1,187 research outputs found
The X-ray Fundamental Plane and Relation of Clusters of Galaxies
We analyze the relations among central gas density, core radius, and
temperature of X-ray clusters by plotting the observational data in the
three-dimensional (, , and ) space and find that
the data lie on a 'fundamental plane'. Its existence implies that the clusters
form a two-parameter family. The data on the plane still has a correlation and
form a band on the plane. The observed relation turns
out to be the cross section of the band perpendicular to the major axis, while
the major axis is found to describe the virial density. We discuss implications
of this two-parameter family nature of X-ray clusters.Comment: 7 pages, 2 figures. To be published in ApJ Letter
Modulation Mechanism of TeV, GeV, and X-ray Emission in LS5039
The emission mechanism of the gamma-ray binary LS5039 in energy bands of TeV,
GeV, and X-ray is investigated. Observed light curves in LS5039 show that TeV
and GeV fluxes anticorrelate and TeV and X-ray fluxes correlate. However, such
correlated variations have not been explained yet reasonably at this stage.
Assuming that relativistic electrons are injected constantly at the location of
the compact object as a point source, and that they lose energy only by the
inverse Compton (IC) process, we calculate gamma-ray spectra and light curves
by the Monte Carlo method, including the full electromagnetic cascade process.
Moreover, we calculated X-ray spectra and light curves by using the resultant
electron distribution. As a result, we are able to reproduce qualitatively
spectra and light curves observed by HESS, Fermi, and Suzaku for the
inclination angle i = 30 dig and the index of injected electron distribution p
= 2.5. We conclude that TeV-GeV anticorrelation is due to anisotropic IC
scattering and anisotropic gamma-gamma absorption, and that TeV-X correlation
is due to the dependence of IC cooling time on orbital phases. In addition, the
constraint on the inclination angle implies that the compact object in LS5039
is a black hole.Comment: 27 pages, 7 figures, published in The Astrophysical Journa
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