Year: 2025
Type: conference-paper
Abstract: Ultra-fast outflows (UFOs) – midly relativistic wide-opening angle winds from active galactic nuclei–haverecentlybeenidentifiedthroughX-rayspectroscopyandmaycontributetotheorigin ofhigh-energycosmicrays. Throughdiffusiveshockacceleration(DSA)atstrongsub-relativistic shocks,UFOscanaccelerateparticlesuptoveryhighenergies(VHE)andevenultra-highenergies (UHE).Interactionsoftheseparticleswiththesurroundingdensemediumareexpectedtoproduce gamma rays andneutrinos. WemodelparticleaccelerationinUFO-drivenshocksusingDSAandestimatetheresultinghigh- energy gamma-ray and neutrino fluxes. We develop a semi-analytical model to predict these emissions andassesstheir detectabilitywith current andfuture observatories. Our preliminary results suggest that some UFOs – particularly nearby ones with high wind velocities (up to 0.4 c) – could be detectable at very high energies. In particular, if the spectrum of accelerated particles is sufficiently hard and the acceleration efficiency is high, some UFOs couldproduceadetectableVHEgamma-rayfluxwhileremainingundetectedintheGeVbandby Fermi-LAT. As a next step, we aim to identify the most promising UFO candidates for detection in the TeV range, with a focus on the CTAO and LHAASO for gamma rays, and IceCube for neutrinos. We also investigate therelativecontributions ofhadronic andleptonic emission scenarios.
DOI: 10.22323/1.501.0722
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W4414509882
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