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Date: 5-9-2020
1259
Date: 11-8-2020
1373
Date: 28-8-2020
1840
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The stellar collider in the Galactic Center
The potential for probing a new regime of stellar dynamics near the MBH in the Galactic Center is best illustrated by comparing the collisional timescale there with that in the cores of the densest globular clusters, which for a long time served as laboratories for the study of collisional processes. In a dense globular cluster, n* ∼ 106 Mּ pc−3 and σ ∼ 10 km s−1, whereas in the Galactic Center, the density may be as high as n* ∼ 108 Mּ pc−3 and σ ∼ 1000 km s−1. The timescale for collisions between solar-type stars in a globular cluster can be estimated to be almost 1010 yr, roughly the age of the Galaxy and of a solar-type star, whereas it is only ∼5×108 yr in the inner 0.02 pc of the Galactic Center. These estimates imply that while physical collisions are only marginally relevant in the cores of the densest globular clusters, they completely dominate the dynamics in the innermost part of the MBH cusp.
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تفوقت في الاختبار على الجميع.. فاكهة "خارقة" في عالم التغذية
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أمين عام أوبك: النفط الخام والغاز الطبيعي "هبة من الله"
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المجمع العلمي ينظّم ندوة حوارية حول مفهوم العولمة الرقمية في بابل
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