3 research outputs found
Deep ugrizY imaging and DEEP2/3 spectroscopy: a photometric redshift testbed for LSST and public release of data from the DEEP3 Galaxy Redshift Survey
We present catalogues of calibrated photometry and spectroscopic redshifts in the Extended Groth Strip, intended for studies of photometric redshifts (photo-z’s). The data includes ugriz photometry from Canada–France–Hawaii Telescope Legacy Survey (CFHTLS) and Y-band photometry from the Subaru Suprime camera, as well as spectroscopic redshifts from the DEEP2, DEEP3, and 3D-HST surveys. These catalogues incorporate corrections to produce effectively matched-aperture photometry across all bands, based upon object size information available in the catalogue and Moffat profile point spread function fits. We test this catalogue with a simple machine learning-based photometric redshift algorithm based upon Random Forest regression, and find that the corrected aperture photometry leads to significant improvement in photo-z accuracy compared to the original SEXTRACTOR catalogues from CFHTLS and Subaru. The deep ugrizY photometry and spectroscopic redshifts are well suited for empirical tests of photometric redshift algorithms for LSST. The resulting catalogues are publicly available at http://d-scholarship.pitt.edu/36064/. We include a basic summary of the strategy of the DEEP3 Galaxy Redshift Survey to accompany the recent public release of DEEP3 data
The CANDELS/SHARDS multiwavelength catalog in GOODS-N : photometry, photometric redshifts, stellar masses, emission-line fluxes, and star formation rates
We present a WFC3 F160W (H-band) selected catalog in the CANDELS/GOODS-N field containing photometry from the ultraviolet (UV) to the far-infrared (IR), photometric redshifts, and stellar parameters derived from the analysis of the multiwavelength data. The catalog contains 35,445 sources over the 171 arcmin(2) of the CANDELS F160W mosaic. The 5 sigma detection limits (within an aperture of radius 0 ''.17) of the mosaic range between H = 27.8, 28.2, and 28.7 in the wide, intermediate, and deep regions, which span approximately 50%, 15%, and 35% of the total area. The multiwavelength photometry includes broadband data from the UV (U band from KPNO and LBC), optical (HST/ACS F435W, F606W, F775W, F814W, and F850LP), near-to-mid IR (HST/WFC3 F105W, F125W, F140W, and F160W; Subaru/MOIRCS Ks; CFHT/Megacam K; and Spitzer/IRAC 3.6, 4.5, 5.8, and 8.0 mu m), and far-IR (Spitzer/MIPS 24 mu m, HERSCHEL/PACS 100 and 160 mu m, SPIRE 250, 350 and 500 mu m) observations. In addition, the catalog also includes optical medium-band data (R similar to 50) in 25 consecutive bands, lambda = 500-950 nm, from the SHARDS survey and WFC3 IR spectroscopic observations with the G102 and G141 grisms (R similar to 210 and 130). The use of higher spectral resolution data to estimate photometric redshifts provides very high, and nearly uniform, precision from z = 0-2.5. The comparison to 1485 good-quality spectroscopic redshifts up to z similar to 3 yields Delta z/(1 + z(spec)) = 0.0032 and an outlier fraction of eta = 4.3%. In addition to the multiband photometry, we release value-added catalogs with emission-line fluxes, stellar masses, dust attenuations, UV- and IR-based star formation rates, and rest-frame colors
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Science Impacts of the SPHEREx All-Sky Optical to Near-Infrared Spectral Survey II: Report of a Community Workshop on the Scientific Synergies Between the SPHEREx Survey and Other Astronomy Observatories
SPHEREx is a proposed NASA MIDEX mission selected for Phase A study. SPHEREx
would carry out the first all-sky spectral survey in the near infrared. At the
end of its two-year mission, SPHEREx would obtain 0.75-to-5m spectra of
every 6.2 arcsec pixel on the sky, with spectral resolution R>35 and a
5- sensitivity AB>19 per spectral/spatial resolution element. More
details concerning SPHEREx are available at http://spherex.caltech.edu. The
SPHEREx team has proposed three specific science investigations to be carried
out with this unique data set: cosmic inflation, interstellar and circumstellar
ices, and the extra-galactic background light. Though these three themes are
undoubtedly compelling, they are far from exhausting the scientific output of
SPHEREx. Indeed, SPHEREx would create a unique all-sky spectral database
including spectra of very large numbers of astronomical and solar system
targets, including both extended and diffuse sources. These spectra would
enable a wide variety of investigations, and the SPHEREx team is dedicated to
making the data available to the community to enable these investigations,
which we refer to as Legacy Science. To that end, we have sponsored two
workshops for the general scientific community to identify the most interesting
Legacy Science themes and to ensure that the SPHEREx data products are
responsive to their needs. In February of 2016, some 50 scientists from all
fields met in Pasadena to develop these themes and to understand their
implications for the SPHEREx mission. The 2016 workshop highlighted many
synergies between SPHEREx and other contemporaneous astronomical missions,
facilities, and databases. Consequently, in January 2018 we convened a second
workshop at the Center for Astrophysics in Cambridge to focus specifically on
these synergies. This white paper reports on the results of the 2018 SPHEREx
workshop