Related papers: Studying the Structure of the Stellar Wind in LS 5…
The persistent soft X-ray emission from the location of the so-far most luminous supernova (SN), ASASSN-15lh (or SN 2015L), with $L \sim 10^{42} \rm erg~ s^{-1}$, is puzzling. We show that it can be explained by radiation from the SN-shock…
Context. Radiation-driven mass loss is key to our understanding of massive-star evolution. However, for low-luminosity O-type stars there are big discrepancies between theoretically predicted and empirically derived mass-loss rates (called…
For the first time, based on long-term spectral monitoring with high spectral resolution, the optical spectrum of the weak central star of the IR source RAFGL 5081 has been studied. The spectral type of this star is close to G5-8 II, and…
PSR J2032+4127 is a young and rapidly rotating pulsar on a highly eccentric orbit around the high-mass Be star MT91 213. X-ray monitoring of the binary system over a $\sim$4000 day period with Swift has revealed an increase of the X-ray…
The relatively nearby (distance=24.1 Mpc) elliptical galaxy NGC821, hosting a central massive black hole but inactive at all wavelengths, was observed with Chandra for a total exposure of 230 ksec, to search for nuclear emission and gas…
The radio supernova remnant W50 hosts at its center the peculiar galactic X-ray binary SS 433. It shows a central spherical structure with two `ears' which are supposed to be formed by the interaction of the precessing jets of SS 433 with…
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…
W50 is a radio nebula around hyper-accreting Galactic microquasar SS~433. Here we focus on one peculiar feature of W50 - a pair of so-called "extended X-ray jets" (EXJs). These "jets" have a size of $\sim20\, {\rm pc}$, a sharp inner…
Gamma-ray binaries present emission that is variable and can reach UHE. The processes behind the acceleration of the particles that produce this very energetic radiation are yet to be understood. We probe the properties of the particle…
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…
The detection of TeV gamma-rays from LS 5039 and the binary pulsar PSR B1259-63 by HESS, and from LS I +61 303 and the stellar-mass black hole Cygnus X-1 by MAGIC, provides a clear evidence of very efficient acceleration of particles to…
LHAASO J2108+5157 is one of the few ultra-high energy gamma-ray sources in the LHAASO catalogue without secure counterpart at longer wavelengths. Several Galactic scenarios have been proposed, including an evolved supernova remnant and a…
We present observations of L1014, a dense core in the Cygnus region previously thought to be starless, but data from the Spitzer Space Telescope shows the presence of an embedded source. We propose a model for this source that includes a…
The origin and radiation mechanisms of high energy emissions from pulsars have remained mysterious since their discovery. Here we report, based on a sample of 68 pulsars, observational connection of non-thermal X-ray emissions from pulsars…
PSR B1259-63 is a 48 ms radio pulsar in a highly eccentric 3.4 year orbit with a Be star SS 2883. Unpulsed gamma-ray, X-ray and radio emission components are observed from the binary system. It is likely that the collision of the pulsar…
The gamma-ray binary LS I +61 303 is one of the brightest Fermi sources, with orbitally modulated emission across the electromagnetic spectrum. Here we present H-alpha spectra of LS I +61 303 that exhibit a dramatic emission burst shortly…
We consider nebulae which are created around binary systems containing rotation powered pulsars and companion stars with strong stellar winds. It is proposed that the stellar and pulsar winds have to mix at some distance from the binary…
TeV gamma-ray emission from two massive binaries of the microquasar type, LS 5039 and LS I +61$^{\rm o}$ 303, show clear variability with their orbital periods. Our purpose is to calculate the GeV and TeV $\gamma$-ray light curves from the…
We examine mechanisms that may explain the luminosities and relatively low temperatures of extended X-ray emission in planetary nebulae. By building a simple flow structure for the wind from the central star during the proto, and early,…
Non-thermal variable emission from radio to very-high energy gamma rays (VHE; >100 GeV) are the prime characteristics of gamma-ray binaries. The underlying physical processes leading to the observed VHE emission are not well understood, as…