved and unresolved stellar mass via fitting of the spectral energy distribution (SED) to study the discrepancy between them. We first compare M * derived from photometry with and without the JWST wavelength coverage and find that M * can be overestimated by up to 0.2 dex when lacking rest-frame near-infrared (NIR) data. The SED fitting process tends to overestimate both stellar age and dust attenuation in the absence of rest-frame NIR data, consequently leading to a larger observed mass-to-light ratio and hence an elevated M * . With the inclusion of the JWST NIR photometry, we find no significant disparity between the estimates of resolved and unresolved stellar mass, providing a plausible solution to the conflict between them out to z ∼ 3. Further investigation demonstrates that reliable M * estimates can be obtained, regardless of whether they are derived from spatially resolved or spatially unresolved photometry, so long as the reddest filter included in the SED fitting has a rest-frame wavelength longer than 10000 Å.