2025/02/24 by Dhayaa Anbajagane, Anbajagane, D., A. Alarcon +124 · 1 voice · 5 citations
Physics and Astronomy · #Adaptive optics and wavefront sensing #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena
paper · pdf · doi:10.33232/001c.146159
openalex publication_date 2025/10/22 · openalex created_date 2025/10/24 · openalex updated_date 2026/07/23
We present the photometric redshift characterization and calibration for the Dark Energy Camera All Data Everywhere (DECADE) weak lensing dataset: a catalog of 107 million galaxies observed by the Dark Energy Camera (DECam) in the northern Galactic cap. The redshifts are estimated from a combination of wide-field photometry, deep-field photometry with associated redshift estimates, and a transfer function between the wide field and deep field that is estimated using a source injection catalog. We construct four tomographic bins for the galaxy catalog, and estimate the redshift distribution, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:mi>n</mml:mi> <mml:mrow> <mml:mo stretchy="true" form="prefix">(</mml:mo> <mml:mi>z</mml:mi> <mml:mo stretchy="true" form="postfix">)</mml:mo> </mml:mrow> </mml:mrow> </mml:math> , within each one using the Self-organizing Map Photo-Z (SOMPZ) methodology. Our estimates include the contributions from sample variance, zeropoint calibration uncertainties, and redshift biases, as quantified for the deep-field dataset. The total uncertainties on the mean redshifts are <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:msub> <mml:mi>σ</mml:mi> <mml:mrow> <mml:mo stretchy="false" form="prefix">⟨</mml:mo> <mml:mi>z</mml:mi> <mml:mo stretchy="false" form="postfix">⟩</mml:mo> </mml:mrow> </mml:msub> <mml:mo>≈</mml:mo> <mml:mn>0.01</mml:mn> </mml:mrow> </mml:math> . The SOMPZ estimates are then compared to those from the clustering redshift method, obtained by cross-correlating our source galaxies with galaxies in spectroscopic surveys, and are shown to be consistent with each other.