PEARLS: NuSTAR and XMM-Newton Extragalactic Survey of the JWST North Ecliptic Pole Time-Domain Field III

Abstract The James Webb Space Telescope North Ecliptic Pole (NEP) Time-Domain Field (TDF) has been monitored by Nuclear Spectroscopic Telescope Array (NuSTAR) and XMM-Newton with a regular cadence for 5 yr, starting in 2019. The survey has accumulated 3.5 Ms of NuSTAR exposure and 228 ks quasi-simultaneous XMM-Newton observations covering 0.31 deg 2 . This paper presents the results from the most recent 2 years’ worth of 2 Ms NuSTAR and 166 ks XMM observations in NuSTAR cycles 8 and 9. These observations reached a 20% area flux of 2.20 × 10 −14 erg cm −2 s −1 in the 8–24 keV band. Note that 75 NuSTAR sources and 274 XMM-Newton sources are detected at 99% reliability level. The log N –log S measured in cycles 8+9 are consistent with those measured in the previous cycle 5+6 NuSTAR NEP survey, but in a larger area (0.3 deg 2 compared with 0.19 deg 2 ). The slope of the cycles 8+9 8−24 keV log N –log S curve is flatter than other works ( α 89 = 1.13 ± 0.46), but is consistent with the Euclidean value of α = 1.50. In addition, we found ∼36% of the NuSTAR sources to be heavily obscured ( N H ≥ 10 23 cm −2 ). The Compton-thick ( N H ≥ 10 24 cm −2 ) active galactic nuclei fraction is 9 − 8 + 18 % in the NEP-TDF, which is consistent with the measurements in previous surveys.