Related papers: The X-Ray Binary Population with Fermi-LAT
A few Galactic objects are known to be variable sources of photons with energies above 100 GeV. These systems are mostly binaries, where variability can often be connected to the orbital period. Particle acceleration and gamma-ray…
The formation and evolution of binary stars is a critical component of several fields in astronomy. The most numerous sources for gravitational wave observatories are inspiraling and/or merging compact binaries, while binary stars are…
The Fermi-LAT Galactic Center excess and the 511 keV positron-annihilation signal from the inner Galaxy bare a striking morphological similarity. We propose that both can be explained through a scenario in which millisecond pulsars produce…
X-ray imaging and spectroscopy can be used to probe the binary content of globular clusters. Binaries are thought to play a key role in the dynamical evolution of the clusters by serving as an internal source of energy which counters the…
Binary stars are as common as single stars. Binary stars are of immense importance to astrophysicists because that they allow us to determine the masses of the stars independent of their distances. They are the cornerstone of the…
Binary systems have long been recognized as the source of powerful astrophysical diagnostics. Among the many applications of binary stars, they have been used as probes of stellar structure and evolution (both of single and binary stars) in…
In the last decade Cherenkov telescopes on the ground and space-based \gamma-ray instruments have identified a new class of high mass X-ray binaries (HMXB), whose emission is dominated by \gamma rays. To date only five of these systems are…
The high mass X-ray binaries (HMXBs) provide an exciting framework to investigate the evolution of massive stars and the processes behind binary evolution. HMXBs have shown to be good tracers of recent star formation in galaxies and might…
We report optical photometric and SOAR spectroscopic observations of an X-ray source found within the localization error of the Fermi-LAT unidentified gamma-ray source J0523.5-2529. The optical data show periodic flux modulation and radial…
We perform binary population synthesis calculations to investigate the incidence of low-mass X-ray binaries and their birth rate in the Galaxy. We use a binary evolution algorithm that models all the relevant processes including tidal…
Gamma-ray binaries are X-ray binaries with gamma-ray emissions. Their multi-wavelength emissions range from radio, optical, X-ray and to very high energy (TeV). X-ray emissions are crucial to understand the nature of gamma-ray binaries.…
We report the results of a deep Chandra survey of the Sculptor dwarf spheroidal galaxy. We find five X-ray sources with $L_X$ of at least $6\times10^{33}$ ergs/sec with optical counterparts establishing them as members of Sculptor. These…
Recently, a spatially extended excess of gamma rays collected by the Fermi-LAT from the inner region of the Milky Way has been detected by different groups and with increasingly sophisticated techniques. Yet, any final conclusion about the…
I show that the spectrum and morphology of a recent Fermi-LAT observation of the Galaxy center are consistent with a millisecond pulsar population in the nuclear Central stellar cluster of the Milky Way. The Galaxy Center gamma-ray spectrum…
Low-mass X-ray binaries (LMXBs) have been studied in the Galaxy since the beginning of X-ray astronomy. A lot has been learned about these bright X-ray sources, but significant questions are still open. These questions are related to the…
Recent studies have found a positive correlation between the star-formation rate of galaxies and their gamma-ray luminosity. Galaxies with a high star-formation rate are expected to produce a large amount of high-energy cosmic rays, which…
The Large Area Telescope (LAT) on Fermi has detected ~150 gamma-ray pulsars, about a third of which were discovered in blind searches of the $\gamma$-ray data. Because the angular resolution of the LAT is relatively poor and blind searches…
A neutron star low-mass X-ray binary is a binary stellar system with a neutron star and a low-mass companion star rotating around each other. In this system the neutron star accretes mass from the companion, and as this matter falls into…
The Fermi Gamma-ray Space Telescope, a key mission in multiwavelength and multimessenger studies, has been surveying the gamma-ray sky from its low-Earth orbit since 2008. Its two scientific instruments, the Gamma-ray Burst Monitor (GBM)…
Close to 100 per cent of massive stars are thought to be in binary systems. The multiplicity of massive stars seems to be intrinsically linked to their formation and evolution, and Massive Young Stellar Objects are key in observing this…