相关论文: Gamma-ray absorption in the microquasar SS433

Microquasars have been expected to emit high energy gamma-rays due to their general similarities to the gamma-ray emitting blazars (evidences of relativistic jets, non-thermal radio to X-ray emission). In fact, the first source of this…

The evolution of the dark matter distribution at the Galactic center is analyzed, which is caused by the combination of gravitational scattering on Galactic bulge stars and absorption by a supermassive black hole at the center of the bulge.…

X-ray binaries have been an important key in understanding the jet-disc symbiosis in accreting black holes on all mass scales, from stellar-mass to supermassive black holes. SS433 was the first Galactic XRB that has been extensively studied…

Several binary systems consisting of a massive star and a compact object have been detected above 100 GeV in the Galaxy. In most of these sources, gamma-rays show a modulation associated to the orbital motion, which means that the emitter…

SS433 is the prototype microquasar in the Galaxy and may even be analogous to the ULX sources if the jets' kinetic energy is taken into account. However, in spite of 20 years of study, our constraints on the nature of the binary system are…

We suggest that the ultraluminous X-ray sources located in external galaxies (ULXs) are supercritical accretion disks like that in SS433, observed close to the disk axis. We estimate parameters of the SS433 funnel, where the relativistic…

Fermi has discovered two giant gamma-ray-emitting bubbles that extend nearly 10kpc in diameter north and south of the galactic center (GC). The existence of the bubbles was first evidenced in X-rays detected by ROSAT and later WMAP detected…

Recent Chandra and XMM observations of distant quasars have shown strong local (z~0) X-ray absorption lines from highly ionized gas, primarily He-like oxygen. The nature of these X-ray absorbers, i.e., whether they are part of the hot gas…

The measurement of gamma rays at MeV energies from cosmic radioactivities is one of the key tools for nuclear astrophysics, in its study of nuclear reactions and how they shape objects such as massive stars and supernova explosions.…

We present a hadronic model for gamma-ray production in the microquasar LS I $+61 303$. The system is formed by a neutron star that accretes matter from the dense and slow equatorial wind of the Be primary star. We calculate the gamma-ray…

SS 433 is a microquasar, a stellar binary system with collimated relativistic jets. We observed SS 433 in gamma rays using the High Energy Stereoscopic System (H.E.S.S.), finding an energy-dependent shift in the apparent position of the…

The Large High Altitude Air Shower Observatory (LHAASO) has revealed numerous ultrahigh-energy gamma-ray sources of unknown origin. We propose that a fraction of them can be explained by microquasar remnants, i.e., binary systems where mass…

The X-ray, Ultraviolet, Optical emission from radio-quiet AGNs, black hole binaries, and other compact sources, in general, follow a lognormal flux distribution, a linear rms-flux relation, and a (broken) power-law power spectral densities…

The broad-line region (BLR) is an important component of blazars, especially for the flat spectrum radio quasars (FSRQs). The soft photons arising from the BLR will substantially affect the transparency of the gamma-ray photons produced in…

We have discovered an x-ray source, SAX J0635+0533, with a hard spectrum within the error box of the GeV gamma-ray source in Monoceros, 2EG J0635+0521. The unabsorbed x-ray flux is 1.2*10^-11 erg cm^-2 s^-1 in the 2-10 keV band. The x-ray…

Gamma-ray astronomy will play a crucial role in the investigation of nonthermal processes in the large scale structure of the universe. Particularly, galaxy clusters (GC) observations at this photon energy will help us understand the origin…

Major flows of ionized gas are thought to be present in the nuclei of most luminous QSOs, and absorption by these flows often has a significant effect upon the observed X-ray continuum from the black hole region. We briefly discuss X-ray…

Oscillatory structure is found in the atomic background absorption in x-ray-absorption fine structure (XAFS). This atomic-XAFS or AXAFS arises from scattering within an embedded atom, and is analogous to the Ramsauer-Townsend effect.…

A derivation of the \gamma\gamma --> e^+ e^- optical depth for \gamma rays produced in a comoving spherical emitting region is presented. Employing a simplified expression for the \gamma\gamma absorption cross section, analytic expressions…

We calculate the gamma-ray albedo due to cosmic-ray interactions with debris (small rocks, dust, and grains) in the Oort Cloud. We show that under reasonable assumptions a significant proportion of what is called the "extragalactic…