Related papers: Broad-band electromagnetic radiation from microqua…
Most of the hadronic jet models for quasars (QSOs) and microquasars (MQs) found in literature represent beams of particles (e.g. protons). These particles interact with the matter in the stellar wind of the companion star in the system or…
Microquasars (MQs) are binary systems composed by a star feeding mass to a compact object through an accretion disk. The compact object, usually a black hole, launches oppositely directed jets which are typically observed in our galaxy…
We consider the production of positrons in microquasars, i.e. X-ray binary systems that exhibit jets frequently, but not continuously. We estimate the production rate of positrons in microquasars, both by simple energy considerations and in…
X-ray emission from large scale extragalactic jets is likely to be due to inverse Compton scattering of relativistic particles off seed photons of both the cosmic microwave background field and the blazar nucleus. The first process…
The origin of Galactic cosmic rays remains a matter of debate, but supernova remnants are commonly considered to be the main place where high-energy cosmic rays are accelerated. Nevertheless, current models predict cosmic-ray spectra that…
We present a model to estimate the synchrotron radio emission generated in microquasar (MQ) jets due to secondary pairs created via decay of charged pions produced in proton-proton collisions between stellar wind ions and jet relativistic…
Microquasars (MQs) are Galactic binary systems, consisting of a star and a compact object, a neutron star or a stellar mass black hole, which accretes matter from its companion star and gives rise to relativistic jets. Recent detection of…
High-mass microquasars are binary systems composed by a massive star and a compact object from which relativistic jets are launched. Regarding the companion star, observational evidence supports the idea that winds of hot stars are formed…
X-ray binaries are composed of a normal star in orbit around a neutron star or stellar-mass black hole. Radio and X-ray observations have led to the presumption that some X-ray binaries called microquasars behave as scaled down active…
Relativistic outflows are a common phenomenon in accreting black holes. Despite the enormous differences in scale, accreting stellar-mass black holes (X-ray binaries, collapsars) and super-massive black holes produce jets with analogous…
The interaction of microquasar jets with their environment can produce non-thermal radiation as is the case for extragalactic outflows impacting on their surroundings. We have developed an analytical model based on those successfully…
The possible associations between the microquasars LS 5039 and LS I +61 303 and the EGRET sources 3EG J1824-1514 and 3EG J0241+6103 suggest that microquasars could also be sources of high-energy gamma-rays. In this work, we present a…
The radiation observed by blazars is believed to originate from the transformation of bulk kinetic energy of relativistic jets into random energy. A simple way to achieve this is to have an intermittent central power source, producing…
Current research indicates that the radiation of the first stars alone would not have been suficient to ionize the intergalactic medium on long distances because of the high columnar density of the clouds in which they formed. It becomes…
Recent radio observations support a picture for star formation where there is accretion of matter onto a central protostar with the ejection of molecular outflows that can affect the surrounding medium. The impact of a supersonic outflow on…
Microquasars are binary systems that harbor a normal star and a compact object (black-hole or neutron star), and show relativistic outflows (or jets). The matter that forms these jets is of likely stellar origin, previously expelled from…
The recently detected extended, very-high-energy gamma-ray emission from the microquasar V4641 Sgr reveals a puzzling 200-parsec-long jet-like structure significantly misaligned with its radio jet. We propose that this gamma-ray structure…
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…
There is an increasing number of observational evidence that very high energy gamma-rays in radio-loud active galactic nuclei are produced in the direct vicinity of a supermassive black hole (SMBH), close to the base of a relativistic jet.…
Microquasars are X-ray binaries with relativistic jets. These jets are powerful energy carriers, thought to be fed by accretion, which produce non-thermal emission at different energy bands. To date, several Galactic sources showing…