The galaxy UV luminosity function at $\mathbf{z}\simeq 11$ from a suite of public JWST ERS, ERO and Cycle-1 programs

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 ($>250$ arcmin${}^2$) 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 $\ge 8\ddot{I}ƒ$, 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 ($M_{1500}$). 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 ($\hat{I}\pm \le -2$). 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 ($\ddot{I}{}_{\mathrm{SFR}}$) at least out to $z\simeq 12$, with our determination of $\ddot{I}{}_{\mathrm{SFR}}(z=11)$ lying significantly above the predictions of many theoretical models of galaxy evolution.

20 pages, 9 figures, accepted for publication in MNRAS