We introduce a probabilistic approach to select 6<z<8 quasar candidates for spectroscopic follow-up, which is based on density estimation in the high-dimensional space inhabited by the optical and near-infrared photometry. Density distributions are modeled as Gaussian mixtures with principled accounting of errors using the extreme deconvolution (XD) technique, generalizing an approach successfully used to select lower redshift (z<3) quasars. We train the probability density of contaminants on 733,694 7-d flux measurements from the 1076 square degrees overlapping area from the DECaLS (z), VIKING (YJHK), and unWISE (W1W2) imaging surveys, after requiring they dropout of DECaLS g and r, whereas the distribution of high-z quasars are trained on synthetic model photometry. Extensive simulations based on these density distributions and current estimates of the quasar luminosity function indicate that this method achieves a completeness of >75% and an efficiency of >15% for selecting quasars at 6<z<8 with J<21.5. Among the classified sources are 8 known 6<z<7 quasars, of which 2/8 are selected suggesting a completeness ~25%, whereas classifying the 6 known (J<21.5) quasars at z>7 from the entire sky, we select 5/6 or a completeness of ~80%.The failure to select the majority of 6<z<7 quasars arises because our model of quasar SEDs underestimates the scatter in the distribution of fluxes. This new optimal approach to quasar selection paves the way for efficient spectroscopic follow-up of Euclid quasar candidates with ground based telescopes and JWST.
Estimating Photometric Distances to Ultracool Dwarfs in Next Generation Space-based Infrared Surveys: Synthetic Photometry and New Absolute Magnitude Versus Spectral Type Relations for JWST, Euclid, and Roman Filters
Bubble mapping with the Square Kilometer Array -- I. Detecting galaxies with Euclid, JWST, WFIRST and ELT within ionized bubbles in the intergalactic medium at z>6
The red giant branch tip in the SDSS, PS1, JWST, NGRST and Euclid photometric systems. Calibration in optical passbands using Gaia DR3 synthetic photometry
Surveying the Universe in 4D: Beating Cosmic Variance with Wide-Field Slitless Spectroscopy from HST, JWST, Euclid, Roman, and Beyond
Space Telescope Science Institute（太空望远镜科学研究所）；School of Earth and Space Exploration, Arizona State University（亚利桑那州立大学地球与空间探索学院）；Beus Center for Cosmic Foundations, Arizona State University（亚利桑那州立大学宇宙基础布斯中心）；NASA/GSFC（美国国家航空航天局戈达德太空飞行中心）；Massachusetts Institute of Technology（麻省理工学院）
ALMA observations of pre-JWST z ~ 10 galaxy candidates: A CO(J = 9-8) line from a ULIRG at z = 2.54 and revisit of the photometric redshifts with JWST photometry
Waseda University（早稻田大学）；University of Tsukuba（筑波大学）
Euclid: Scaled-up little red dots and other sources with v-shaped spectral energy distributions at z>4
Kapteyn Astronomical Institute, University of Groningen（格罗宁根大学卡普坦天文研究所）；Cosmic Dawn Center (DAWN)（宇宙黎明中心）；Space Telescope Science Institute（太空望远镜科学研究所）；INAF-Osservatorio Astronomico di Padova（帕多瓦国家天体物理研究所天文台）；Dipartimento di Fisica e Astronomia "G. Galilei", Università di Padova（帕多瓦大学伽利略物理与天文学系）；Institute of Science and Technology Austria (ISTA)（奥地利科学技术研究所）；Leiden Observatory, Leiden University（莱顿大学莱顿天文台）
Reconstruction of Cosmic Black Hole Growth and Mass Distribution from Quasar Luminosity Functions at $z>4$: Implications for Faint and Low-mass Populations in JWST
DeepDISC-Euclid: Source Classification and Photometric Redshifts in Euclid Deep Field North With a Pixel-Level Deep Learning Approach
University of Illinois at Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校）；National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign（美国国家超级计算应用中心，伊利诺伊大学厄巴纳-香槟分校）；Center for Artificial Intelligence Innovation, University of Illinois at Urbana-Champaign（人工智能创新中心，伊利诺伊大学厄巴纳-香槟分校）；Max-Planck-Institut für extraterrestrische Physik（马克斯·普朗克地外物理学研究所）；Instituto de Astrofísica de Canarias (IAC)（加那利天体物理研究所；拉帕尔马大学天体物理学系）；Departamento de Astrofísica, Universidad de La Laguna (ULL)（布里斯托大学物理学院）；School of Physics, HH Wills Physics Laboratory, University of Bristol
Bridging the UV Gap: The HST Ultraviolet Foundation for Star Formation Science in the Era of Roman, Euclid, and HWO
INAF-OACN（意大利国家天体物理研究所奥恰诺天文台）；ESO-Garching（欧洲南方天文台加兴）；INAF-Osservatorio Astronomico di Roma（意大利国家天体物理研究所罗马天文台）；University of Colorado Boulder（科罗拉多大学博尔德分校）；UH IfA（夏威夷大学天体物理研究所）；INAF-OAPA（意大利国家天体物理研究所帕尔马天文台）
JWST lensed quasar dark matter survey IV: Stringent warm dark matter constraints from the joint reconstruction of extended lensed arcs and quasar flux ratios
University of Chicago（芝加哥大学）；University of California, Merced（加州大学默塞德分校）；University of California, Los Angeles（加州大学洛杉矶分校）；Stony Brook University（石溪大学）；Carnegie Institution for Science（卡内基科学机构）；University of California, Davis（加州大学戴维斯分校）；The University of Tokyo（东京大学）
A tidal disruption event in a quasar at redshift 7.19
University of Toronto（多伦多大学）；Dunlap Institute for Astronomy and Astrophysics, University of Toronto（多伦多大学邓普天文学与天体物理研究所）；Cosmic Dawn Center (DAWN)（宇宙黎明中心）；Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯·玻尔研究所）；Kavli Institute for Astronomy and Astrophysics, Peking University（北京大学科维理天文与天体物理研究所）；Department of Astronomy, School of Physics, Peking University（北京大学物理学院天文学系）；The University of Texas at Austin（德克萨斯大学奥斯汀分校）；Max-Planck-Institut für extraterrestrische Physik（马克斯·普朗克地外物理学研究所）
