RADIOASTRONOMY

Author: DE GREGORIO MONSALVO ITZIAR.
Year: 2005.
University: AUTÓNOMA DE MADRID.
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS DE LA UNIVERSIDAD AUTÓNOMA DE AMDRID.

Summary: This thesis presents detailed study of the interaction of objects in low-mass young stellar with its surrounding environment, through the characterization of the physical, kinematics and the chemistry of their environment. These studies have been conducted using as a basic tool information provided by molecular emission lines on radio, through satellite observations only high sensitivity supplemented with interferometric observations. To this end, efforts are on the verge teams spectroscopy antenna 70 meters (DSS-63) located in the NASA space complex in Robledo de Chavela, Madrid. Introducing the systematic search for higher sensitivity máseres H2O in Bok globules, using the antenna DSS-63. As selection criteria choose indicators of stellar formation, as sources of radiocontinuo centers flows molecular peak molecular tracers high density and IRAS sources. We observed 207 positions and detect emission máser H2O in seven Bok globules (CB 3, CB 34, CB 54, CB 65, CB 101, CB 199 and CB 232). All except CB 3 are new detections, which are increasing from three to nine the number of Bok globules with emission máser known. This study is complemented by the first interferometric observations, using the VLA, in some of the Bok globules presenting máser H2O, finding the precise positions of these máseres. In the case of CB 3, CB 54, CB 101 and CB 232 identify their sources excitadoras. We conducted a search for issuance of CCS and ammonia to 1 cm in young stellar objects with presence máseres H2O as a sign of stellar formation. This search has been conducted with the antenna DSS-63, to study the physical properties, kinematics and the youth of these regions. We inferred the relationship between the presence of CCS and the physical properties of protoestrellas plants, their molecular flow and the issuance of NH3. We found that in regions stations CCS, NH3 presents maximum emission significantly more intense than in regions without release of CCS, but integrated intensities similar, which suggests half less turbulent, ie younger, in the first group. In addition, we get good candidates for further detailed studies to high resolution of kinematics and physical properties. This study was completed with interferometric observations, using the VLA, in CCS, NH3 and máseres H2O in the region surrounding the protoestrella B1-IRS. Kinematic studied the pattern of the region and its relationship with the characteristics of the surrounding environment. We found a pattern of velocity indicating a strong interaction gas charted by this molecule with a molecular flow in the region. This suggests the possibility of a local increase in the abundance of CCS through chemical-induced shocks. Besides witnessing for the first time a anticorrelación space between CCS and NH3 at scales of ~ 5.'' We demonstrate for the first time the feasibility of cross-calibration technique applied to thermal spectral lines with the VLA, noting simultaneously broadcast in CCS and máser H2O to 1 cm around the source IRAS 16293-2422 and using the intense emission of máseres H2O to chart weather changes to 1 cm. Finally, we present a promising statistical method for estimating the observational characteristics that may be more relevant in obtaining the physical parameters of hard protoplanetarios. To this end, we have developed a network of models emission line C17O (3-2) on discs protoplanetarios with different physical properties. As a preliminary result, this method allows to distinguish between relatively well disks with different radii. In addition, we present a study of detectability of our hard modeled with interferometers SMA and SPIRIT.

Author: PALAU PUIGVERT AINA.
Year: 2005.
University: BARCELONA.
Place of defense: FACULTAD DE FÍSICA.
Place of preparation: FACULTAD DE FÍSICA.

Summary: In this paper we have observed stellar formation of four regions in accumulation mode at wavelengths mm and submm with high angular resolution and high sensitivity. To carry out the selection process for the regions, there have been eight regions with the VLA and IRAM 30m. For each of the four regions selected, has studied the nature of the young stellar objects and the interaction between them. In the region of HH211 has not found evidence of interaction between the different sources. It has been studied with the SMA training one of the younger members, HH211mm, in the ongoing submm and the issuance of flow molecular CO (3-2) and SiO (8-7), and has found that a wind wide aspect seems to be the mechanism that drives the molecular flow from this source. In the case of IRAS 00117 +6412, observed with PdBI at 1 and 3 mm in N2H + (1-0), CS (5-4) and CH3OH (5-4), have been found in two sources compact mm . And the ionization front of the massive star has advanced one source mm and is about to reach the second source mm, so that this region is an excellent candidate for studying the interaction between the front ionizaicón and protostrellas formed around them. The region IRAS 20343 +4129 was observed with the SMA to 1mm and CO (2-1), and has discovered a molecular flow bipolar elongated in the east-west direction that is driven by an infrared source classified as Class I intermediate mass. It is proposed that other sources of infrared cavity is creating an environment and accumulating materials in its walls, painted by the condensation of dust have been detected. Finally, in the region IRAS 20293 +3952 was found two dense gas clouds charted by N2H + (1-0) and NH3 (1.1) and NH3 (2.2), and a variety of young stellar objects, Most associated with the northern part of the main cloud. Different stellar objects covering at least an order of magnitude in mass and are at different evolutionary states. It has been found that the chemical differentiation in the cloud is important, as well as the interaction between different sources. With these and other new data collected from the literature, has compiled a table of 5 regions candidates protostrellas high mass observed with sensitiviades better than 1 mass solar, and has been found that the number of sources mm around the protrostrellas high mass is less than the number of infrared sources around high-mass stars. Since our observations suggest that the formation in stellar clusters is continuing, the lowest number of sources mm suggests that the time scale in which a young stellar object is brilliant in mm is less than the time scale on which an object stellar young is bright in the infrared. Moreover, it has found a typical spatial scale of 0.1-0.3 pc associated with an evolutionary stage. Finally, the spatial distribution of the young stellar objects in the studied regions can be explained not only by the interaction between different objects, but also because the initial conditions of the original molecular cloud. Even so, the interactions can induce the formation stellar in some specific cases.

Author: MARTÍN RUIZ SERGIO.
Year: 2005.
University: COMPLUTENSE DE MADRID.
Place of defense: FACULTAD DE CIENCIAS FÍSICAS.
Place of preparation: INSTITUTO DE RADIOASTRONOMÍA MILIMÉTRICA.

Summary: This paper explores the possibilities of characterization and differentiation chemistry of galaxies through conducting sweeps in the range of spectral wavelengths milimétrico and submillimetre as well as its possible extrapolation to the nuclei of galaxies with high travel red, obscured in other spectral ranges. To this end is the first sweep spectral milimétrico done in an object extragaláctico, the region's nuclear galaxy formation with outbreaks of stellar NGC 253. We present a comparative study of the chemical composition of NGC 253 compared with a sample of galaxy. Likewise there is a comparison of the chemistry of this galaxy with a group of sources prototype within our Galaxy. Finally shows the preliminary results of spectral conducted sweeps in various positions within the region of the Galactic center, which will be used as benchmarks to determine the mechanisms of warming dominant in the central regions of galaxies NGc 253 and M 82.