A one-parameter family of interpolating kernels for Smoothed Particle Hydrodynamics studies

A set of interpolating functions of the type f(v)={(sin[v pi/2])/(v pi/2)}^n is analyzed in the context of the smoothed-particle hydrodynamics (SPH) technique. The behaviour of these kernels for several values of the parameter n has been studied either analytically as well as numerically in connection with several tests carried out in two dimensions. The main advantage of this kernel relies in its flexibility because for n=3 it is similar to the standard widely used cubic-spline, whereas for n>3 the interpolating function becomes more centrally condensed, being well suited to track discontinuities such as shock fronts and thermal waves.Comment: 36 pages, 12 figures (low-resolution), published in J.C.

The INTEGRAL-OMC Scientific Archive

The Optical Monitoring Camera (OMC) on-board the INTEGRAL satellite has, as one of its scientific goals, the observation of a large number of variable sources previously selected. After almost 6 years of operations, OMC has monitored more than 100 000 sources of scientific interest. In this contribution we present the OMC Scientific Archive (http://sdc.laeff.inta.es/omc/) which has been developed to provide the astronomical community with a quick access to the light curves generated by this instrument.We describe the main characteristics of this archive, as well as important aspects for the users: object types, temporal sampling of light curves and photometric accuracy.Comment: 4 pages, 5 figures. "Highlights of Spanish Astrophysics V" Proceedings of the VIII Scientific Meeting of the Spanish Astronomical Society (SEA) held in Santander, July 7-11, 200

High temperature combustion: Approaching equilibrium using nuclear networks

A method for integrating the chemical equations associated with nuclear combustion at high temperature is presented and extensively checked. Following the idea of E. M\"uller, the feedback between nuclear rates and temperature was taken into account by simultaneously computing molar fraction changes and temperature response in the same matrix. The resulting algorithm is very stable and efficient at calculating nuclear combustion in explosive scenarios, especially in those situations where the reacting material manages to climb to the nuclear statistical equilibrium regime. The numerical scheme may be useful not only for those who carry out hydrodynamical simulations of explosive events, but also as a tool to investigate the properties of a nuclear system approaching equilibrium through a variety of thermodynamical trajectories.Comment: 31 pages, 11 figures, accepted for publication in the ApJ

Detailed Spectral Modeling of a 3-D Pulsating Reverse Detonation Model: Too Much Nickel

We calculate detailed NLTE synthetic spectra of a Pulsating Reverse Detonation (PRD) model, a novel explosion mechanism for Type Ia supernovae. While the hydro models are calculated in 3-D, the spectra use an angle averaged hydro model and thus some of the 3-D details are lost, but the overall average should be a good representation of the average observed spectra. We study the model at 3 epochs: maximum light, seven days prior to maximum light, and 5 days after maximum light. At maximum the defining Si II feature is prominent, but there is also a prominent C II feature, not usually observed in normal SNe Ia near maximum. We compare to the early spectrum of SN 2006D which did show a prominent C II feature, but the fit to the observations is not compelling. Finally we compare to the post-maximum UV+optical spectrum of SN 1992A. With the broad spectral coverage it is clear that the iron-peak elements on the outside of the model push too much flux to the red and thus the particular PRD realizations studied would be intrinsically far redder than observed SNe Ia. We briefly discuss variations that could improve future PRD models.Comment: 15 pages, 4 figures, submitted to Ap

Gravitational waves as tracers of nuclear equation of state

The signal of neutron star (NS) mergers has the imprint of the EOS of dense nuclear matter, which is still not well known. A set of gravitational waves (GW) signals have been calculated from 3D hydrodynamical simulations of NS-NS mergers using the Smoothed Particle Hydrodynamics technique (SPH) with different EOS. By analyzing the morphology and time evolution of the signal we want to be able to discriminate among the variety of proposed EOS after a successful GW detection has been done

Are nursing students trained to meet the needs of cancer survivors and their families? New challenges, new opportunities

Current cancer treatments, along with more effective prevention measures, are producing increased cancer survival globally;(1) becoming – in many cases – a chronic disease.(2) Care of patients and families, living with a chronic disease, like cancer, constitutes one of the principal challenges for most health systems because they represent a heavy burden in terms of morbidity and mortality and carry a high percentage of the public expenditure in health.(3) Above all, the impact of cancer entails suffering and represents an important limitation in the quality of life, productivity, and functional state of the sick individuals and those living with them, that is, their family. More so, with evidence of the progressive increase of the number of older people with cancer, who are more prone to having comorbidities and other problems associated with their age, like dementia, depression, cerebrovascular accident, and diabetes

Observations of SN2011fe with INTEGRAL

SN2011fe was detected by the Palomar Transient Factory on August 24th 2011 in M101 few hours after the explosion. From the early spectra it was immediately realized that it was a Type Ia supernova thus making this event the brightest one discovered in the last twenty years. In this paper the observations performed with the instruments on board of INTEGRAL (SPI, IBIS/ISGRI, JEM-X and OMC) before and after the maximum of the optical light as well as the interpretation in terms of the existing models of $\gamma$--ray emission from such kind of supernovae are reported. All INTEGRAL high-energy have only been able to provide upper limits to the expected emission due to the decay of $^{56}$Ni. These bounds allow to reject explosions involving a massive white dwarf in the sub--Chandrasekhar scenario. On the other hand, the optical light curve obtained with the OMC camera suggests that the event was produced by a delayed detonation of a CO white dwarf that produced $\sim 0.5$ M$\odot$ of $^{56}$Ni. In this particular case, INTEGRAL would have only been able to detect the early $\gamma$--ray emission if the supernova had occurred at a distance of 2 -3 Mpc, although the brightest event could be visible up to distances larger by a factor two.Comment: Proceedings of "An INTEGRAL view of the high-energy sky (the first 10 years)" the 9th INTEGRAL Workshop, October 15-19, 2012, Paris, France, in Proceedings of Science (INTEGRAL 2012), Eds. A. Goldwurm, F. Lebrun and C. Winkler, http://pos.sissa.it/cgi-bin/reader/conf.cgi?confid=176, id number PoS (INTEGRAL 2012) 103 (2013

Observation of SN2011fe with INTEGRAL. I. Pre--maximum phase

SN2011fe was detected by the Palomar Transient Factory on August 24th 2011 in M101 a few hours after the explosion. From the early optical spectra it was immediately realized that it was a Type Ia supernova thus making this event the brightest one discovered in the last twenty years. The distance of the event offered the rare opportunity to perform a detailed observation with the instruments on board of INTEGRAL to detect the gamma-ray emission expected from the decay chains of $^{56}$Ni. The observations were performed in two runs, one before and around the optical maximum, aimed to detect the early emission from the decay of $^{56}$Ni and another after this maximum aimed to detect the emission of $^{56}$Co. The observations performed with the instruments on board of INTEGRAL (SPI, IBIS/ISGRI, JEMX and OMC) have been analyzed and compared with the existing models of gamma-ray emission from such kind of supernovae. In this paper, the analysis of the gamma-ray emission has been restricted to the first epoch. Both, SPI and IBIS/ISGRI, only provide upper-limits to the expected emission due to the decay of $^{56}$Ni. These upper-limits on the gamma-ray flux are of 7.1 $\times$ 10$^{-5}$ ph/s/cm$^2$ for the 158 keV line and of 2.3 $\times$ 10$^{-4}$ ph/s/cm$^2$ for the 812 keV line. These bounds allow to reject at the $2\sigma$ level explosions involving a massive white dwarf, $\sim 1$ M$\odot$ in the sub--Chandrasekhar scenario and specifically all models that would have substantial amounts of radioactive $^{56}$Ni in the outer layers of the exploding star responsible of the SN2011fe event. The optical light curve obtained with the OMC camera also suggests that SN2011fe was the outcome of the explosion, possibly a delayed detonation although other models are possible, of a CO white dwarf that synthesized $\sim 0.55$ M$_\odot$ of $^{56}$Ni. For this specific model.Comment: Accepted for publication in A&A. 10 pages, 10 figure

Emergence of communities on a coevolutive model of wealth interchange

We present a model in which we investigate the structure and evolution of a random network that connects agents capable of exchanging wealth. Economic interactions between neighbors can occur only if the difference between their wealth is less than a threshold value that defines the width of the economic classes. If the interchange of wealth cannot be done, agents are reconnected with another randomly selected agent, allowing the network to evolve in time. On each interaction there is a probability of favoring the poorer agent, simulating the action of the government. We measure the Gini index, having real world values attached to reality. Besides the network structure showed a very close connection with the economic dynamic of the system.Comment: 5 pages, 7 figure