CANDELS: THE COSMIC ASSEMBLY NEAR-INFRARED DEEP EXTRAGALACTIC LEGACY SURVEY—THE HUBBLE SPACE TELESCOPE OBSERVATIONS, IMAGING DATA PRODUCTS, AND MOSAICS

Abstract

This paper describes the Hubble Space Telescope imaging data products and data reduction procedures for the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS). This survey is designed to document the evolution of galaxies and black holes at z ∼ 1.5 − 8, and to study Type Ia SNe beyond z > 1.5. Five premier multi-wavelength sky regions are selected, each with extensive multiwavelength observations. The primary CANDELS data consist of imaging obtained in the Wide Field Camera 3 / infrared channel (WFC3/IR) and UVIS channel, along with the Advanced Camera for Surveys (ACS). The CANDELS/Deep survey covers ∼ 125 square arcminutes within GOODS-N and GOODS-S, while the remainder consists of the CANDELS/Wide survey, achieving a total of ∼ 800 square arcminutes across GOODS and three additional fields (EGS, COSMOS, and UDS). We summarize the observational aspects of the survey as motivated by the scientific goals and present a detailed description of the data reduction procedures and products from the survey. Our data reduction methods utilize the most up to date calibration files and image combination procedures. We have paid special attention to correcting a range of instrumental effects, including CTE degradation for ACS, removal of electronic bias-striping present in ACS data after SM4, and persistence effects and other artifacts in WFC3/IR. For each field, we release mosaics for individual epochs and eventual mosaics containing data from all epochs combined, to facilitate photometric variability studies and the deepest possible photometry. A more detailed overview of the science goals and observational design of the survey are presented in a companion paper.

Isotropic at the Break? 3d Kinematics of Milky Way Halo Stars in the Foreground of M31

“…Through the HALO7D 8 observing program (begun in Spring 2014), we will obtain deep (8-24 hr integrations) spectra of hundreds of distant MSTO halo stars with measured HST PMs using Keck II/ DEIMOS. We will target N∼350 stars in the four CANDELS fields (Grogin et al 2011;Koekemoer et al 2011): GOODS-N, GOODS-S, COSMOS, and EGS. All four of these fields are characterized by deep, multi-epoch HST imaging, and cover a total area of approximately 1000 square arcminutes.…”

The Impact of JWST Broadband Filter Choice on Photometric Redshift Estimation

“…In order to obtain multiwavelength photometry for these galaxies, we cross-matched this sample with the public Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS; Grogin et al 2011;Koekemoer et al 2011) catalog for the Great Observatory Origins Deep Survey South field (GOODS-S) obtained by Guo et al (2013). This catalog contains photometry in 17 broadbands, from 0.37 through 8.0 μm, obtained with ground-and space-based telescopes, including HST and Spitzer (Ashby et al 2015).…”

Comparing Dark Energy Survey andHST–CLASH observations of the galaxy cluster RXC J2248.7−4431: implications for stellar mass versus dark matter

“…The CLASH mosaics were produced using the 'MosaicDrizzle' pipeline (see Koekemoer et al 2011). The CLASH catalogue creation pipeline makes use of SEXTRACTOR: the software is run in dual image mode, where a detection image is created from a weighted sum of the ACS/WFC and WFC3/IR images.…”