Papers by Author: R. Leticia Corral-Bustamante

Abstract: In view of the fact that X-ray sources present characteristic spectra that make them unique, the spectral fitting technique has proven to play a fundamental role through the use of models that make it possible to reproduce the observed spectrum, thus making it possible to characterize the type of source that gave rise to it. A tool of paramount importance, among others that are currently gaining ground, is the XSPEC software, which is a solid and stable spectral fitting package that allows us to conduct scientific work with high standards of rigor in the analysis of data from astronomical objects in whose processes high energies are intrinsically involved, as is the case of X-rays. In this work we fit and analyze experimental data of two X-ray binary spectra: Cyg X-1 and V 0332+53, with theoretical models in XSPEC to obtain the expected statistics of the best fit through the reduced chi-square (hereafter, χ²) in both astronomical sources. From the results, it can be concluded that in both sources the best fit representing the physical processes occurring in these binaries was achieved, very close to results obtained by other authors using different techniques, contributing to the state of the art of the spectrum of astrophysical processes of high energy binaries.

Abstract: Is it possible to quantify in General Relativity, GR, the entropy generated by Super-Massive Black Holes, SMBH, during its evaporation time, since the intrinsic Hawking radiation in the infinity that, although insignificant, is important in the effects on the thermal quantum atmosphere? The purpose was to develop a formula that allows us to measure the entropy generated during the evaporation time of different types of SMBH of: i. remnant BH of the binary black holes’ merger, BBH: GW150914, GW151226 and LTV151012 detected by the Laser Interferometer Gravitational-Wave Observatory, LIGO, and ii. Schwarzschild, Reissner-Nordström, Kerr and Kerr-Newman, and thus quantify in GR the “insignificant” quantum effects involved, in order to contribute to the validity of the generalized second law, GSL, that directly links the laws of black hole mechanics to the ordinary laws of thermodynamics, as a starting point for unifying quantum effects with GR. This formula could have some relationship with the detection of the shadow’s image of the event horizon of a BH. This formula was developed in dimensional analysis, using the constants of nature and the possible evaporation time of a black hole, to quantify the entropy generated during that time. The energy-stress tensor was calculated with the 4 metrics to obtain the material content and apply the proposed formula. The entropy of the evaporation time of SMBH proved to be insignificant, its temperature is barely above absolute zero, however, the calculation of this type of entropy allows us to argue about the importance of the quantum effects of Hawking radiation mentioned by authors who have studied the quantum effects with arguments that are fundamentally based on the presence of the surrounding thermal atmosphere of the BH.

Abstract: A new approach to evaluate the Newtonian flow between concentric rotating spheres is introduced in this paper. A general analytic solution to the problem is deduced using a perturbation method that takes into account the primary and secondary flows produced between the spheres, as well as an alternative analytical method. In order to exemplify the results of the previous analysis, six particular cases were studied. The results of the perturbation method show that under certain circumstances the secondary flow is no negligible, as is usually considered, but it is comparable to the value of the primary one. While the analytical method allows us to simulate the flow with results very similar to those of other authors.