The UV luminosity function at 0.6 < z < 1 from UVCANDELS

Events Calendar

 Time:  Friday, December 1, 2023, 12:00pm
 Title:  The UV luminosity function at 0.6 < z < 1 from UVCANDELS
 Speaker:  Lei Sun (UCAS)
 Location:  S727


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 ~426 arcmin^2. This is ~2.7 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 1.5X 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_{UV} = -14.3. 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 4731 galaxies at -21.5<M_{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 = -1.286^{+0.043}_{-0.042} at  z~0.8. Creating sub-samples at z~0.7 and z~0.9, we observe a possible evolution of \alpha with redshift. The unobscured UV luminosity density at M_{UV}<-10 is derived as \rho_{UV}=1.309^{+0.24}_{-0.26}\ (X10^26 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).


2005-2010 PKU&Marseille University, France, PhD in astrophics;  

2010-2013  NAOC, postdoc; 

2013-2016 THU, postdoc; 

2023.2-now  UCAS, assistent research fellow