Multi-wavelength Behaviour and Lepto-hadronic Modeling of PKS 0215+015 Around the Epoch of IceCube-220225A

Abstract

The detection of high-energy astrophysical neutrinos has opened a new avenue for identifying cosmic particle accelerators. Blazars, active galactic nuclei (AGN) with relativistic jets oriented close to the observer's line of sight, are promising sites of hadronic interactions capable of producing PeV-scale neutrinos. We investigate the flat-spectrum radio quasar (FSRQ) PKS~0215+015 ($z \simeq 1.715$), positionally consistent with the \textit{IceCube-220225A} neutrino event of estimated energy $\sim$154~TeV. We combine \textit{Fermi}-LAT $γ$-ray data with Swift-XRT and Swift-UVOT observations to characterise the source around the neutrino epoch. PKS~0215+015 exhibited pronounced $γ$-ray, X-ray and optical activity in early 2022, consistent with a disturbance propagating along the jet. We construct broadband spectral energy distributions (SEDs) for the flaring interval and model them using leptonic and lepto-hadronic frameworks. The SED is well reproduced by a leptonic model comprising synchrotron, synchrotron self-Compton and external Compton emission, indicating that electron processes dominate. A co-accelerated proton population remains radiatively subdominant but requires a proton kinetic luminosity roughly two orders of magnitude above equipartition with the magnetic field. The predicted neutrino flux is well below that implied by a single \textit{IceCube-220225A}-like detection. Independent analysis of short-term $γ$-ray variability yields an emission-region size consistent with the SED fit, supporting the model's physical self-consistency. We discuss the temporal and energetic plausibility of the association between PKS~0215+015 and \textit{IceCube-220225A} and implications for future multimessenger studies of high-redshift FSRQs.