Talk detail

Participant	Rueda Hernandez, Jorge Armando
Institution	ICRANet and Sapienza University of Rome - Piazzale Aldo Moro 5 - Rome - Lazio - Italy

Session	SN3	Accepted		Order	Time
Talk	Oral abstract	Title	Delayed Gravitational Collapse of General Relativistic Uniformly Rotating Super Chandrasekhar White Dwarfs
Co-authors
Abstract	Constant-mass sequences of general relativistic uniformly rotating white dwarfs (WDs) are computed within the Hartle’s formalism. For the description of the WD matter, we use the relativistic Feynman-Metropolis-Teller EoS that generalizes the one of Salpeter. The stability of Super Chandrasekhar WDs (SChWDs) constrain their angular momentum between a minimum non-zero value and an upper bound that are determined by the mass-shedding, secular, and inverse beta decay instabilities. We show that SChWDs spin up by losing angular momentum regardless of their chemical composition and so the misalignment of the dipole magnetic moment and the rotation axis makes SChWDs to spin up with time, and eventually reach one of the instability boundaries. We compute the lifetime of SChWDs and discussed the consequences on delayed time SN Ia population.

Session	SF2	Accepted		Order	Time
Talk	Oral abstract	Title	Using Gamma Ray Bursts to constrain the theory of compact stars
Co-authors
Abstract

Session	SN1	Accepted		Order	Time
Talk	Oral abstract	Title	On the Induced Gravitational Collapse of a Neutron Star to a Black Hole by a Type Ib/c Supernova
Co-authors
Abstract	It is understood that the Supernovae (SNe) associated to Gamma Ray Bursts (GRBs) are of type Ib/c. The temporal coincidence of the GRB and the SN represents still a major enigma of Relativistic Astrophysics. We elaborate here, from the earlier paradigm, that the concept of induced gravitational collapse is essential to explain the GRB-SN connection. The specific case of a close (period $<1$ h) binary system composed of an evolved C+O core with a neutron star companion is considered. We evaluate the accretion rate onto the neutron star when the C+O star explodes as a type Ib/c SN and the explicit expression of the accreted mass as a function of the nature of the components and binary parameters is given. We show that the neutron star can reach, in a few seconds, the critical mass and consequently gravitationally collapses to a black hole. This gravitational collapse process leads to the emission of the GRB.