1,721,027 research outputs found
Multimass King models with Kroupa mass function
Full text linkMultimass models for globular clusters are introduced by using Kroupa mass function. These
models generalize the single mass King models presented last year in “XII Multifrequency Be-
haviour of High Energy Cosmic Sources Workshop” (2017), where the thermodynamical insta-
bility of such models was also discussed. Observational profiles of surface brightness of some
clusters are compared and contrasted with the theoretical predictions in new and old models. Ef-
fects of mass segregation on the distribution of stars and the consequences on the equipartition of
the energy among the stars are also considered, implying different conclusions about the thermo-
dynamical instability
La figura del ricercatore universitario e il DDL Moratti sullo stato giuridico dei professori universitari
No full textNessun abstract
Relativistic stellar clusters
Full text linkStar clusters with very high densities may play an important role in QSO and nuclei of galaxies. This role is strongly influenced by relativistic instability which can be reached at different critical densities under particular conditions (e.g. the formation of massive black holes in AGN's). On the other hand it exists the possibility to have stable relativistic clusters with arbitrarily large central redshift (and
density). The equilibrium and stability of relativistic clusters described by a Maxwellian distribution function with a cutoff in phase space is discussed. The results are compared and contrasted with ones existing in literature
The semidegenerate configurations of a selfgravitating system of fermions
Full text linkIt is shown how the semi-degenerate solution of a self-gravitating system treated by a series expansion around the fully degenerate values is critical in the low-density regimes, where the distribution function is far from the degenerate one. The results based on a first- and second-order expansion are compared and contrasted with the exact ones
Chi ha paura del ruolo unico?
No full textMarco Merafina (Roma, 29.5.1959) è ricercatore universitario dal 1992. Lavora come astrofisico presso il dipartimento di Fisica della facoltà di Scienze matematiche fisiche e naturali all’università di Roma “La Sapienza”. Il suo campo di ricerca è la dinamica stellare
e lo studio dei sistemi astrofisici ad alta densità in regime di relatività generale. Dal 2003 è rappresentante dei ricercatori nel consiglio
di amministrazione della Sapienza ed attualmente è coordinatore nazionale dei ricercatori universitari (CNRU)
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