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arXiv · 2207.11379

Early results from GLASS-JWST. XI: Stellar masses and mass-to-light ratio of z>7 galaxies

P. Santini·A. Fontana·M. Castellano·N. Leethochawalit·M. Trenti·T. Treu·D. Belfiori·S. Birrer·A. Bonchi·E. Merlin·C. Mason·T. Morishita·M. Nonino·D. Paris·G. Polenta·P. Rosati·L. Yang·M. Bradac·A. Calabrò·A. Dressler·K. Glazebrook·D. Marchesini·S. Mascia·T. Nanayakkara·L. Pentericci·G. Roberts-Borsani·C. Scarlata·B. Vulcani·Xin Wang
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Abstract

We exploit James Webb Space Telescope (JWST) NIRCam observations from the GLASS-JWST-Early Release Science program to investigate galaxy stellar masses at z>7. We first show that JWST observations reduce the uncertainties on the stellar mass by a factor of at least 5-10, when compared with the highest quality data sets available to date. We then study the UV mass-to-light ratio, finding that galaxies exhibit a two orders of magnitude range of M/L_UV values for a given luminosity, indicative of a broad variety of physical conditions and star formation histories. As a consequence, previous estimates of the cosmic star stellar mass density - based on an average correlation between UV luminosity and stellar mass - can be biased by as much as a factor of ~6. Our first exploration demonstrates that JWST represents a new era in our understanding of stellar masses at z>7, and therefore of the growth of galaxies prior to cosmic reionization.

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P. Santini, A. Fontana, M. Castellano, N. Leethochawalit, M. Trenti, T. Treu, D. Belfiori, S. Birrer, A. Bonchi, E. Merlin, C. Mason, T. Morishita, M. Nonino, D. Paris, G. Polenta, P. Rosati, L. Yang, M. Bradac, A. Calabrò, A. Dressler, K. Glazebrook, D. Marchesini, S. Mascia, T. Nanayakkara, L. Pentericci, G. Roberts-Borsani, C. Scarlata, B. Vulcani, Xin Wang. 2022-07-22. Early results from GLASS-JWST. XI: Stellar masses and mass-to-light ratio of z>7 galaxies. https://doi.org/10.3847/2041-8213%2Fac9586

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