Aims. Emission lines in polars show complex profiles with multiple components that are typically ascribed to the accretion stream, threading region, accretion spot, and the irradiated secondary-star. In low-state polars the fractional contribution by the accretion stream, and the accretion spot is greatly reduced offering an opportunity to study the effect of the secondary-star irradiation or s...

In this poster I discuss the nature of the compact X-ray source in the center of the supernova remnant RCW 103. Several models, based on the accretion onto a compact object such as a neutron star or a black hole (isolated or binary), are analyzed. I show that it is more likely that the central X-ray source is an accreting neutron star than an accreting black hole. I also argue that models of a ...

In this work we will explore the theoretical connections existing between fuzzy rule-based systems (FRBS) applied on univariate time series and two statistical reference tools, the autoregressive (AR) models and the smooth transition autoregressive (STAR) model. We will show that a TSK fuzzy rule happens to be a localised AR model and that a STAR model can hence be interpreted as a restricted F...

A long standing problem with asymptotic giant branch (AGB) star models has been their inability to produce the low-luminosity carbon stars in the Large and Small Magellanic Clouds. Dredge-up must begin earlier and extend deeper. We find this for the first time in our models of LMC metallicity. Such features are not found in our models of SMC metallicity. The fully implicit and simultaneous stel...

We use the definition of complexity for static and self– gravitating objects to build up three physical general relativistic anisotropic models fulfilling vanishing condition which serves provide extra information needed close system Einstein field equations. evaluate acceptability these by testing some conditions that geometric material sector must satisfy in order be considered as reasonable ...

The observed association of Long GammaRay Bursts (LGRBs) with peculiar Type Ic supernovae gives support to Woosley‘s collapsar/hypernova model, in which the GRB is produced by the collapse of the rapidly rotating core of a massive star to a black hole. The association of LGRBs with small starforming galaxies suggests low-metallicity to be a condition for a massive star to evolve to the collapsa...