Speaker
Description
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 $\sim430$ arcmin$^2$. This is $\sim2.5$ times larger than the area covered by previous UV data combined, reaching a depth of 27 ABmag. We present a robust 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 in the signal-to-noise ratios in our F275W imaging. Using well tested photometric redshift measurements and signal-to-noise ratio cut, we identify in total $5,810$ galaxy candidates at redshift range of $0.6 < z < 1$, down to $M_{UV} = -14.3 $. We restrict our analysis to sources with above $30\%$ completeness, in order to minimize the effect of uncertainties in estimating the completeness function especially at the faint-end. An unbiased maximum likelihood estimate is then performed on the unbinned data to derive the best-fit Schechter parameters of UV LF. We report a best-fit faint-end slope of $\alpha = -1.285^{+0.043}_{-0.042}$ at $z \sim 0.8$. By splitting our total sample to sub-samples at $z\sim0.7$ and $z\sim0.9$, respectively, we give a hint to the evolution behavior of $\alpha$ with redshift. The unobscured UV luminosity density at $M_\text{UV}<-10$ is derived as $\rho_\text{UV}=1.24^{+0.25}_{-0.25}\ (\times10^{26} \text{ergs/s/Hz/Mpc}^3)$ using our best-fit LF parameters.
