Aims. LS 5039 is an enigmatic high-mass gamma-ray binary which hosts a powerful O6.5V companion, but the nature of compact object still to be established using multi-wavelength observations.

ABSTRACT HESS J1825-137 is one of the most powerful and luminous TeV gamma-ray pulsar wind nebulae (PWN). To south J1825-137, Fermi-LAT observation revealed a new region GeV emission with three apparent peaks (termed here, GeV-ABC). This study presents interstellar medium (ISM) data spectral energy distribution (SED) modelling towards to understand underlying particle acceleration. We considere...

Several γ-ray binaries have been recently detected by the High-Energy Stereoscopy Array (H.E.S.S.) and the Major Atmospheric Imaging Cerenkov (MAGIC) telescope. In at least two cases, their nature is unknown. In this paper we aim to provide the details of a theoretical model of close γ-ray binaries containing a young energetic pulsar as compact object, earlier presented in recent Letters. This ...

Spam, defined as the transmission of bulk unsolicited messages, has plagued Internet email. Unfortunately, spam is not limited to email. It can affect any system that enables user-to-user communications. The Session Initiation Protocol (SIP) defines a system for user-touser multimedia communications. Therefore, it is susceptible to spam, just as email is. In this document, we analyze the proble...

LS 5039, a possible black hole x-ray binary, was recently observed with Giant Meterwave Radio Telescope. The observed spectrum presented here shows that the spectrum is inverted at the low frequency. When combined with the archival data with orbital phase similar to the present observations, it shows a clear indication of a spectral turnover. The combined data are fitted with a broken power-law...

LS 5039 is an X-ray binary detected at very high energies. Along the orbit, there is a significant detection even during the superior conjunction of the compact object, when very large gamma-ray opacities are expected. Electromagnetic cascades, which may make the system more transparent to gamma-rays, are hardly efficient for reasonable magnetic fields in the massive star surroundings. A jet-li...

Recent High Energy Stereoscopic System (HESS) observations show that microquasars in high-mass systems are sources of very high energy γ-rays. A leptonic jet model for microquasar γ-ray emission is developed. Using the head-on approximation for the Compton cross section and taking into account angular effects from the star’s orbital motion, we derive expressions to calculate the spectrum of γ r...

Gamma-ray emission in the TeV (1012 eV) range has been detected by HESS from two X-ray binaries: PSR B125963 and LS 5039. In both, the early-type star provides large numbers of target photons for pair-production with TeV γ-rays. This results in a modulation of the γ-ray flux as the relative positions of the γ-ray source and companion star change with orbital phase for the observer. The extent t...