James Webb Space Telescope Feed Post

Harvard ADS: The galaxy UV luminosity function at z ≃ 11 from a suite of public JWST ERS, ERO and Cycle-1 programs

Paper abstract: We present a new determination of the evolving galaxy UV luminosity function (LF) over the redshift range 9.5 < z < 12.5 based on a wide-area (>250 arcmin²) data set of JWST NIRCam near-infrared imaging assembled from thirteen public JWST surveys. Our relatively large-area search allows us to uncover a sample of 61 robust z > 9.5 candidates detected at =8s, and hence place new constraints on the intermediate-to-bright end of the UV LF. When combined with our previous JWST+UltraVISTA results, this allows us to measure the form of the LF over a luminosity range corresponding to four magnitudes (M₁₅₀₀). At these early times we find that the galaxy UV LF is best described by a double power-law function, consistent with results obtained from recent ground-based and early JWST studies at similar redshifts. Our measurements provide further evidence for a relative lack of evolution at the bright-end of the UV LF at z = 9 - 11, but do favour a steep faint-end slope (a = -2). The luminosity-weighted integral of our evolving UV LF provides further evidence for a gradual, smooth (exponential) decline in co-moving star-formation rate density (?_SFR) at least out to z ? 12, with our determination of ?_SFR(z = 11) lying significantly above the predictions of many theoretical models of galaxy evolution.