Polarimetric receiver in the forty gigahertz band: new instrument for the Q-U-I joint Tenerife experiment

This paper describes the analysis, design and characterization of a polarimetric receiver developed for covering the 35 to 47 GHz frequency band in the new instrument aimed at completing the ground-based Q-U-I Joint Tenerife Experiment. This experiment is designed to measure polarization in the Cosmic Microwave Background. The described high frequency instrument is a HEMT-based array composed of 29 pixels. A thorough analysis of the behaviour of the proposed receiver, based on electronic phase switching, is presented for a noise-like linearly polarized input signal, obtaining simultaneously I, Q and U Stokes parameters of the input signal. Wideband subsystems are designed, assembled and characterized for the polarimeter. Their performances are described showing appropriate results within the 35-to-47 GHz frequency band. Functionality tests are performed at room and cryogenic temperatures with adequate results for both temperature conditions, which validate the receiver concept and performance.     

A detailed two-dimensional stellar population study of M32

We present integral field spectroscopy of the     circumnuclear region of M32 obtained with the 2D_FIS fibre optics spectrographs installed at the 4.2-m William Herschel Telescope. From these spectra line-strength maps have been made for about 20 absorption lines, mostly belonging to the Lick system. We find good agreement with long-slit line-strength profiles in the literature, and no radial gradients in the azimuthally averaged absorption line indices. We fit the mean values of each spectral index and colours from the literature for the inner regions of M32 to the models of Vazdekis et al. and Worthey, finding that the present data can be well interpreted for a single stellar population of an intermediate age (∼4 Gyr) and a metallicity similar to solar         

Assessment of prospective geological hazards in Torrevieja-La Mata coast (western Mediterranean) based on Pleistocene and Holocene events

Natural Hazards - The coastal zone in which the lagoons of La Mata and Torrevieja (Eastern Spain) developed can be described as a compilation of geo-hazards typical of the Mediterranean realm. This...     

Radiation forces and the formation of planetary systems

We briefly support on some new results about the influence of the rotation and finite size of a stellar radiation source on dust particle orbits, emphasizing the possibility of stable orbits, in the equatorial plane, for dust sizes near the radiation pressure limit.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

Integral field spectroscopy of the gravitational lens HE1104‐1805

We present integral field spectroscopy of the double imaged quasar HE1104‐1805 taken with the optical fiber system INTEGRAL‐WYFFOS at theWHT telescope. From the spectra of the two components we have measured the continuum and line emission ratios, finding an offset between them that can be related to microlensing. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)