The HI Distribution Observed toward a Halo Region of the Milky Way

We use observations of the neutral atomic hydrogen (HI) 21-cm emission line to study the spatial distribution of the HI gas in a 80$\degree\times~$90$\degree$ region of the Galaxy halo. The HI column densities in the range of \mbox{3--11$\times$10$^{20}$ cm$^{-2}$} have been estimated for some of the studied regions. In our map---obtained with a spectral sensitivity of $\sim$2 K---we do not detect any HI 21-cm emission line {above 2$\sigma$} at Galactic latitudes higher than $\sim${46}$\degree$. {This report summarizes our contribution presented at the conference on the origin and evolution of barionic Galaxy halos}

Upper Limits to Magnetic Fields in the Outskirts of Galaxies

Based on CO(2-1) public data, we study the monoxide oxygen gas excitation conditions and the magnetic field strength of four spiral galaxies. For the galaxy outskirts, we found kinetic temperatures in the range of $\lesssim$35--38 K, CO column densities $\lesssim 10^{15}$--$10^{16}$ cm$^{-2}$, and H$_2$ masses $\lesssim 4\times 10^6$--$6\times10^8$ M$_\odot$. An H$_2$ density $\lesssim 10^3$ cm$^{-3}$ is suitable to explain the 2$\sigma$ upper limits of the CO(2-1) line intensity. We constrain the magnetic field strength for our sample of spiral galaxies and their outskirts by using their masses and H$_2$ densities to evaluate a simplified magneto-hydrodynamic equation. Our estimations provide values for the magnetic field strength on the order of $\lesssim$6--31 {\upmuG}

Circular geodesics stability in a static black hole in new massive gravity

We study the existence and stability of circular geodesics in a family of asymptotically AdS static black holes in New Massive Gravity theory. We show that the mathematical sign of the hair parameter determines the existence of such geodesics. For a positive hair parameter, the stability regions follow the usual pattern, with the innermost geodesic being null, unstable, and separated from the horizon, followed by a region of unstable timelike geodesics and then a region of stable timelike geodesics, which extends in the asymptotic region.Fil: Aceña, Andrés Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; ArgentinaFil: López, Ericson. Escuela Politécnica Nacional; EcuadorFil: Aldás, Franklin. Escuela Politécnica Nacional; Ecuado

A further analysis for galactic dark matter halos with pressure

Spherically symmetric and static dark matter halos in hydrostatic equilibrium demand that dark matter should have an effective pressure that compensates the gravitational force of the mass of the halo. An effective equation of state can be obtained for each rotational velocity profile of the stars in galaxies. In this work, we study one of this dark matter equation of state obtained for the Universal Velocity Profile and analyze the properties of the self-gravitating structures that emerges from this equation of state. The resulting configurations explaining the observed rotational speeds are found to be unstable. We conclude that either the halo is not in hydrostatic equilibrium,or it is non spherically symmetric, or it is not static if the Universal Velocity profile should be valid to fit the rotational velocity curve of the galaxies.Fil: Aceña, Andrés Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; ArgentinaFil: Barranco, Juan. Universidad de Guanajuato; MéxicoFil: Bernal, Argelia. Universidad de Guanajuato; MéxicoFil: López, Ericson. Escuela Politécnica Nacional; EcuadorFil: Llerena, Mario. Universidad de La Serena; Chil

The Bonsai as an alternative safety duplication system of the world cassava collection preserved at CIAT

The germplasm bank of CIAT houses more than 6,000 accessions of cassava (Manihot esculenta Crantz) constituting the most important collection for this crop. In order to guarantee the safety of the materials, the collection has an international duplicate kept at the International Potato Center (CIP) in Peru under in vitro conditions. However, due to the difficulties in having this system of duplication sustained for long periods of time, it was decided to keep the backup on a slow-growth scheme under greenhouse conditions. In vitro plants must undergo a hardening or acclimatization phase of approximately four weeks, which takes into account factors such as substrate, control of environmental conditions and pathogens to prevent loss of material. In this work, the use of a methodology for the establishment of materials in greenhouse was evaluated and compared with four systems previously used for this purpose. Modification in the substrate, the use of a biological inoculant, moist chamber conditions and fertilization allowed the establishment of 1,818 accessions with a loss rate of less than 4%, compared to the initial number of plants (1,886) which indicates that the methodology evaluated is adequate for their hardening. The plants were obtained from the in vitro cassava collection and were tested and found free from three diseases considered of quarantine for the Americas: Cassava common mosaic virus, Cassava frogskin agent and Cassava virus “X”. These materials have also been tested and found to be free of Reovirus, Luteovirus, Torradovirus and Potexvirus. The bonsai copy allows to safeguard a greater percentage of accessions for prolonged periods, since, by restricting the growth of the root in plastic containers and with controlled prunings, it is possible to maintain the plants for more than two years, time greater than achieved with the duplication systemwith in vitro techniques

Vector-meson magnetic dipole moment effects in radiative tau decays

We study the possibility that the magnetic dipole moment of light charged vector mesons could be measured from their effects in \tau^- --> V^-\nu_{\tau}\gamma decays. We conclude that the energy spectrum and angular distribution of photons emitted at small angles with respect to vector mesons is sensitive the effects of the magnetic dipole moment. Model-dependent contributions and photon radiation off other electromagnetic multipoles are small in this region. We also compute the effects of the magnetic dipole moment on the integrated rates and photon energy spectrum of these $\tau$ lepton decays.Comment: Latex, 12 pages, 4 figures, submitted to PR