Searching for optical and VHE counterparts of fast radio bursts with MAGIC

TL;DR

This paper reports on MAGIC telescope observations of fast radio bursts, especially the repeating FRB 121102, aiming to detect optical and very high energy counterparts to understand their origins.

Contribution

It presents new observational results and improved strategies for detecting optical and VHE counterparts of FRBs using MAGIC telescopes.

Findings

No optical or VHE counterparts detected during observations.

Enhanced observational strategies and instrument improvements implemented.

Results contribute to constraining models of FRB progenitors.

Abstract

Fast radio bursts (FRBs) are an enigmatic class of extragalactic transients emitting Jy-level radio bursts in the GHz band, lasting for only a few ms. So far, some objects are known to repeat while several others are not, likely indicating multiple origins. There are many theoretical models, some predict prompt VHE or optical emission correlated with FRBs while others imply VHE afterglows hours after the FRB. To test these predictions and unravel the nature of FRB progenitors, the stereoscopic Imaging Atmospheric Cherenkov Telescopes (IACTs) system MAGIC has been participating in FRB observation campaigns since 2016. As IACTs are sensitive to Cherenkov photons in the UV/blue region of the electromagnetic spectrum and use photo-detectors with time response faster than a ms, MAGIC is also able to perform simultaneous optical observations through a dedicated system installed in the central PMT of its camera. The main challenge faced by MAGIC in searching for optical counterpart of FRBs is the presence of irreducible background optical events due to terrestrial sources. We present new results from MAGIC observations of the first repeating FRB 121102 during several MWL observation campaigns. The recently improved instrument and refined strategy to search for counterparts of FRBs in the VHE and optical bands will also be presented.