The dark matter profile of the Milky Way: a non-parametric reconstruction

We present the results of a new, non-parametric method to reconstruct the Galactic dark matter profile directly from observations. Using the latest kinematic data to track the total gravitational potential and the observed distribution of stars and gas to set the baryonic component, we infer the dark matter contribution to the circular velocity across the Galaxy. The radial derivative of this dynamical contribution is then estimated to extract the dark matter profile. The innovative feature of our approach is that it makes no assumption on the functional form or shape of the profile, thus allowing for a clean determination with no theoretical bias. We illustrate the power of the method by constraining the spherical dark matter profile between 2.5 and 25 kpc away from the Galactic center. The results show that the proposed method, free of widely used assumptions, can already be applied to pinpoint the dark matter distribution in the Milky Way with competitive accuracy, and paves the way for future developments.

Planet formation in a triple stellar system: implications of the third star's orbital inclination

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Free massive particles with total energy E

We analyze free elementary particles with a rest mass m and total energy Estars, and use Unruh-DeWitt-like detectors to calculate the associated particle detection rate in each case. The (mean) particle position is identified with the spatial average of the excitation probability of the detectors, which are supposed to cover the whole space. Our results are shown to be in harmony with general relativity classical predictions. Eventually we reconcile our conclusions with Earth-based experiments which are in good agreement with E ≥mc2.

Is SAX J1808.4-3658 a Strange Star?

The possibility of strange stars is one of the most important issues in the study of compact objects. Here we use the observations of the newly discovered millisecond x-ray pulsar SAX J1808.4-3658 to constrain the radius of the compact star. Comparing the mass-radius relation of SAX J1808.4-3658 with theoretical models for both neutron stars and strange stars, we argue that a strange star model could be more consistent with SAX J1808.4-3658, and suggest that it is a likely strange star candidate. Our results are useful in constraining microscopic chiral symmetry restoration parameters in the quantum chromodynamics (QCD) modeling of strange matter.

Medium effects in the pion-pole mechanism [gamma gamma ->pi(0)->nu(R)(nu)over-bar(L)(nu(L)(nu)over-bar(R))] of neutron star cooling

Nuclear medium effects in the neutrino cooling of neutron stars through the reaction channel γγ→π0 →ν Rν̄L(νLν̄R) are incorporated. Throughout the paper we discuss different possibilities of right-handed neutrinos, massive left-handed neutrinos, and standard massless left-handed neutrinos (reaction is then allowed only with medium modified vertices). It is demonstrated that multiparticle effects suppress the rate of this reaction channel in the dense hadron matter by 6-7 orders of magnitude that does not allow to decrease existing experimental upper limit on the corresponding π0νν̄ coupling. Other possibilities of the manifestation of the given reaction channel in different physical situations, e.g., in the quark color superconducting cores of the most massive neutron stars, are also discussed. We demonstrate that in the color-flavor-locked superconducting phase for temperatures T≲ 0.1-10 MeV (depending on the effective pion mass and the decay width) the process is feasibly the most efficient neutrino cooling process, although the absolute value of the reaction rate is rather small.

Influxos do céu na existência dos homens. Os escritos astrológicos na Península Ibérica (séculos XIII, XIV e XV)

Pós-graduação em História - FCHS

Caixa experimentoteca: uma proposta para o ensino de astronomia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Produção do monóxido de titânio em estrelas variáveis

Mira are pulsating variable stars in advanced stages of evolution. Their atmospheres are sources of intense absorption bands attributed to molecular titanium monoxide (TiO). It has been suggested that the abundance of TiO reaches its maximum value near the minimum light. In this sense, the study of the processes of formation and destruction of TiO in circumstellar envelopes of Mira stars, not only allows us to understand the physical and chemical processes that occur in these environments, as it allows to verify the correlation between the abundance of TiO and its light curve. However, the main mechanisms of formation and destruction of TiO are poorly known and, consequently, the possible correlation between the abundance of this species and the light curve. In these sense, we studied the main processes of formation and destruction of titanium monoxide in molecular layers of Mira atmospheres and determined its temporal variation as function of the stellar radius. The TiO profile along the radius was expected for the different stellar phase, however its abundance is not enough to explain the light curve. The reasons behind it are discussed in details

Apoptose em placentônios bovinos de gestações de conceptos naturais e de transgênicos clonados

Pós-graduação em Ciência e Tecnologia Animal - FEIS

Políticas e desenvolvimento do estado de Mato Grosso após abertura comercial: análise da visão de dois empresários atuantes no setor

After realizing two interviews, with distinct managers/businessmen working in the cotton industry, the objective is to put in evidence the political, economical and social factors that contributed to the formation and configuration of the Mato Grosso state, after the trade liberalization that occurred in the early 90's, it's effects and consequences in the eyes of the interviewed. The study of public policies is primordial to the discovery of the configuration of determined place, evaluating advances and possible errors in the social, economical and environmental areas. Through the analysis of the interviews it has been found that the urban centers have been developing with a direct link to the industrial activities related to agriculture and that the labor work force have also been attracted because of these changes, and as a consequence this labor force is now becoming more specialized to be able to accompany the jobs requirements in the industry. Analyzing the interviews, it is possible to highlight some information about the development of Mato Grosso, among those the following factors and public policies. The creation and expansion of the cities in the state are possible through public and private investment in infrastructure the socioeconomic development of the state is linked with the advances made in the private sector that grows because of advances made in crops technology in contrast to the occupation of the cerrado, in relation to the cotton crops. The problems that Mato Grosso is facing are mainly linked to the region infrastructure, that can count on investment plans to transportation and production flow that dates before the globalization era. The pattern that is seen today with top of the line agricultural production, big monoculture with high productivity and the arrival of multinational giants, was implanted because of two important events: the trade liberalization in the 1990's and the cambial depreciation in the 1999's...