PEARLS: NuSTAR and XMM-Newton Extragalactic Survey of the JWST North Ecliptic Pole Time-Domain Field IV: X-Ray Variability Analysis

@misc{silver2026pearls,
  title = {{PEARLS: NuSTAR and XMM-Newton Extragalactic Survey of the JWST North Ecliptic Pole Time-Domain Field IV: X-Ray Variability Analysis}},
  author = {Ross Silver and Francesca Civano and Xiurui Zhao and Samantha Creech and S. P. Willner and Christopher N. A. Willmer and Rogier A. Windhorst and Haojing Yan and Anton M. Koekemoer and Rosalia O'Brien and Rafael Ortiz III and Rolf A. Jansen and Gibson B. Bowling and Payaswini Saikia and W. Peter Maksym and Nico Cappelluti and Francesca Fornasini and Massimo Ricotti and Timothy Carleton and Seth H. Cohen and Rachel Honor and Jake Summers and Jordan C. J. D'Silva and Sibasish Laha and Dan Coe and Christopher J. Conselice and Jose M. Diego and Simon P. Driver and Brenda Frye and Norman A. Grogin and Madeline A. Marshall and Nor Pirzkal and Aaron Robotham and Russell E. Ryan Jr},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.24963},
  eprint = {2609.24963},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.24963},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - PEARLS: NuSTAR and XMM-Newton Extragalactic Survey of the JWST North Ecliptic Pole Time-Domain Field IV: X-Ray Variability Analysis
AU  - Ross Silver
AU  - Francesca Civano
AU  - Xiurui Zhao
AU  - Samantha Creech
AU  - S. P. Willner
AU  - Christopher N. A. Willmer
AU  - Rogier A. Windhorst
AU  - Haojing Yan
AU  - Anton M. Koekemoer
AU  - Rosalia O'Brien
AU  - Rafael Ortiz III
AU  - Rolf A. Jansen
AU  - Gibson B. Bowling
AU  - Payaswini Saikia
AU  - W. Peter Maksym
AU  - Nico Cappelluti
AU  - Francesca Fornasini
AU  - Massimo Ricotti
AU  - Timothy Carleton
AU  - Seth H. Cohen
AU  - Rachel Honor
AU  - Jake Summers
AU  - Jordan C. J. D'Silva
AU  - Sibasish Laha
AU  - Dan Coe
AU  - Christopher J. Conselice
AU  - Jose M. Diego
AU  - Simon P. Driver
AU  - Brenda Frye
AU  - Norman A. Grogin
AU  - Madeline A. Marshall
AU  - Nor Pirzkal
AU  - Aaron Robotham
AU  - Russell E. Ryan Jr
PY  - 2026
DA  - 2026/09/21
PB  - arXiv
DO  - 10.48550/arxiv.2609.24963
UR  - https://arxiv.org/abs/2609.24963
AB  - NuSTAR and XMM-Newton have observed the James Webb Space Telescope (JWST) North Ecliptic Pole (NEP) Time-Domain Field (TDF) for almost five contiguous years starting in 2019. In that time, the NEP X-ray survey has accumulated 3.5 Ms and 228 ks of quasi-simultaneous NuSTAR and XMM-Newton observations, respectively. This paper presents variability results for the 112 NuSTAR and 453 XMM-Newton sources detected in this field, based solely on the X-ray photometric data. Four NuSTAR sources and 11 XMM-Newton sources varied in at least one band at >=99% confidence. The sources with redshift measurements show a relationship between luminosity and variability with 74% of variable sources brighter than 5x the sensitivity limit of the survey. This is supported by about 1/3 of sources with more than 400 counts detected being variable and only 4 sources with fewer counts showing variability. Variability timescales are not well determined, but variability amplitude tends to be larger on longer timescales.
ER  -