Study of the Very High Energy emission of M87 through its broadband spectral energy distribution

TL;DR

This paper constructs a broadband spectral energy distribution of M87 during its non-flaring state and uses a lepto-hadronic model to explain its very high energy emission, including an orphan flare.

Contribution

It presents the first comprehensive broadband SED of M87 during non-flaring activity and applies a lepto-hadronic model to explain its VHE emission.

Findings

Lepto-hadronic model successfully fits the non-flaring VHE emission.

Model explains the 2005 orphan flare.

Spectral energy distribution covers radio to gamma rays.

Abstract

The radio galaxy M87 is the central dominant galaxy of the Virgo Cluster. Very High Energy (VHE,$\gtrsim 0.1$ TeV) emission, from M87 has been detected by Imaging Air Cherenkov Telescopes (IACTs ). Recently, marginal evidence for VHE long-term emission has also been observed by the High Altitude Water Cherenkov (HAWC) Observatory, a gamma ray and cosmic-ray detector array located in Puebla, Mexico. The mechanism that produces VHE emission in M87 remains unclear. This emission is originated in its prominent jet, which has been spatially resolved from radio to X-rays. In this paper, we constructed a spectral energy distribution from radio to gamma rays that is representative of the non-flaring activity of the source, and in order to explain the observed emission, we fit it with a lepto-hadronic emission model. We found that this model is able to explain non-flaring VHE emission of M87 as well as an orphan flare reported in 2005.