Recent Talks

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.

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.

The Stratospheric Observatory for Infrared Astronomy (SOFIA) is now performing scientific observations and the results of the second open observing cycle solicitation is about to be announced.  With an available wavelength coverage from the visual to sub-mm wavelengths and a long life time - including planned instrument upgrades, SOFIA will provide critical resource for the astronomical community for the next decade and beyond.  Current and expected SOFIA instruments provide heterodyne spectroscopy in the THz band, including the line of [O I], [C II] and [N II] as well as OH, HD and many other hydrides, at high spectral resolution.  Echelle spectroscopy in the Mid-infrared (MIR) which will allow observations of e.g. fine-structure lines of and H₂ pure rotational lines.  These will help address questions of interstellar chemistry and physics in star forming regions, PDRs and galaxies.  Mid-infrared (MIR) grism spectroscopy, of e.g. dust and ices, can be used to address questions of the freeze-out of molecules from the gas phase to better understand the formation, destruction and characteristics of interstellar ices.  Imaging in the MIR and FIR and FIR polarimetry can provide a more complete picture of the temperature, density and magnetic field structure of e.g. star forming cores. I will highlight the current and expected capabilities of SOFIA and some of the early science results achieved.

The ALHAMBRA (Advance Large Homogeneous Area Medium Band Redshift Astronomical; Moles et al. 2008) survey has observed 8 different regions of the sky, including sections of the COSMOS, DEEP2, ELAIS, GOODS-N, SDSS and Groth fields using a new photometric system with 20 contiguous, ~300A width, filters covering the optical range, plus deep JHKs imaging. The observations, carried out with the Calar Alto 3.5m telescope using the wide field (0.25 deg2 FOV) optical camera LAICA and the NIR instrument Omega-2000, correspond to ~700hrs of on-target science images. The photometric system was specifically designed to maximize the effective depth of the survey in terms of accurate spectral-type and photometric redshift estimation along with the capability of identification of relatively faint emission lines.

The ALHAMBRA Gold catalogue corresponds to a subsample of ~100k bright galaxies (+20.000 stars in the galactic halo and ~1000 AGN candidates), photometrically complete down to magnitude I=23AB, with very accurate and reliable photometric redshift estimations.

Considering that the Spanish community will have privileged access to the data until Nov15th 2013, this seminar is intended to be a brief introduction to the potential (doable) science with the ALHAMBRA-survey.

Galaxies in different environments have different properties. In dense environments galaxies are more likely to be red, passive ellipticals than in less dense environments. This difference can be detected both on small and large-scale environments. In this talk, I will present results on galaxy populations in different environments on two scales: the group scale and the supercluster scale. The goal of our project is to find out if there are differences between massive galaxies in similar groups, but different large-scale environments. The results will tell if the evolution of galaxies is fully determined by the mass of their dark matter halo, or if the large-scale environment also play a role.