Multiwavelength study of the northeastern outskirts of the extended TeV source HESS J1809-193

TL;DR

This study investigates the northeastern outskirts of the extended TeV gamma-ray source HESS J1809-193 using multiwavelength data, concluding it may be a dark accelerator with no clear lower-energy counterparts.

Contribution

The paper provides the first detailed multiwavelength analysis of the HESS J1809-193 outskirts, suggesting it is a potential dark accelerator without identifiable lower-energy sources.

Findings

XTE J1810-189 is a variable X-ray burster unlikely to produce TeV emission.

Other X-ray binaries and SNR G11.4-0.1 are unlikely TeV sources.

The northeastern extension may be a dark accelerator with no lower-energy counterparts.

Abstract

HESS J1809-193 is an extended TeV gamma-ray source in the Galactic Plane. Multiwavelength observations of the HESS J1809-193 field reveal a complex picture. We present results from three CXO and two Suzaku observations of a region in the northeastern outskirts of HESS J1809-193, where enhanced TeV emission has been reported. Our analysis also includes GeV gamma-ray and radio data. One of the X-ray sources in the field is the X-ray binary XTE J1810-189, for which we present the outburst history from multiple observatories and confirm that XTE J1810-189 is a strongly variable type I X-ray burster, which can hardly produce TeV emission. We investigate whether there is any connection between the possible TeV extension of HESS J1809-193 and the sources seen at lower energies. We find that another X-ray binary candidate, Suzaku J1811-1900, and a radio supernova remnant, SNR G11.4-0.1, can hardly be responsible for the putative TeV emission. Our multiwavelength classification of fainter X-ray point sources also does not produce a plausible candidate. We conclude that the northeast extension of HESS J1809-193, if confirmed by deeper observations, can be considered as a dark accelerator - a TeV source without visible counterpart at lower energies.