Talk detail

Participant	Rueda Hernandez, Jorge Armando
Institution	ICRANet - Piazza della Repubblica 10 - Pescara - Abruzzo - Italy

Session	NS5	Accepted	Yes	Order	6	Time	17:30	25' + 5'
Talk	Oral abstract	Title	SGRs and AXPs as Rotation-Powered Compact Stars
Coauthors	Cáceres, D. L.; Camargo, R.; Coelho, J. G.; Malheiro, M.; R. Ruffini
Abstract	We show that nine of the twenty three soft gamma repeaters (SGRs) and anomalous X-ray pulsars (AXPs), namely the 40\% of the observed population, can be described as canonical pulsars driven by the rotational energy of a neutron star. We give the possible range of the neutron star mass for which this is possible and for selected nuclear equations of state. We show that the energetics of the bursts emitted by these sources can be explained via the rotational energy gained during glitches, for which we predict the fractional change of rotation period and compare with observations, where available. Assuming on the other hand an alternative scenario in which SGR/AXPs are rotation-powered white dwarfs, we compute tight constraints for the masses, radii, and magnetic field of the white dwarf by requesting the gravitational and rotational stability of the star. We discuss the consistency of the above white dwarf parameters through the observations in the X and optical wavelengths.
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Session	PS	Accepted		Order		Time
Talk	Oral abstract	Title	The binary systems associated to short and long GRBs and their detectability
Coauthors	Ruffini, R; Muccino, M.; Oliveira, F. G.
Abstract	There is increasing theoretical and observational evidence on the binary nature of the progenitors of short and long-duration gamma-ray bursts (S-GRBs and L-GRBs, respectively). For S-GRBs, possible progenitors are mergers of double neutron stars (DNSs) or NS-black hole (NS-BH) binaries. For L-GRBs, the induced gravitational collapse paradigm proposes a tight binary system composed of a carbon-oxygen (CO) core which undergoes supernova (SN) creating a massive accretion process onto a NS companion. These latter events have been called binary-driven hypernovae (BdHNe). BdHNe might lead either to a new DNS or to a NS-BH binary, the latter formed if the accretion is sufficient to bring the NS to its critical mass for the gravitational collapse to a BH. I shall discuss: 1) the role of the NS structure and the equation of state on the final fate of all the above binaries; 2) the local observed rates of these events by X and gamma-ray instruments; 3) the expected number of detections by second-generation gravitational wave (GW) detectors. I shall show that the merger of DNSs, formed in BdHNe, constitute a promising source of detectable GWs by Advanced LIGO, not accounted for in current DNS population synthesis analyses.
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