Related papers: Gamma-ray heartbeat powered by the microquasar SS …
After initial claims and a long hiatus, it is now established that several binary stars emit high (0.1-100 GeV) and very high energy (>100 GeV) gamma rays. A new class has emerged called 'gamma-ray binaries', since most of their radiated…
Population studies of unidentified EGRET sources suggest that there exist at least three different populations of galactic gamma-ray sources. One of these populations is formed by young objects distributed along the galactic plane with a…
Microquasars are accreting X-ray binary systems with non-thermal radio jets. In some of these systems the jet is expected to be strongly misaligned with the perpendicular to the orbital plane. If the donor star is an early-type star, the…
Microquasars are stellar x-ray binaries that behave as a scaled down version of extragalactic quasars. The star LS 5039 is a new microquasar system with apparent persistent ejection of relativistic plasma at a 3 kiloparsec distance from the…
Microquasars, X-ray binary systems that generate relativistic jets, were discovered in our Galaxy in the last decade of the XXth century. Their name indicates that they are manifestations of the same physics as quasars but on a completely…
We present an analysis of 17 years of Fermi-LAT observations of the microquasar SS~433. We detect four GeV sources in the region: a newly identified source, PS J1910+0550, located outside W50; the previously reported source J1913+0512; and…
The SS433 is a well-known binary system with an internal black hole, which is stripping mass from an orbiting companion of ten solar masses, at a hundred of light-seconds away. The black hole and its accretion disk fuel a thin precessing…
We investigate the production of gamma-rays in the inner regions of SS 433 and in its interaction between its jets and the W50 nebula. We estimate the VHE emission that can be generated within the jets at distances above 1e+13 cm from the…
The extragalactic analogs of the microquasars, the quasars, are strong gamma-ray emitters at GeV energies. It is expected that microquasars are also gamma-ray sources, because of the analogy with quasars and because theoretical models…
Microquasars are radio-emitting X-ray binaries accompanied by relativistic jets. They are established sources of 100~TeV gamma rays and are considered promising candidates for cosmic-ray acceleration. Motivated by recent detections of $\sim…
We discuss the gamma-ray absorption in the inner region of the microquasar SS433. Our investigation includes several contributions to the opacity of this system. They result from the ambient fields generated by the primary star, possibly an…
Black holes (BH), one of the most intriguing objects in the universe, can manifest themselves through electromagnetic radiation initiated by the accretion flow. Some stellar-mass BHs drive relativistic jets when accreting matter from their…
The jets of microquasars with high-mass stellar companions are exposed to the dense matter field of the stellar wind. We present estimates of the gamma-ray emission expected from the jet-wind hadronic interaction and we discuss the…
The discovery of non-thermal X-ray emission from the jets of some X-ray binaries, and especially the discovery of GeV-TeV gamma-rays in some of them, provide a clear evidence of very efficient acceleration of particles to multi-TeV energies…
SS 433 is a binary system containing a supergiant star that is overflowing its Roche lobe with matter accreting onto a compact object (either a black hole or neutron star). Two jets of ionized matter with a bulk velocity of $\sim0.26c$…
SS 433 is a microquasar whose relativistic jets precess every ~162 days, providing a laboratory for jet-interstellar medium interactions. We present a comprehensive analysis of 16 years of Fermi Large Area Telescope data (August…
The launch of the Fermi gamma-ray space telescope and the imaging air Cerenkov telescopes H.E.S.S., MAGIC, and VERITAS have substantially transformed our knowledge of gamma-ray sources in the last decade. The extragalactic gamma-ray sky is…
Microquasars, Galactic binary systems showing extended and variable radio emission, are potential gamma-ray emitters. Indications of gamma-ray transient episodes have been reported in at least two systems, Cyg X-1 and Cyg X-3. The…
Gamma-rays, the most energetic photons, carry information from the far reaches of extragalactic space with minimal interaction or loss of information. They bring messages about particle acceleration in environments so extreme they cannot be…
The SS433, a well-known binary system with an internal black hole, have shown since half a century, an inner (a few year light distances) twin precessing jets spirals. These beams are made by tidal forces while stripping mass from large…