RT info:eu-repo/semantics/masterThesis
T1 Cosmological observations with virtual radio telescopes
A1 Arriero López, Ángela María
A2 Máster Universitario en Astrofísica
AB The ground-based radio telescopes simulation software enable us to optimise the configuration of the telescope and its instrument dedicated to the observation of the Cosmic MicrowaveBackground (CMB). This type of observations requires very high sensitivity in data acquisition; therefore, designing a code that allows changing the properties of the telescope to obtainsimulated CMB maps is of great importance.Thus, the simulation of the GroundBIRD radio telescope currently located at the Teide Observatory in Spain was developed. For this, we used the classes and functions provided by theTOAST framework, a software developed in Python that supports telescope projects dedicatedto observing the CMB, such as Planck and LiteBIRD (space telescopes), and ground-basedprojects such as the Simons Array and CMB-S4. This work provides an adapted functionalcode made in Python that simulates the main features of the GroundBIRD telescope and generates intensity and polarization (Q-U) CMB maps from the Map-Making process developedby the TOAST framework, which uses the library Libmadam to remove correlated noise.Furthermore, the project shows the behavior of the polarization signals in EE and BB modebefore based on varying characteristics such as the integration time of the observations, thepolarization angles of the focal plane detectors, the Noise Equivalent Temperature (NET)of the detectors, the knee frequency of the 1/f noise and the elevation and scan speed ofthe telescope. It was observed that the noise level of the maps decreases significantly when:the integration time is longer; there are four rather than two polarization detector angles;the Noise Equivalent Temperature (NET) is reduced to 2.5 µK√s, and when the telescopeelevation is 60°. It was also found that the power spectrum of the output CMB signal issimilar to the input CMB when the knee frequency of the 1/f noise is less than 1 Hz andwhen the scan speed is 20 rpm.To conclude, we can say that the current features of GroundBIRD, based on the performedsimulations, allow measuring low power signals at low multipoles with relatively low noiselevels. However, the simulation could be improved to take into account real 1/f noiselevels, background effects due to polarization generated by thermal or synchrotron radiation,atmospheric noise, and ground signals.
YR 2022
FD 2022
LK http://riull.ull.es/xmlui/handle/915/32032
UL http://riull.ull.es/xmlui/handle/915/32032
LA en
DS Repositorio institucional de la Universidad de La Laguna
RD 08-nov-2024