[en] A few years ago, the era of very high energy γ-ray astronomy started, when the latest generation of Imaging Atmospheric Cherenkov Telescopes (IACT) like H.E.S.S. began to operate and to resolve the sources of TeV emission. Identifications via multi-wavelength studies reveal that the detected sources are supernova remnants and active galactic nuclei, but also pulsar wind nebulae and a few binaries. One widely discussed open question is, how these sources are able to accelerate particles to such high energies. The understanding of the underlying particle distribution, the acceleration processes taking place, and the knowledge of the radiation processes which produce the observed emission, is, therefore, of crucial interest. Observations in the hard X-ray domain can be a key to get information on these particle distributions and processes. Important for this thesis are the TeV and the hard X-ray range. The two instruments, H.E.S.S. and INTEGRAL, whose data were used, are, therefore, described in detail. The main part of this thesis is focused on the X-ray binary system LS 5039/RX J1826.2-1450. It was observed in several energy ranges. The nature of the compact object is still not known, and it was proposed either to be a microquasar system or a non-accreting pulsar system. The observed TeV emission is modulated with the orbital cycle. Several explanations for this variability have been discussed in recent years. The observations with INTEGRAL presented in this thesis have provided new information to solve this question. Therefore, a search for a detection in the hard X-ray range and for its orbital dependence was worthwhile. Since LS 5039 is a faint source and the sky region where it is located is crowded, a very careful, non-standard handling of the INTEGRAL data was necessary, and a cross-checking with other analysis methods was essential to provide reliable results. We found that LS 5039 is emitting in the hard X-ray energy range. A flux rate and an upper flux limit, dependent on orbital phase, were determined for the energy range 25-200 keV. For the inferior conjunction phase, also a spectrum was obtained and found to be well described by a power law with a photon index of Γ = 2.0 ± 0.2. Our main result is that the hard X-ray emission is modulated with the orbit and this modulation is comparatively in phase with the TeV emission. Although the results of the INTEGRAL analysis are not able to distinguish between the microquasar and the pulsar scenario, they rule out a simple explanation of the TeV variability as a consequence of pure photon-photon absorption. In our work we, therefore, discuss possible alternatives like adiabatic cooling of the electrons as a reason for the correlated modulation. In this case the variability is simply a result of the orbital motion and the larger factor of modulation in the TeV range is caused by additional processes like γ-γ absorption and anisotropic inverse Compton scattering. In the second part of this thesis, the keV - TeV connection of three rotationpowered pulsar wind nebulae (RPWN) is studied. The analysis is focussed on RPWN which have been detected as TeV plerions and two mosaics are created which include PSR J0835-4510 (Vela), PSR J1513-5908 (MSH 15-52) and PSR J1420-6048 (Kookaburra). Only a few per cent of the RPWN observed by INTEGRAL have been identified with young or middle-aged pulsars. The analysis of archival INTEGRAL data, in addition to the already known INTEGRAL sources, reveals an evidence of hard X-ray emission at the position of PSR J1420-6048 from the ''Kookaburra'' TeV plerion G313.3+0.6. The pulsar PSR J1420-6048 belongs to the class of middle-aged pulsars where the RPWN interacts with the reverse shock of the supernova remnant. Altogether, this analysis indicates a deeper link between these TeV plerions and INTEGRAL detected pulsar wind nebulae. The last part of the thesis is devoted to a systematic analysis of the mosaic obtained for the region around LS 5039. In the first place only seen as a byproduct, the 3 x 10⁶ s deep INTEGRAL observation is worthwhile to be studied on its own. All public H.E.S.S. sources and all INTEGRAL sources located in the field of view are listed. One source in particular attracted our attention. This is the accreting pulsating neutron star system AXJ1820.5-1434. The luminosity of this source seems to vary in phase with LS 5039. By analysing the RXTE / ASM data, this is found to be a result of a coincidence between high flux states of AX J1820.5-1434 and the inferior conjunction phase interval chosen for LS 5039. (orig.)