Search results for "astronomía óptica"
showing 8 items of 8 documents
Estudio de pequeñas estructuras magnéticas de la fotosfera solar
2012
Se considera el campo magnético solar como el principal responsable del comportamiento global del Sol, pero continúa sin ser completamente comprendido. El estudio de las estructuras magnéticas revelan información relevante sobre los campos magnéticos que emergen en la superficie. En esta tesis se realiza un estudio de pequeñas estructuras magnéticas presentes en la fotosfera solar basado en medidas de intensidad. Además, se destaca la repercusión ejercida por la resolución de los instrumentos y la mejora de las técnicas observacionales. En primer lugar se amplía el estudio de la CLV del contraste de intensidad de pequeñas estructuras magnéticas presentes en la fotosfera, comparando su compo…
OMC: An Optical Monitoring Camera for INTEGRAL
2003
The Optical Monitoring Camera (OMC) will observe the optical emission from the prime targets of the gammaray instruments onboard the ESA mission INTEGRAL, with the support of the JEM-X monitor in the X-ray domain. This capability will provide invaluable diagnostic information on the nature and the physics of the sources over a broad wavelength range. Its main scientific objectives are: (1) to monitor the optical emission from the sources observed by the gamma- and X-ray instruments, measuring the time and intensity structure of the optical emission for comparison with variability at high energies, and (2) to provide the brightness and position of the optical counterpart of any gamma- or X-r…
First observations of the X-ray transient EXO 2030+375 with IBIS/ISGRI
2003
We present a first INTEGRAL observation of the 42s transient X-ray pulsar EXO 2030+375 with IBIS/ISGRI. The source was detected during Cyg X-1 observations in December 2002. We analyzed observations during the outburst period from 9 to 21 December 2002 with a total exposure time of ~770 kiloseconds. EXO 2030+375 was almost always detected during single ~30 minute exposures in the 18-45 energy bands. The source light curve shows the characteristic outburst shape observed in this source.
A photometric redshift of z = 1.8$^{\sf{+0.4}}_{\sf{-0.3}}$ for the AGILE GRB 080514B
2008
Aims: The AGILE gamma-ray burst GRB 080514B is the first burst with detected emission above 30 MeV and an optical afterglow. However, no spectroscopic redshift for this burst is known. Methods: We compiled ground-based photometric optical/NIR and millimeter data from several observatories, including the multi-channel imager GROND, as well as ultraviolet \swift UVOT and X-ray XRT observations. The spectral energy distribution of the optical/NIR afterglow shows a sharp drop in the \swift UVOT UV filters that can be utilized for the estimation of a redshift. Results: Fitting the SED from the \swift UVOT $uvw2$ band to the $H$ band, we estimate a photometric redshift of $z=1.8^{+0.4}_{-0.3}$, c…
INTEGRAL/SPI ground calibration
2003
Three calibration campaigns of the spectrometer SPI have been performed before launch in order to determine the instrument characteristics, such as the effective detection area, the spectral resolution and the angular resolution. Absolute determination of the effective area has been obtained from simulations and measurements. At 1 MeV, the effective area is 65 cm^2 for a point source on the optical axis, the spectral resolution ~2.3 keV. The angular resolution is better than 2.5 deg and the source separation capability about 1 deg. Some temperature dependant parameters will require permanent in-flight calibration.
SPI: The spectrometer aboard INTEGRAL
2003
SPI is a high spectral resolution gamma-ray telescope on board the ESA mission INTEGRAL (International Gamma Ray Astrophysics Laboratory). It consists of an array of 19 closely packed germanium detectors surrounded by an active anticoincidence shield of BGO. The imaging capabilities of the instrument are obtained with a tungsten coded aperture mask located 1.7 m from the Ge array. The fully coded field-of-view is 16º, the partially coded field of view amounts to 31º, and the angular resolution is 2.5º. The energy range extends from 20 keV to 8 MeV with a typical energy resolution of 2.5 keV at 1.3 MeV. Here we present the general concept of the instrument followed by a brief description of …
Clustering of galaxies: evolution, segregation, and baryon acoustic oscillations
2011
In this thesis, we tackle several open problems in the study of large-scale structure through the clustering of galaxies. To this end, we analyse data from some of the latest surveys, and we also develop new statistical techniques needed for this analysis in specific cases. In the first part, we focus on small and intermediate scales, where the relation between galaxy properties and their clustering (known as segregation) is important. The work in this part is driven by the exploitation of data from the ongoing Advanced Large Homogeneous Area Medium-Band Redshift Astronomical (ALHAMBRA) survey, which is perfectly suited to study the evolution of segregation trough cosmic time. We developed …
The INTEGRAL IBIS/ISGRI System Point Spread Function and Source Location Accuracy
2003
The imager on board INTEGRAL (IBIS) presently provides the most detailed sky images ever obtained at energies above 30 keV. The telescope is based on a coded aperture imaging system which allows to obtain sky images in a large field of view 29deg x 29deg with an angular resolution of 12'. The System Point Spread Function of the telescope and its detailed characteristics are here described along with the specific analysis algorithms used to derive the accurate point-like source locations. The derived location accuracy is studied using the first in-flight calibration data on strong sources for the IBIS/ISGRI system. The dependence of the calibrated location accuracy with the signal to noise r…