Szczegóły seminarium

Data: 18.10.2022

Dominika Król (UJ Krakow)

Gravitational Microlensing Events in the Optical Lightcurve of Active Galaxy S5 0716+714

A well-known blazar S5 0716+714 is characterized by a particularly high variability duty cycle on short-time scales at optical frequencies, therefore it was subjected to numerous monitoring programs, including both ground-based as well as space-borne telescopes. I will discuss the several conspicuous events with `volcano-like' symmetric shapes, lasting all for several hours, which we found in the most recent accumulation of the data provided by the Transiting Exoplanet Survey Satellite. We propose that those peculiar features could be due to the gravitational micro-lensing of the innermost segments of the precessing jet in the system, by a binary lens. We were able to successfully fit all the selected events with a single lens, adjusting slightly only the source trajectory parameters for each lensing event, using first the inverse-ray shooting method and then Python package MuLensModel for quantitive analysis. Based on the fitting results we postulate the presence of a massive binary lens, containing an intermediate-mass black hole, possibly even a super-massive one, and a much less massive companion located within the host galaxy of the blazar, most likely the central kiloparsec region.

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