uGMRT observation of the unidentified PeVatron candidate LHAASO J2108+5157

TL;DR

This study uses GMRT radio observations to investigate a PeV-energy particle source detected by LHAASO, revealing an extended radio source with disk-jet morphology that may be responsible for the ultra-high-energy photons.

Contribution

First radio survey of the LHAASO J2108+5157 region identifying a potential counterpart with disk-jet morphology.

Findings

Detected an extended radio source within LHAASO's PSF.

Radio source shows disk-jet morphology suggesting particle acceleration.

Possible association between radio source and PeV photon emission.

Abstract

Recent observations by the Large High Altitude Air Shower Observatory (LHAASO) detected Ultra High Energy (UHE) photons in the range 100 TeV to 1.4 PeV from twelve sources including Crab nebula. The detection of these photons demands the presence of at least PeV energy particle in the source. It is important to understand particle acceleration and radiation emission processes in such source. One of those twelve sources, LHAASO J2108+5157 does not show any association or counterparts at any other wavelength. In search of counterpart, we surveyed the region with Giant Metrewave Radio Telescope (GMRT) at 650 MHz frequency. GMRT observation revel radio emission from an extended source within the PSF of LHAASO which shows disk-jet morphology. Considering the spatial association and extent of the source, it is plausible that particle acceleration to PeV energies originates from this source.