21 research outputs found
Super star clusters and Supernovae in interacting LIRGs unmasked by NIR adaptive optics
We report on an on-going near-IR adaptive optics survey targeting interacting
luminous IR galaxies. High-spatial resolution NIR data are crucial to enable
interpretation of kinematic, dynamical and star formation (SF) properties of
these very dusty objects. Whole progenitor nuclei in the interactions can be
missed if only optical HST imaging is used. Here we specifically present the
latest results regarding core-collapse supernovae found within the highly
extincted nuclear regions of these galaxies. Direct detection and study of such
highly obscured CCSNe is crucial for revising the optically-derived SN rates
used for providing an independent measurement of the SF history of the
Universe. We also present thus-far the first NIR luminosity functions of super
star cluster (SSC) candidates. The LFs can then be used to constrain the
formation and evolution of SSCs via constraints based on initial mass functions
and cluster disruption models.Comment: 6 pages. To appear in proceedings of 'Galaxies and their Masks'
(Namibia, April 2010), published by Springer, New York, eds. D.L. Block, K.C.
Freeman, I. Puerar
Simulations of galactic dynamos
We review our current understanding of galactic dynamo theory, paying
particular attention to numerical simulations both of the mean-field equations
and the original three-dimensional equations relevant to describing the
magnetic field evolution for a turbulent flow. We emphasize the theoretical
difficulties in explaining non-axisymmetric magnetic fields in galaxies and
discuss the observational basis for such results in terms of rotation measure
analysis. Next, we discuss nonlinear theory, the role of magnetic helicity
conservation and magnetic helicity fluxes. This leads to the possibility that
galactic magnetic fields may be bi-helical, with opposite signs of helicity and
large and small length scales. We discuss their observational signatures and
close by discussing the possibilities of explaining the origin of primordial
magnetic fields.Comment: 28 pages, 15 figure, to appear in Lecture Notes in Physics "Magnetic
fields in diffuse media", Eds. E. de Gouveia Dal Pino and A. Lazaria
Galaxies as simple dynamical systems: observational data disfavor dark matter and stochastic star formation
Genetic and Environmental Influences on the Development of Alcoholism: Resilience vs. Risk
On the Development of a Scalable 8-DoF Model for a Generic Parafoil-Payload Delivery System
The paper presents an initial move to develop a scalable high-degree-of-freedom model of the parafoil-payload system. The intention is to develop the tool capable of: i) determining basic system’s geometry parameters by observing the video data of the real descend, ii) readjusting the nominal aerodynamic and control coefficients incorporated into the well-established equations of motions, and iii) performing model identification to tune numerous relative variables to achieve the best fit with the real drop data if available. Since in the certain way such a tool would represent some kind of generalization of the modeling efforts undertaken so far, the present paper starts from a comprehensive review of publications devoted to the modeling of parafoil-payload systems. The paper then briefly addressed the current stage of the development of a scalable model. In anticipation of real drop data to validate the approach paper ends with conclusions. I