Abstract
The unidentified very-high-energy (VHE; E>0.1 TeV)γ-ray source, HESS J1826−130, was discovered with the High Energy Stereoscopic System(HESS) in the Galactic plane. The analysis of 215 h of HESS data has revealed a steadyγ-ray flux from HESS J1826−130, which appears extendedwith a half-width of 0.21◦±0.02◦stat±0.05◦sys. The source spectrum is best fit with either a power-law function with a spectral indexΓ =1.78±0.10stat±0.20sysand an exponential cut-offat 15.2+5.5−3.2TeV, or a broken power-law withΓ1=1.96±0.06stat±0.20sys,Γ2=3.59±0.69stat±0.20sysfor energies below and aboveEbr=11.2±2.7 TeV, respectively. The VHE flux from HESS J1826−130 is contaminated by the extended emission ofthe bright, nearby pulsar wind nebula (PWN), HESS J1825−137, particularly at the low end of the energy spectrum. Leptonic scenarios for theorigin of HESS J1826−130 VHE emission related to PSR J1826−1256 are confronted by our spectral and morphological analysis. In a hadronicframework, taking into account the properties of dense gas regions surrounding HESS J1826−130, the source spectrum would imply an astrophysicalobject capable of accelerating the parent particle population up to&200 TeV. Our results are also discussed in a multiwavelength context, accountingfor both the presence of nearby supernova remnants (SNRs), molecular clouds, and counterparts detected in radio, X-rays, and TeV energies
Angüner, EO