2008/05/27 by Eilat Glikman, A. Eigenbrod, Alexander Eigenbrod +8
Physics and Astronomy · #Astronomy #Astrophysics #Computer science #Exploratory search #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gamma-ray bursts and supernovae #Information retrieval #Infrared #Limiting #Optical spectra #Physics #Quasar #Redshift #Sky #Spectral line #Stars #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1088/0004-6256/136/3/954
Accepted for pubication in the Astronomical Journal
arxiv created 2008/05/27 · openalex publication_date 2008/07/31 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We conducted an exploratory search for quasars at z ∼ 6–8, using the Early Data Release (EDR) from the United Kingdom Infrared Deep Sky Survey (UKIDSS) cross-matched to panoramic optical imagery. High-redshift quasar candidates are chosen using multi-color selection in i , z , Y , J , H , and K bands. After removal of apparent instrumental artifacts, our candidate list consisted of 34 objects. We further refined this list with deeper imaging in the optical for ten of our candidates. Twenty-five candidates were followed up spectroscopically in the near-infrared and in the optical. We confirmed 25 of our spectra as very low-mass main-sequence stars or brown dwarfs, which were indeed expected as the main contaminants of this exploratory search. The lack of quasar detection is not surprising: the estimated probability of finding a single z > 6 quasar down to the limit of UKIDSS in 27.3 deg 2 of the EDR is <5%. We find that the most important limiting factor in this work is the depth of the available optical data. Experience gained in this pilot project can help refine high-redshift quasar selection criteria for subsequent UKIDSS data releases.