Cooperation reconsidered: the case of Comité del Pueblo in Quito

The case of Comité del Pueblo is an historical example, of a neighborhood of Quito created in the 70’s by a complex cooperative machine, which had the ability to overcome, legally, the shortcomings of the government. 5000 families in need of housing, an extreme left wing political party and a faculty of architecture, together in an impressive project of solidarity. A critical reflection on such example nowadays, uncovering the vanguard social figures of students, architects and urbanists, is not finalized to celebrate its premises, but rather to question the experience in the light of on-going Ecuadorian discussions on participation and inclusion. A lesson that probably deserves to be re-read as one of the scarce attempts to satisfy the right to the city in Quito.El caso de Comité del Pueblo es un ejemplo histórico de un barrio de Quito fundado en los 70’s. Diseñado y realizado a través de una compleja maquinaria cooperativa, hubo la capacidad de colmar legalmente, aunque sin involucrar al gobierno, una masiva demanda de vivienda. 5000 familias en necesidad de un hogar, un partido político de ‘extrema izquierda’, y la Facultad de Arquitectura de la Universidad Central de Quito trabajando juntos en un impresionante proyecto de solidaridad. La relevancia de considerar hoy en día este ejemplo, dejando patente las figuras vanguardistas de los estudiantes, arquitectos y urbanistas involucrados, no es para alabarlo, si no mas bien para cuestionarlo a la luz de la actual discusión sobre participación e inclusión en el Ecuador. Una historia que merece ser releída como uno de los escasos intentos de satisfacer el derecho a la ciudad en Quito

NANTEN 12CO (J=1-0) observations around the star WR 55

Context: A complete study of the molecular and ionized gas in the environs of the nebula RCW 78 around WR 55 is presented. Aims: The aim of this work is to investigate the spatial distribution, physical characteristics, and kinematical properties of the molecular gas linked to the galactic nebula RCW 78 to achieve a better understanding of its interaction with the star and with the ionized gas. Methods: This study was based on 12CO(1-0) fully sampled observations of a region of ~0.45{\deg} in size around the star WR 55 and the nebula RCW 78 obtained with the 4-m NANTEN telescope, radio continuum archival data at 1.4 and 4.85 GHz, obtained from SGPS and PMNRAO Southern Radio Survey, respectively, and available infrared MIPSGAL images at 24 microns. Results: A molecular gas component in the velocity range from ~ -58 to -45 km s-1, compatible with the velocity of the ionized gas, was found to be associated with the optical nebula. Adopting a distance of ~ 5 kpc, the mass of this molecular component is about 3.4 x 10^4 Msun. The analysis of the molecular data revealed the presence of a velocity gradient, in agreement with the Halpha line. New radiocontinuum flux density determinations confirm the thermal nature of RCW 78. This indicates that the ionized gas in RCW 78 arises from photoionization of the molecular gas component in the velocity range from -58 km s-1 to -45 km s-1. A molecular concentration at a velocity of -56.1 km s-1 (identified as C1) is very likely associated with the star HD 117797 and with a collection of candidate YSOs, lying at a distance of 3.9 kpc, while the rest of the molecular gas at velocities between -56 and -46 km s-1 constitute an incomplete ring-like structure which expands around WR 55 at a velocity of about ~ 5 km s-1. Mechanical energy and time requirements indicate that WR 55 is very capable of sustaining the expansion of the nebula.Comment: 14 pages, 10 figures.Accepted for publication in A&

Indice espectral tomográfico de la nebulosa de Gum

Hemos utilizado los datos de los relevamientos en continuo de radio en 408, 1420, 22800 y 33000 MHz, con el fin de estudiar la distribución del índice espectral en la región de la nebulosa de Gum. Después de la substracción de la emisión térmica subyacente, hemos aplicado la técnica de la Tomografía y hemos encontrado variaciones en el índice espectral de temperatura β entre el IRAS Vela Shell (IVS), una prominente estructura en forma de anillo, y la nebulosa de Gum. Estos resultados darían más apoyo a la idea de que ambas son estructuras diferentes.We have used the radio continuum survey data at 408, 1420 , 22800 and 33000 MHz in order to study the spectral index distribution in the Gum nebula region. After subtraction of the underlying thermal emission, we have applied the tomography technique and we found variations in the radio continuum temperature spectral index between the IRAS Vela shell (IVS), that is a prominent ring-like feature, and the Gum nebula. These results would provide further support to the idea that both structures are different.Fil: Testori, Juan Carlos. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomia; Argentin

A statistical analysis of a Galactic all sky survey at 1.4 GHz

Radio surveys at frequencies of about 1 GHz allow to map the synchrotron emission in a frequency range where (except for very low Galactic latitudes or towards localized regions) it dominates over the other radio components. New all sky total intensity and polarization data at 1.4 GHz have been recently collected. We focus on the Galactic radio emission correlation properties described in terms of angular power spectrum (APS). We present for the first time the APS, in both total intensity and polarization modes, for some representative Galactic cuts and suitable APS power law parametrizations.Comment: Comments: 2 pages, 2 figures; in Astronomische Nachrichten, Vol.327, Issue 5/6, p.491 (2006); Proceedings of International Conference "The Origin and Evolution of Cosmic Magnetism", 29 August - 2 September 2005, CNR Area della Ricerca, Bologna, Italy, eds. R. Beck, G. Brunetti, L. Feretti, and B. Gaensle

The embedded clusters DBS 77, 78, 102, and 160-161 and their link with the interstellar medium

Aims. We report a study of the global properties of some embedded clusters placed in the fourth quadrant of the Milky Way to clarify some issues related with their location into the Galaxy and their stellar formation processes. Methods. We performed BVI photometric observations in the region of DBS 77, 78, 102, 160, and 161 clusters and infrared spectroscopy in DBS 77 region. They were complemented with JHK data from VVV survey combined with 2MASS catalogue, and used mid-infrared information from GLIMPSE catalogue. We also searched for HI data from SGPS and PMN radio surveys, and previous spectroscopic stellar classification. The spectroscopic and photometric information allowed us to estimate the spectral classification of the brightest stars of each studied region. On the other hand, we used the radio data to investigate the interstellar material parameters and the continuum sources probably associated with the respective stellar components. Results. We estimated the basic physical parameters of the clusters (reddening, distance, age, and initial mass function). We searched for HII regions located near to the studied clusters and we analyzed the possible link between them. In the particular case of DBS 160-161 clusters, we identified the HI bubble B332.5-0.1-42 located around them. We found that the mechanical energy injected to the interstellar medium by the more massive stars of this couple of clusters was enough to generate the bubble.Comment: 15 pages, 14 figures, 6 tables, accepted for publication in A&

Measuring and calibrating Galactic synchrotron emission

Our position inside the Galaxy requires all-sky surveys to reveal its large-scale properties. The zero-level calibration of all-sky surveys differs from standard 'relative' measurements, where a source is measured in respect to its surroundings. All-sky surveys aim to include emission structures of all angular scales exceeding their angular resolution including isotropic emission components. Synchrotron radiation is the dominating emission process in the Galaxy up to frequencies of a few GHz, where numerous ground based surveys of the total intensity up to 1.4 GHz exist. Its polarization properties were just recently mapped for the entire sky at 1.4 GHz. All-sky total intensity and linear polarization maps from WMAP for frequencies of 23 GHz and higher became available and complement existing sky maps. Galactic plane surveys have higher angular resolution using large single-dish or synthesis telescopes. Polarized diffuse emission shows structures with no relation to total intensity emission resulting from Faraday rotation effects in the interstellar medium. The interpretation of these polarization structures critically depends on a correct setting of the absolute zero-level in Stokes U and Q.Comment: 10 pages, 8 figures. To be published in "Cosmic Magnetic Fields: From Planets, to Stars and Galaxies", K.G. Strassmeier, A.G. Kosovichev & J.E. Beckman, eds., Proc. IAU Symp. 259, CU

A CGPS view of the ISM towards HD 192281

Massive stars are known to have a profound impact on their surroundings through their high ionizing radiation, their strong stellar winds, and their eventual final explosion as supernovae. Within the area surveyed by the CGPS project there are 87 O-type stars and 36 Galactic Wolf-Rayet stars. Therefore, the CGPS is an ideal database to study, in a large number of stellar targets, the interaction of massive stars (and their descendants) with their surroundings. In this paper we report on a study carried out towards the massive stars HD 192281. A shell-like structure, detectable at radio continuum, infrared and neutral hydrogen wavelengths, is found to be associated with this star.Fil: Cappa, Cristina Elisabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto Argentino de Radioastronomia (i); ArgentinaFil: Arnal, Edmundo Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto Argentino de Radioastronomia (i); Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Cichowolski, Silvina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Testori, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio(i); ArgentinaFil: Pineault, Serge. Université Laval. Département de Physique. Québec; Canad

A multifrequency angular power spectrum analysis of the Leiden polarization surveys

The Galactic synchrotron emission is expected to be the most relevant source of astrophysical contamination in cosmic microwave background polarization measurements, at least at frequencies 30'. We present a multifrequency analysis of the Leiden surveys, linear polarization surveys covering essentially the Northern Celestial Hemisphere at five frequencies between 408 MHz and 1411 MHz. By implementing specific interpolation methods to deal with these irregularly sampled data, we produced maps of the polarized diffuse Galactic radio emission with pixel size of 0.92 deg. We derived the angular power spectrum (APS) (PI, E, and B modes) of the synchrotron dominated radio emission as function of the multipole, l. We considered the whole covered region and some patches at different Galactic latitudes. By fitting the APS in terms of power laws (C_l = k l^a), we found spectral indices that steepen with increasing frequency: from a = -(1-1.5) at 408 MHz to a = -(2-3) at 1411 MHz for 10 < l < 100 and from a = -0.7 to a = -1.5 for lower multipoles (the exact values depending on the considered sky region and polarization mode). The bulk of this steepening can be interpreted in terms of Faraday depolarization effects. We then considered the APS at various fixed multipoles and its frequency dependence. Using the APSs of the Leiden surveys at 820 MHz and 1411 MHz, we determined possible ranges for the rotation measure, RM, in the simple case of an interstellar medium slab model. Taking also into account the polarization degree at 1.4 GHz, we could break the degeneracy between the identified RM intervals. The most reasonable of them turned out to be RM = 9-17 rad/m^2.Comment: 18 pages, 14 figures. Astronomy and Astrophysics, in pres