摘要
UVCANDELS is a HST Cycle-26 Treasury Program awarded 164 orbits of primary ultraviolet (UV) F275W imaging and coordinated parallel optical F435W imaging in four CANDELS fields: GOODS-N, GOODS-S, EGS, and COSMOS, covering a total area of$\sim426$arcmin $^2$ . This is$\sim2.7$times larger than the area covered by previous deep-field space UV data combined, reaching a depth of about 27 and 28 ABmag ( $5\sigma$in$0.2"$apertures) for F275W and F435W, respectively. Along with the new photometric catalogs, we present an analysis of the rest-frame UV luminosity function (LF), relying on our UV-optimized aperture photometry method yielding a factor of$1.5\times$increase than the H-isophot aperture photometry in the signal-to-noise ratios of galaxies in our F275W imaging. Using well tested photometric redshift measurements we identify 5810 galaxies at redshifts$0.6<z<1$ , down to an absolute magnitude of$M_\text{UV} = -14.2$ . In order to minimize the effect of uncertainties in estimating the completeness function, especially at the faint-end, we restrict our analysis to sources above$30\%$completeness, which provides a final sample of 4726 galaxies at$-21.5<M_\text{UV}<-15.5$ . We performed a maximum likelihood estimate to derive the best-fit parameters of the UV LF. We report a best-fit faint-end slope of$\alpha = -1.359^{+0.041}_{-0.041}$at$z \sim 0.8$ . Creating sub-samples at$z\sim0.7$and$z\sim0.9$ , we observe a possible evolution of$\alpha$with redshift. The unobscured UV luminosity density at$M_\text{UV}<-10$is derived as$\rho_\text{UV}=1.339^{+0.027}_{-0.030}\ (\times10^{26} \text{ergs/s/Hz/Mpc}^3)$using our best-fit LF parameters. The new F275W and F435 photometric catalogs from UVCANDELS have been made publicly available on the Barbara A. Mikulski Archive for Space Telescopes (MAST).