1 research outputs found
On the X-ray Emission from Massive Star Clusters and their Evolving Superbubbles
The X-ray emission properties from the hot thermalized plasma that results
from the collisions of individual stellar winds and supernovae ejecta within
rich and compact star clusters are discussed. We propose a simple analytical
way of estimating the X-ray emission generated by super star clusters and
derive an expression that indicates how this X-ray emission depends on the main
cluster parameters. Our model predicts that the X-ray luminosity from the star
cluster region is highly dependent on the star cluster wind terminal speed, a
quantity related to the temperature of the thermalized ejecta.We have also
compared the X-ray luminosity from the SSC plasma with the luminosity of the
interstellar bubbles generated from the mechanical interaction of the high
velocity star cluster winds with the ISM.We found that the hard (2.0 keV - 8.0
keV) X-ray emission is usually dominated by the hotter SSC plasma whereas the
soft (0.3 keV - 2.0 keV) component is dominated by the bubble plasma. This
implies that compact and massive star clusters should be detected as point-like
hard X-ray sources embedded into extended regions of soft diffuse X-ray
emission. We also compared our results with predictions from the population
synthesis models that take into consideration binary systems and found that in
the case of young,massive and compact super star clusters the X-ray emission
from the thermalized star cluster plasma may be comparable or even larger than
that expected from the HMXB population.Comment: 24 pages, 8 figures, Accepted for publication in The Astrophysical
Journa