Abstract
We derive photometric redshifts (z phot) for sources in the entire (∼0.4 deg2) Hawaii-Hubble Deep Field-North (H-HDF-N) field with the EAzY code, based on point-spread-function-matched photometry of 15 broad bands from the ultraviolet (U band) to mid-infrared (IRAC 4.5 μm). Our catalog consists of a total of 131,678 sources. We evaluate the z phot quality by comparing z phot with spectroscopic redshifts (z spec) when available, and find a value of normalized median absolute deviation σNMAD = 0.029 and an outlier fraction of 5.5% (outliers are defined as sources having |zphot-zspec |/(1 + zspec) > 0.15) for non-X-ray sources. More specifically, we obtain σNMAD = 0.024 with 2.7% outliers for sources brighter than R = 23 mag, σNMAD = 0.035 with 7.4% outliers for sources fainter than R = 23 mag, σNMAD = 0.026 with 3.9% outliers for sources having z < 1, and σNMAD = 0.034 with 9.0% outliers for sources having z > 1. Our z phot quality shows an overall improvement over an earlier z phot work that focused only on the central H-HDF-N area. We also classify each object as a star or galaxy through template spectral energy distribution fitting and complementary morphological parameterization, resulting in 4959 stars and 126,719 galaxies. Furthermore, we match our catalog with the 2 Ms Chandra Deep Field-North main X-ray catalog. For the 462 matched non-stellar X-ray sources (281 having z spec), we improve their z phot quality by adding three additional active galactic nucleus templates, achieving σNMAD = 0.035 and an outlier fraction of 12.5%. We make our catalog publicly available presenting both photometry and z phot, and provide guidance on how to make use of our catalog.
Original language | English (US) |
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Article number | 27 |
Journal | Astrophysical Journal, Supplement Series |
Volume | 215 |
Issue number | 2 |
DOIs | |
State | Published - Jan 1 2015 |
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science