We report on INTEGRAL observations of AX J1838.0-0655 , one of the unidentified objects listed in the first IBIS/ISGRI survey catalogue and located in the Scutum arm region .
This object , detected in the 20-300 keV band at a confidence level of 15.3 \sigma ( 9 \times 10 ^ { -11 } erg cm ^ { -2 } s ^ { -1 } ) is the likely counterpart of the still unidentified TeV source HESS J1837-069 .
It has been detected in the past by various X-ray telescopes , including ASCA , implying that it is a persistent rather than a transient source ; the ASCA image is compatible with the source not being resolved .
The broad 1-300 keV spectrum is characterized by an absorbed ( N _ { H } =6.7 \pm 1.3 \times 10 ^ { 22 } cm ^ { -2 } ) and hard ( \Gamma =1.5 \pm 0.2 ) power law continuum .
Possible counterparts ( radio and infrared ) present within the X-ray error box are discussed , even if no clear association can be identified .
The broad band spectrum together with the TeV detection suggests that AX J1838.0-0655 maybe a supernova remnant or a pulsar wind nebula , which has so far eluded detection in the radio band .
This is the second unidentified HESS source that shows a substantial soft gamma-ray emission .