相关论文: Comments on the superluminal motion in Cygnus X-3
We present UKIRT infrared images of the X-ray binary Cygnus X-3. We address the possibility of extended infrared emission and show that it could be either warm circumstellar material or a star near the binary's line of sight.
Cygnus X-3 is a unique microquasar which shows X-ray state changes, strong radio emission, and relativistic jets. It is also an unusual X-ray binary with the mass-donating companion being a high mass star Wolf-Rayet but the orbital…
Cyg X-3 is an unusual X-ray binary which shows remarkable correlative behavior between the hard X-ray, soft X-ray, and the radio. We present an analysis of these long term light curves in the context of spectral changes of the system. This…
We have recently argued that the high-mass X-ray binary Cygnus~X-3 can accelerate cosmic rays (CR) beyond PeV energies. Meanwhile, the LHAASO collaboration published the measurement of an orbitally modulated photon flux from Cygnus~X-3…
Intense flares at cm-wavelengths reaching levels of tens of Jy have been observed from Cygnus X-3 for many years. This active high mass X-ray binary also has periods of quenching before major outbursts, and has minor flares at levels of a…
The microquasar Cygnus X-3 was detected at high energies by the gamma-ray space telescopes AGILE and Fermi. The gamma-ray emission is transient, modulated with the orbital period and seems related to major radio flares, i.e. to the…
Recurrent flaring events at X- and soft gamma-ray energies have been recently reported for the galactic black hole candidate Cygnus X-1. The observed fluxes during these transient outbursts are far higher than what is observed in ``normal''…
Cygnus X-3, among the Galactic X-ray binaries, is one of the brightest radio sources. Radio image as well as spectral analysis shows the presence of outflow in the form of jets. The SED in the X-ray band shows a complicated structure and…
In this article (after some brief theoretical considerations) a bird-eye view is presented -with the help of nine figures- of the various experimental sectors of physics in which Superluminal motions seem to appear. In particular, a…
Cygnus X-3 is a unique microquasar. Its X-ray emission shows a very strong 4.8-hour orbital modulation. But its mass-donating companion is a Wolf-Rayet star. Also unlike most other X-ray binaries Cygnus X-3 is relatively bright in the radio…
The accretion of matter by compact objects can be inhibited by radiation pressure if the luminosity exceeds the critical value, known as the Eddington limit. Discovery of ultraluminous X-ray sources has shown that accretion can proceed even…
We present multiwavelength observations of Cygnus X-3 during an extended outburst in 1994 February - March. Intensive radio monitoring at 13.3, 3.6 & 2.0 cm is complemented by observations at (sub)millimetre and infrared wavelengths, which…
Astrophysical models developed to explain superluminal motion in beaming phenomena are shown to be incomplete and the correct kinematical expression in any case to predict projected velocities slower than the speed of light. The observed…
Cygnus X-3, among the X-ray binaries, is one of the brightest in the radio band, repeatedly exhibiting huge radio flares. The X-ray spectra shows two definite states, low (correspondingly hard) and high (correspondingly soft). During the…
We have discovered extended X-ray emission from the microquasar Cyg X-3 in archival Chandra X-ray Observatory observations. A 5" wide structure lies approximately 16" to the NE from the core point source and may be extended in that…
Cygnus X-3 is a high-mass X-ray binary with a compact object accreting matter from a Wolf-Rayet donor star. Recently, it has been revealed by the Imaging X-ray Polarimetry Explorer (IXPE) as a hidden Galactic ultra-luminous X-ray (ULX)…
High energy gamma-rays have been detected from Cygnus X-3, a system composed of a Wolf-Rayet star and a black hole or neutron star. The gamma-ray emission is linked to the radio emission from the jet launched in the system. The flux is…
The superluminal propagation of neutrinos observed by the OPERA collaboration can be explained by an energy dependent potential for the neutrino beam in passage through the Earth.
In this paper we present a theoretical analysis of an experiment by Mugnai and collaborators where superluminal behavior was observed in the propagation of microwaves. We suggest that what was observed can be well approximated by the motion…
A nonlinear nature of the binary ephemeris of Cygnus X-3 indicates either a change in the orbital period or an apsidal motion of the orbit. We have made extended observations of Cygnus X-3 with the Pointed Proportional Counters (PPCs) of…