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تسجيل مستخدم جديدFormation Efficiencies of Old Globular Clusters - from Dwarf to Giant Galaxies
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For the full galaxy mass range, we find that previously observed trends of globular cluster (GC) system scaling parameters (number, luminosity or mass of all GCs in a galaxy normalized to the host galaxy luminosity or mass, e.g. S_L) as a function of galaxy mass, holds irrespective of galaxy type or environment. The S_L-value of early-type galaxies is, on average, twice that of late-types. We derive theoretical predictions which describe remarkably well the observed GC system scaling parameter distributions given an assumed GC formation efficiency ({eta}), i.e. the ratio of total mass in GCs to galaxy halo mass. It has a mean value of {eta}=5.5e-5 , and an increasing scatter toward low galaxy mass. The excess {eta}-values of some massive galaxies compared to expectations from the mean model prediction, may be attributed to an efficient GC formation, inefficient production of field stars, accretion of low-mass high-{eta} galaxies or likely a mixture of all these effects.
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