SRGz: Classification of eROSITA Point X-ray Sources in the 1%DESI Region and Calibration of Photometric Redshiftsстатья
Информация о цитировании статьи получена из
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 10 апреля 2024 г.
Аннотация:We consider the population of point X-ray sources from the two-year SRG/eROSITA survey in the 1 DESI spectroscopic survey region in the eastern Galactic hemisphere (eROSITA-1 DESI-East). The data under consideration combine a large survey area (compared to the medium-format Stripe82X and XMM-XXL X-ray surveys) and a record high completeness of spectroscopy for the optical counterparts of X-ray sources. We compare the results of the photometric (SRGz) and spectroscopic/astrometric (DESI EDR, SDSS, HELP, GAIA) measurements of the classes and redshifts of objects in three X-ray-flux-limited eROSITA-1 DESI-East samples: FX,0.5−2≥slant4×10−14 erg s −1 cm −2 (bright), FX,0.5−2=(1.5−4)×10−14 erg s −1 cm −2 (medium), and FX,0.5−2=(0.6−1.5)×10−14 erg s −1 cm −2 (faint) with a total area of 91.4, 91.4, and 16.62 sq.deg ,respectively. We propose a new method of postprocessing the probabilistic photo−z predictions based on a two−temperature correction of the probability density function PDF(z). This approach allows the calibration of the probabilistic predictions and confidence intervals of the photometric redshifts for eROSITA X-ray sources obtained by SRGz to be improved significantly.