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arXiv · 2207.13101

Early results from GLASS-JWST. V: the first rest-frame optical size-luminosity relation of galaxies at $z>7$

Lilan Yang·T. Morishita·N. Leethochawalit·M. Castellano·A. Calabro·T. Treu·A. Bonchi·A. Fontana·C. Mason·E. Merlin·D. Paris·M. Trenti·G. Roberts-Borsani·M. Bradac·E. Vanzella·B. Vulcani·D. Marchesini·X. Ding·Themiya Nanayakkara·Simon Birrer·K. Glazebrook·T. Jones·K. Boyett·P. Santini·Victoria Strait·Xin Wang
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Abstract

We present the first rest-frame optical size-luminosity relation of galaxies at $z>7$, using the NIRCam imaging data obtained by the GLASS James Webb Space Telescope Early Release Science (GLASS-JWST-ERS) program, providing the deepest extragalactic data of the ERS campaign. Our sample consist of 19 photometrically selected bright galaxies with $m_\text{F444W}\leq27.8$ at $7 7$. Given the limited sample size and magnitude range, we first fix the slope to that observed for larger samples in rest-frame UV using HST samples. The median size $r_0$ at the reference luminosity $M=-21$ decreases slightly from rest-frame optical ($600\pm80$ pc) to UV ($450\pm130$ pc). We then re-fit the size-luminosity relation allowing the slope to vary. The slope is consistent with $\beta\sim0.2$ for all bands except F150W, where we find a marginally steeper slope of $\beta=0.53\pm0.15$. The steep UV slope is mainly driven by the smallest and faintest galaxies. If confirmed by larger samples, it implies that the UV size-luminosity relation breaks toward the faint end as suggested by lensing studies.

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Lilan Yang, T. Morishita, N. Leethochawalit, M. Castellano, A. Calabro, T. Treu, A. Bonchi, A. Fontana, C. Mason, E. Merlin, D. Paris, M. Trenti, G. Roberts-Borsani, M. Bradac, E. Vanzella, B. Vulcani, D. Marchesini, X. Ding, Themiya Nanayakkara, Simon Birrer, K. Glazebrook, T. Jones, K. Boyett, P. Santini, Victoria Strait, Xin Wang. 2022-07-26. Early results from GLASS-JWST. V: the first rest-frame optical size-luminosity relation of galaxies at $z>7$. https://doi.org/10.3847/2041-8213%2Fac8803

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