COSMIC RAYS

Author: LÓPEZ MOYA MARCOS.
Year: 2006.
University: COMPLUTENSE DE MADRID [www.ucm.es].
Place of defense: FACULTAD DE CIENCIAS FÍSICAS.
Place of preparation: FACULTAD DE CIENCIAS FÍSICAS, UNIV. COMPLUTENSE DE MADRID.

Summary: In recent years, Astronomy very high energy gamma is seen rapid development thanks to the launch of a new generation of Cherenkov telescopes. These telescopes not "see" the source directly under observation, but that detect the Cherenkov light emitted in the cascade of particles that occurs when the gamma rays enter the Earth's atmosphere. This technique solves the problem of opacity of land to the gamma rays, and she has managed to find numerous sources ray gammas high energy, among which are such remnants of supernovae, galaxies core assets and microcuásares. Among the new telescopes launched recently highlights the MAGIC telescope, with its 17 m diameter is the greatest Cherenkov telescope built so far. MAGIC is located in the astrophysical observatory of the Roque de los Muchachos on the island of La Palma, participating in the project more than 150 scientists from 18 research centers and universities. The thesis begins the current state of gamma astronomy, describing the types of sources, as well as mechanisms for broadcast. The following explains the technique can detect gamma emission from the earth from these sources. To do this, describes the physics of atmospheric waterfalls, with special emphasis on the differences between those initiated by gamma rays created by the enormous depth of cosmic rays. After describing the MAGIC telescope, stressing mainly technical developments which incorporates, explained in detail the chain of analysis implemented for the analysis of the first data taken by the telescope. It pays special importance to new techniques used to separate the signal gamma background hadrónico, especially at low energies, and the method for estimating energy rays gammas originated waterfalls detected. These techniques are then employed in the analysis and study of the Crab Nebula. The results show a curvature of the spectrum is this energy source to near 100 GeV, indicating that its broadcast these energies originates as a result of the inverse Compton scattering of photons with electrons Synchtron of the nebula. The second part of the thesis concerns the search for gamma-ray pulsars with MAGIC. The pulsars have always been one of the main objectives of the gamma astronomy, but has not yet been achieved ever since detect land Cherenkov telescopes. The reason is that the emission from these sources appears to decline very sharply energies of a few tens of GeV, although unknown details of this phenomenon by the lack of comments in this energy range. It requires a telescope with a low threshold observation as MAGIC, in order to determine the mechanism responsible for the production of gamma rays in the magnetosphere of the neutron stars. For this purpose, first started studying the signal expected pulares to GeV energies as current theoretical models, for which we have developed a program that simulates the main physical processes that take place in the vicinity of the neutron stars. This code enables us to predict on the basis of the parameters of press, such as your period of rotation and magnetic field, the spectrum and light curve expected. Then, on the basis of both the theoretical expectations and the comments made at lower energies by the EGRET satellite, investigates the capacity of MAGIC to detect pulsars, and concludes with a catalog with the best candidates to be observed. Finally, having described the techniques used to search for the emission of gamma press Crab among the data taken by MAGIC. In anális 8 is reali 42c themselves no evidence has been found of such issuance, thus having obtained upper limits that restrict the possible mechanisms of emission. Among one of the results of the work done, is to have proven the feasibility of extending the astronomy Cherenkov telescopes until energies less than 100 GeV. Future improvements will incorporate techniques MAGIC, and especially the construction of a second telescope that will operate alongside the existing stereo mode, enable further lower detection threshold in the Cherenkov telescopes, consolidated as an essential complement to comments made since space.