A Complete X-ray Spectral Survey of ISP BL Lac Objects in the 4LAC-DR3 High-Confidence Catalog: Evidence for a Rare Spectral Hardening Class
Year: 2026
Type: preprint
Abstract: We present the first complete X-ray spectral survey of all 347 ISP BL Lac objects in the 4LAC-DR3 high-confidence catalog using archival Swift-XRT data. Of 347 targets, 242 had sufficient data, yielding 220 Class-S and 14 Class-H objects. Only 1WGA J0506.6-0857 exhibits statistically significant spectral hardening (p=0.037, beta=2.11). Results are interpreted under the delta-P_Ma Hypothesis (Katayama 2026). ORCID: 0009-0006-2290-6593 | TheYKHC Independent Research Institute
Author: Katayama, Yoshimitsu
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7162944558