X-Ray Intraday Variability of the Blazar OJ 287 Observed with XMM-Newton

Abstract We present X-ray intraday variability, cross-correlated variability, and power spectrum density analysis of the binary black hole blazar candidate OJ 287. The X-ray pointed observations of the source were carried out on eight occasions by the EPIC-pn camera on board the XMM-Newton satellite from 2005 November to 2022 November. The good time intervals range between 3.6 and 24.1 hr. Three energy bands—0.2–2 keV (soft), 2–10 keV (hard), and 0.2–10 keV (total)—have been used to estimate variability. Low amplitude variations are observed in four, five, and six light curves in soft, hard, and total energy bands, respectively. Only two observation IDs have shown variation in the all energy bands. The discrete correlation function of the light curves in soft and hard energy bands peaks at zero lag, suggesting that the emission in both bands was cospatial and came from the same population of leptons. Red noise dominates the power spectral densities of variable light curves. According to our flux and spectrum investigations, both particle acceleration and synchrotron cooling mechanisms contribute significantly to the emission from this blazar.