Multiwavelength Investigation of $\gamma$-ray Source MGRO J1908+06 Emission Using Fermi-LAT, VERITAS, and HAWC

TL;DR

This study combines data from Fermi-LAT, VERITAS, HAWC, and LHAASO to analyze the spectral and morphological features of MGRO J1908+06, supporting the hypothesis that an evolved pulsar wind nebula powers its gamma-ray emission.

Contribution

It provides a comprehensive multiwavelength analysis and modeling that identifies the pulsar wind nebula as the source of gamma-ray emission, constraining key physical parameters.

Findings

Gamma-ray emission likely from an evolved pulsar wind nebula

Best-fit pulsar age of approximately 22 kyr

Magnetic field strength around 5.4 microGauss

Abstract

This paper investigates the origin of the $\gamma$-ray emission from MGRO J1908+06 in the GeV-TeV energy band. By analyzing the data collected by {\it Fermi}-LAT, VERITAS, and HAWC, with the addition of spectral data previously reported by LHAASO, a multiwavelength (MW) study of the morphological and spectral features of MGRO J1908+06 provides insight into the origin of the $\gamma$-ray emission. The mechanism behind the bright TeV emission is studied by constraining the magnetic field strength, the source age and the distance through detailed broadband modeling. Both spectral shape and energy-dependent morphology support the scenario that inverse-Compton (IC) emission of an evolved pulsar wind nebula (PWN) associated with PSR J1907+0602 is responsible for the MGRO J1908+06 $\gamma$-ray emission with a best-fit true age of $T=22\pm 9$ kyr and a magnetic field of $B=5.4 \pm 0.8\ \mu\mathrm{G}$, assuming the distance to the pulsar $d_{\mathrm{PSR}}=3.2$ kpc.