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Papers by J. J. Rodes
El principal objectiu d'aquest treball es mostrar a l'alumnat la varietat de problemes qu... more El principal objectiu d'aquest treball es mostrar a l'alumnat la varietat de problemes que es poden proposar i l'aprenentatge de les estrategies de resolucio de problemes. Amb aquesta finalitat, el llibre s'ha estructurat en questions, exercicis i problemes, amb un nivell creixent de dificultats. El contingut d'aquest llibre correspon a una seleccio dels problemes d'examens que l'autor i el professorat implicat han proposat al llarg dels ultims quinze anys a l'alumnat d'Arquitectura Tecnica i Arquitectura en l'assignatura de Fonaments Fisics. Hem centrat aquesta seleccio en els blocs tematics de Vectors lliscants i Geometria de masses. Finalment, ens trobem en un moment de canvi en la docencia universitaria i hem volgut aprofitar aquesta circumstancia per aplicar algunes caracteristiques del nou model educatiu. Aquesta rao ens ha portat a desenvolupar un apartat especific per a introduir el concepte de problema tipus investigacio i incloure-hi aplicacions d'interes professional"
Revista Mexicana de Astronomía y Astrofísica
The aim of this work is to study both light curve and orbital phase spectroscopy of Cen X-3 takin... more The aim of this work is to study both light curve and orbital phase spectroscopy of Cen X-3 taking advantage of the MAXI/GSC observation strategy. These studies allow delimiting the stellar wind properties and its interactions with the compact object. From the analysis of the light curve, we have estimated the orbital period of the binary system and also found possible QPOs around a superorbital period of Psuperorb = 220 ± 5 days. Both orbital phase-averaged and phaseresolved spectra were extracted and analysed in the 2.0–20.0 keV energy range. Two models have described spectra satisfactorily, a partial absorbed Comptonization of cool photons on hot electrons plus a power law, and a partial absorbed blackbody plus a power law, both modified by adding Gaussian lines. The high value of the X-ray luminosity in the averaged spectrum indicates that the accretion mode is not only due to the stellar wind.
Monthly Notices of the Royal Astronomical Society, 2022
We present the first XMM–Newton observation of the classical supergiant high-mass X-ray binary XT... more We present the first XMM–Newton observation of the classical supergiant high-mass X-ray binary XTE J1855−026 taken entirely during the eclipse of the neutron star (NS), covering the orbital phases ϕ = 0.00–0.11. The analysis of the data allows us to (a) compare with the parameters obtained during the existing pre-eclipse observation and (b) explore the back-illuminated stellar wind of the B0I-type donor. The blackbody component, used to describe the soft excess during pre-eclipse, is not observed during eclipse. It must be then produced near the NS or along the donor–NS line. The 0.3–10 keV luminosity during eclipse (∼1034 erg s−1) is 70 times lower than pre-eclipse. The intensity of the Fe Kα line, in the average eclipse spectrum, is ∼7.4 times lower than the one measured during pre-eclipse. Since Kα photons cannot be resonantly scattered in the wind, the vast majority of Fe Kα emission must come from distances within 1R* from the NS. The eclipse spectrum is successfully modelled t...
Classical Supergiant X-ray Binaries (SGXBs) and Supergiant Fast X-ray Transients (SFXTs) are two ... more Classical Supergiant X-ray Binaries (SGXBs) and Supergiant Fast X-ray Transients (SFXTs) are two types of High-mass X-ray Binaries (HMXBs) that present similar donors but, at the same time, show very different behavior in the X-rays. The reason for this dichotomy of wind-fed HMXBs is still a matter of debate. Among the several explanations that have been proposed, some of them invoke specific stellar wind properties of the donor stars. Only dedicated empiric analysis of the donors' stellar wind can provide the required information to accomplish an adequate test of these theories. However, such analyses are scarce. To close this gap, we perform a comparative analysis of the optical companion in two important systems: IGR J17544-2619 (SFXT) and Vela X-1 (SGXB). We analyse the spectra of each star in detail and derive their stellar and wind properties. We compare the wind parameters, giving us an excellent chance of recognizing key differences between donor winds in SFXTs and SGXBs...
El principal objectiu d'aquest treball es mostrar a l'alumnat la varietat de problemes qu... more El principal objectiu d'aquest treball es mostrar a l'alumnat la varietat de problemes que es poden proposar i l'aprenentatge de les estrategies de resolucio de problemes. Amb aquesta finalitat, el llibre s'ha estructurat en questions, exercicis i problemes, amb un nivell creixent de dificultats. El contingut d'aquest llibre correspon a una seleccio dels problemes d'examens que l'autor i el professorat implicat han proposat al llarg dels ultims quinze anys a l'alumnat d'Arquitectura Tecnica i Arquitectura en l'assignatura de Fonaments Fisics. Hem centrat aquesta seleccio en els blocs tematics de Vectors lliscants i Geometria de masses. Finalment, ens trobem en un moment de canvi en la docencia universitaria i hem volgut aprofitar aquesta circumstancia per aplicar algunes caracteristiques del nou model educatiu. Aquesta rao ens ha portat a desenvolupar un apartat especific per a introduir el concepte de problema tipus investigacio i incloure-hi aplicacions d'interes professional"
Revista Mexicana de Astronomía y Astrofísica
The aim of this work is to study both light curve and orbital phase spectroscopy of Cen X-3 takin... more The aim of this work is to study both light curve and orbital phase spectroscopy of Cen X-3 taking advantage of the MAXI/GSC observation strategy. These studies allow delimiting the stellar wind properties and its interactions with the compact object. From the analysis of the light curve, we have estimated the orbital period of the binary system and also found possible QPOs around a superorbital period of Psuperorb = 220 ± 5 days. Both orbital phase-averaged and phaseresolved spectra were extracted and analysed in the 2.0–20.0 keV energy range. Two models have described spectra satisfactorily, a partial absorbed Comptonization of cool photons on hot electrons plus a power law, and a partial absorbed blackbody plus a power law, both modified by adding Gaussian lines. The high value of the X-ray luminosity in the averaged spectrum indicates that the accretion mode is not only due to the stellar wind.
Monthly Notices of the Royal Astronomical Society, 2022
We present the first XMM–Newton observation of the classical supergiant high-mass X-ray binary XT... more We present the first XMM–Newton observation of the classical supergiant high-mass X-ray binary XTE J1855−026 taken entirely during the eclipse of the neutron star (NS), covering the orbital phases ϕ = 0.00–0.11. The analysis of the data allows us to (a) compare with the parameters obtained during the existing pre-eclipse observation and (b) explore the back-illuminated stellar wind of the B0I-type donor. The blackbody component, used to describe the soft excess during pre-eclipse, is not observed during eclipse. It must be then produced near the NS or along the donor–NS line. The 0.3–10 keV luminosity during eclipse (∼1034 erg s−1) is 70 times lower than pre-eclipse. The intensity of the Fe Kα line, in the average eclipse spectrum, is ∼7.4 times lower than the one measured during pre-eclipse. Since Kα photons cannot be resonantly scattered in the wind, the vast majority of Fe Kα emission must come from distances within 1R* from the NS. The eclipse spectrum is successfully modelled t...
Classical Supergiant X-ray Binaries (SGXBs) and Supergiant Fast X-ray Transients (SFXTs) are two ... more Classical Supergiant X-ray Binaries (SGXBs) and Supergiant Fast X-ray Transients (SFXTs) are two types of High-mass X-ray Binaries (HMXBs) that present similar donors but, at the same time, show very different behavior in the X-rays. The reason for this dichotomy of wind-fed HMXBs is still a matter of debate. Among the several explanations that have been proposed, some of them invoke specific stellar wind properties of the donor stars. Only dedicated empiric analysis of the donors' stellar wind can provide the required information to accomplish an adequate test of these theories. However, such analyses are scarce. To close this gap, we perform a comparative analysis of the optical companion in two important systems: IGR J17544-2619 (SFXT) and Vela X-1 (SGXB). We analyse the spectra of each star in detail and derive their stellar and wind properties. We compare the wind parameters, giving us an excellent chance of recognizing key differences between donor winds in SFXTs and SGXBs...