Mass Loss from Stars and the Evolution of Stellar Clusters
نویسندگان
چکیده
New NTT/SOFI near-IR narrow-band imaging and spectroscopy reveals an additional four Wolf-Rayet (WR) stars in the massive cluster Westerlund 1, bringing the total WR population to 24. Sixteen of the WR stars in Wd1 have been classified WN5–11, while eight are WC8–9. An observed WR to RSG/YHG ratio of ∼3 suggests an age of 4.5–5.0 Myr, with WR stars descended from 40–55M⊙ progenitors. On the basis of dust and hard X-ray emission, we estimate that 40–65% are probable members of massive star binary systems.
منابع مشابه
Scaling relations in dynamical evolution of star clusters
We have carried out a series of small scale collisional N-body calculations of single-mass star clusters to investigate the dependence of the lifetime of star clusters on their initial parameters. Our models move through an external galaxy potential with a logarithmic density profile and they are limited by a cut-off radius. In order to find scaling relations between the lifetime of star cluste...
متن کاملPulsating red giant and supergiant stars in the Local Group dwarf galaxy Andromeda I
We have conducted an optical long-term monitoring survey of the majority of dwarf galaxies in the Local Group, with the Isaac Newton Telescope (INT), to identify the long period variable (LPV) stars. LPV stars vary on timescales of months to years, and reach the largest amplitudes of their brightness variations at optical wavelengths, due to the changing temperature. They trace stellar populati...
متن کاملForty Years of X-Ray Binaries
In 2012 it was forty years ago that the discovery of the first X-ray binary Centaurus X-3 became known. That same year it was discovered that apart from the High-Mass X-ray Binaries (HMXBs) there are also Low-Mass X-ray Binaries (LMXBs), and that Cygnus X-1 is most probably a black hole. By 1975 also the new class of Be/X-ray binaries was discovered. After this it took 28 years before ESAs INTE...
متن کاملTHE EFFECT OF COSMIONS ON THE STABILITY OF MAIN SEQUENCE STELLAR CORES
We have studied the effect of hypothetical Cosmions on the core stability of main sequence stars (of populations I and II). Cosmions, with a mass of 4-10 Gev/c2 and a scattering cross section with nucleons of approximately 10-36 cm2 could prevail in transporting heat in the stellar cores. Raby [17] showed the existence of a local thermal instability caused by the presence of Cosmions in the sol...
متن کاملStellar-Dynamics of Young Star Clusters
The stellar-dynamical evolution of bound star clusters during the first few Myr is dominated by binary-binary and binary-star interactions, the rapid sinking of the most massive stars to the centre of the clusters and mass loss from evolving stars. The consequences of these processes for the binary and stellar population in clusters, and for the star clusters as a whole, are studied by followin...
متن کاملThe photometric evolution of star clusters and the preferential loss of low - mass bodies - with an application to globular clusters ⋆
The photometric evolution of star clusters and the preferential loss of low-mass bodies-with an application to globular clusters ⋆ ABSTRACT Context. To obtain an accurate description of broad-band photometric star cluster evolution, certain effects should be accounted for. Energy equipartition leads to mass segregation and the preferential loss of low-mass stars, while stellar remnants severely...
متن کامل