Herrera Aguilar, AlfredoMomennia, MehrabHERRERA AGUILAR, ALFREDO; 21161Villaraos Serés, Déborah Elizabeth2025-04-292025-04-292024-11https://hdl.handle.net/20.500.12371/27675"In this thesis, we work on the Schwarzschild-de Sitter background, which describes a static and spherically symmetric black hole immersed in a universe dominated by dark energy. We obtain the redshift expression of photons emitted by a massive particle circularly orbiting the black hole and detected by a far away observer with recessional movement due to the expansion of the universe. This redshift expression involves observable quantities, such as the redshift, with spacetime parameters, like the mass of the black hole and the cosmological constant. Thus, we apply this theoretical model to H2O megamaser systems,which consist on water vapor clouds emitting radiation on the microwave regime, located on accretion disks of black holes. By using astrophysical observations of the redshift, blueshift and position of the maser features, we perform a Bayesian statistical fit to estimate the parameters of mass, distance and position of the black hole, as well as the value of the Hubble constant, through its relation to the cosmological constant".pdfengCIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRAAstronomía--Astronomía descriptiva--Estrellas--Otros tipos particulares de estrellas--Agujeros negrosEcuaciones de campo de EinsteinDesplazamiento hacia el rojo--InvestigaciónConstante cosmológicaTesis de maestríaopenAccess