Recent Talks

List of all the talks in the archive, sorted by date.


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Tuesday November 12, 2013
Dr. Oleg Kochukhov
Uppsala University

Abstract


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Tuesday November 12, 2013
Dr. Oleg Kochukhov
Uppsala University

Abstract


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Monday November 11, 2013
Dr. Fausto Cattaneo
University of Chicago

Abstract


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Monday November 11, 2013
Dr. Fausto Cattaneo
University of Chicago

Abstract


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Monday November 11, 2013
Dr. Phil Judge
High Altitude Observatory

Abstract


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Monday November 11, 2013
Dr. Phil Judge
High Altitude Observatory

Abstract


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Monday November 11, 2013
Dr. Phil Judge
High Altitude Observatory

Abstract


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Tuesday November 5, 2013
Dr. ZengHua Zhang
IAC

Abstract

 

Studying the Halo via Its NEarby low-mass Dwarfs (SHINED) is an ongoing project aiming to understand the Galactic halo with metal-deficient low-mass stars (LMS) and brown dwarfs (BD). At the first stage of the project we are focusing on the discovery and characterisation of halo LMS and BD. I give an overview of the SHINED project then brief discuss the proprieties of halo LMS and BD. I introduce the main results of our work on red subdwarf binaries (Zhang et al. MNRAS, 434, 1005). I talk more about our work on the search of L subdwarfs from SDSS and UKIDSS. I discuss the spectral types of L subdwarfs, and spectral signature of halo BD. I also discuss the location of the Substellar Subdwarf Gap predicted by low-mass evolutionary models.

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Tuesday October 29, 2013
Dr. Frederick Poidevin
IAC

Abstract

I will present an extensive analysis of the 850 microns (353 GHz) polarization maps of the SCUBA Polarimeter Legacy (SCUPOL) Catalogue produced by Matthews et al., focusing on the molecular clouds and star-forming regions. The first half of the presentation will concern the several methods used in order to analyze and characterize the observed polarization maps and a statistical analysis of the results will be presented. The second half of the talk will focus on a method used for describing the turbulent regimes of the four well sampled regions, S106, OMC-2/3, W49, and DR21, based on comparisons with three-dimensional magnetohydrodynamics (MHD) numerical simulations scaled to the observed polarization maps. It will be shown how this method can be used for constraining the values of the inclination angle of the mean magnetic field with respect to the line of sight. Consistency of the results obtained from the comparison of the information extracted from the analysis of the observed and simulated maps with results obtained from independent observation data analysis by other authors will be discussed. Conclusions regarding how simple, ideal, isothermal, and non-self-gravitating MHD simulations may be sufficient in order to describe the large-scale observed physical properties of some molecular cloud envelopes will be given.


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Thursday October 24, 2013
Dr. Alberto Sainz-Dalda
Stanford-Lockheed Institute for Space Research

Abstract

Flares are among the most energetic magnetic solar phenomena. They are often accompanied by ejections of charged particles, which have a direct influence on the Earth in terms of Aurora or radio and satellite outages. The sudden nature of flares - some of them only last minutes - makes them an elusive feature when observed from ground-based telescopes. These measurements are especially challenging when we focus on magnetic fields and velocities in the different solar layers where flares develop and occur. I will present flare observations taken with different instruments, each targeting different observables, and I will show what we can learn from ground-based polarization measurements.